IVth Meeting of
Asian Crystallographic Association
atIndian Institute of Science
Bangalore, India

AsCA '01
IV Meeting of
Asian. Crystallographic Association
atIndian Institute of Science
Bangalore, India

18 - 21 November 2001
sponsored and supported byIndian National Science Academy
Indian Crystallographic Association
Department of Science and Technology, Govt. of India
Indian Institute of Science
Jawaharlal Nehru Centre for Advanced Scientific Research
Asian Crystallogrpahic Association
Intemational Union of Crystallography
with corporate support from

Bruker- Nonius
Philips Analytical
Rigaku Intemational, JapanX- ray Research (MAR Research), Germany

ABSTRACTS

Keynote AddressKl-1

DIRECT ME'IHODS FOR SOLVING CRYSTAL S'IRUCTURES FROM DIFFRACTION
DATA.

Henk Schenk, Laboratory for Crystallography, IMC, FNWI, University of
Amsterdam, Nieuwe Achtergracht 166, 1018WV Amsterdam, The Netherlands.
Direct Methods to solve crystal structures from diffraction data have a long
history, as long as the history of the Journals of the IUCr themselves. Already inthe first issue of Acta Crystallographica back in 1948, the article of Harker andKasper about the inequalities appeared and since then almost no issue of Acta
was without contributions to the field . For instance, most of the publications of
the Nobel laureates Herbert Hauptman and Jerome Karle came out in Acta. In
1952 there was the famous article of David Sayre about the squaring equation.
Also the breakthrough of Direct Methods in real structure determination with
Isabella Karle and Michael Woolfson in essential roles can be followed there. And
much, much more, too much for an abstract. Our community is very fortunatethat for present subscribers of Acta in due course all back issues will be available
Online,. so that all of this will be available at a mouse click.
I was a primary school kid at the time of the start of Direct Methods and as a
student in Chemistry I became interested in crystallography in 1962. From 1965,
when I took up a PhD study with Carolina MacGillavry. I am a crystallographer.
At the time in Amsterdam, we were living in the ALGOL programming world andmost programs available were in the other language, FORTRAN. Therefore we had
to write many computer programs ourselves and so I became active in Direct
Methods in 1967.
'
My lecture will be dealing with the past, present and future of Direct Methods forsolving Crystal Structures. As a matter of course, I will give special attention tosome of the contributions of the Amsterdam group in this field , such as :1. The symmetry properties of triplet solutions in different space groups.
2 . Positive and negative quartet relations.
3 . Enantiomorph specific phase extension and refmement.
4. Structure determination from powder data.
Email: schenk@science.uva.nl.

Plenary LecturePL-1
EVIDENCE OF SUB1LE EIEC1RONIC 1RANSmONS IN X-RAY DIFFRAC110NS'IUDIES OF MA1ERIALS UNDER PRESSURE

S.K. Sikka, Atomic and Condensed Matter Physics Group, Bhabha Atomic
Research Centre, Mumbai 400 085, India
Use of x-ray diffraction for detection and characterization of phase transitions anddetermination of equations of state of materials is now very well established inhigh pressure science. Though these, many theoretical concepts in the electronic
band structure theory of solids like s-d electron transfer, f electron delocalization,
valence transitions, insulator to metal transitions etc. have been verified. With
the availability of synchrotron sources, precision x-ray powder diffraction isincreasingly being used to detect subtle effects due to Fermi surface tropology
changes like Lifshitz transitions etc. These manifest here as second order like
phase transitions or deviations from linearity in universal forms of equations ofstate. In this talk, we illustrate this aspect by examples mostly taken from ourown work.
Email : sksikka@magnum.barc.ernet.in

PL-2
CRYSTAL STRUCTURE OF TilE ADRENALINE SYNTIIESISIZING ENzyME PNMT

Jennifer L. Martin 1 , Jake Begunl, Michael J. McLeish2, Joanne M. Caine2 andGary L. Grunewald3, 1Centre for Drug Design and Development and Special
Research Centre for Functional and Applied Genomics, Institute for Molecular
Bioscience, University of _Queensland, Brisbane QLD 4072 Australia, 2 Victorian
College of Pharmacy, Monash University, Parkville VIC 3052 Australia, and3Department of Medicinal Chemistry, The University of Kansas , Lawrence Kansas.
66045-2506 USA.
Adrenaline , also known as epinephrine, is a catecholamine produced in theadrenal glands and in the CNS to induce specific biologic effects. In the periphery.
the effects of adrenaline are well-known. Its release from the adrenal medulla istriggered by excitement or physical stress and induces the "flight-fight" response,
so-called because it prepares the body for immediate and energetic activity. The
response results in an increase in heart rate , blood pressure, blood sugar.
metabolic rate and bronchodilation. In the CNS, the effects of adrel)aline are notso well understood. Ideally, to investigate the central effects of adrenaline achemical is required that crosses the blood brain barrier, potently inhibits theadrenaline synthesizing enzyme PNMT and does not affect other catecholamine
processes . Currently available PNMT inhibitors do not meet these criteria. We
have determined the structure of PNMT to enable the design of such compounds.
The crystal structure of human PNMT is solved at a resolution of 2 .4 A andincludes a bound cofactor product and inhibitor. The structure reveals a highly
decorated methyltransferase fold , with an active site protected from solvent by anextensive cover formed from several discrete structural motifs. The inhibitor
interacts with the enzyme in a different mode from the modeled substratenoradrenaline. Specifically, the position and orientation of the amines are notequivalent. An unexpected finding is that the structure of PNMT provides
independent evidence of both backwards evolution and fold recruitment in theevolution of a complex enzyme from a simple fold .
Email: J.Martin@imb.uq.edu.au

PL-3
STRUCnJRE ANALYSES BY 1HE MAXIMUM EN1ROPY METIIOD

Makoto Sakata. Masaki Takata and Eiji Nishibori, Department of Applied Physics.
Nagoya University. Nagoya, 464 8603, JapanThe Maximum Entropy Method (MEM) is a statistical deduction that can yield ahigh-resolution electron density distribution from a limited number of X-ray
diffraction data without using any structural model. Because of this ability, MEM
enables us to obtain an accurate electron density distribution from X-ray powder
diffraction data, particularly from synchrotron powder data. For the above
purpose, a sophisticated method has been developed , that is, the MEM/Rietveld
analysis .
The MEM/Rietveld analysis is an iterative way in combination with the MEM and
Rietveld analyses . In this method, the final MEM electron density distribution isderived self-consistently with the structural model used in the Rietveld
refinement. In the process of the iteration, the structural model for Rietveld
refinement is normally constructed from the previous MEM electron density
distribution. At the start of the iteration. it is necessary to have a primitive
structural model. The method has been successfully applied to the structurestudies of fullerene compounds, intermetallic compounds, manganites , etc.
In the talk, not only the methodology but also quite a few recent results, mostly
obtained from third generation SR data. will be presented . The experimental
technique for high or low temperature structure a nalyses by MEM will be also
given.
Email : a40366a@nucc.cc.nagoya -u.ac .jp

PL-4

PRO'IEJN CRYSTALLOGRAPHY IN 1HE 21ST CENTURY: S1RUCTURES AND
MECHANISMS

G. Guy Dodson, Department of Chemistry, University of York, York YOl 5DD,
England.
Synchrotron radiation has made possible high throughput techniques in X-ray
crystallography. The capacity to solve crystal structures is now starting to matchthe enormous challenge of genome sequences. It is however not just in simple
structure determination that the new techniques are important, it is now
increasingly possible to dissect the structural and chemical basis of protein
reactions such as catalysis. The serine hydrolases have been a key enzyme in thehistory of biochemistry and protein crystallography. Recent research has revealed
the complexity of their evolutionary pattern and the intricate geometricaladjustments that occur in substrate binding and catalysis. It is possible toillustrate these phenomena from a range of such enzymes as subtilisin, trypsin,
penicillin acylase and other serine hydrolases.
Email: ggd@yorvic.york.ac.uk

Al : Fo un dat ion , the ory an d
his tor y of cry sta llo gra ph yAl-lAN EMPIRICAL STUDY ON USING FREER-VALUES IN CRYSTAL STRUCTURE
ANALYSIS OF SMALL MOLECULES: RESOLUTION OF SPACE GROUPAMBIGUITY
A. Abdul Ajees. S. Parthasarathy, Department of Crystallography and Biophysics,

University of Madras , Guindy campus, Chennai- 600 025 , India.
The utility of freeR-value in m a cromolecular crystal structure analysis is now wellknown. In this paper a possible application of this concept to small molecule
crystallography is discussed. It is not infrequent that in crystals whose spacegroup could be either Cc or C2 I c, crystallographers generally determine andrefine the structure in both space groups and choose the one which leads tobetter values for bond lengths and angles. It would be useful to device asomewhat simpler method for doing this. In this paper a method of using the free
R-value concept for this purpose is discussed. The advantage of the present
method is that it enables us to choose the correct structure by comparing thevalues of a single index (i.e .. free R-value} for the structures in the two possible
space groups and choosing the one leading to a lower freeR-value.
Various types of R-values have been proposed in the literature for use in crystal
structure analysis and they have been found to behave differently in the various
stages of structure analysis 1 . It is therefore useful to make a comparative studyof the different types of free R-values in order to find their relative efficacy inrelation to the present problem of resolution of space group ambiguity. The
results obtained from such a study will also be reported .
!.Srinivasan, R. & Parthasarathy, S. (1976}. Some statistical Applications in X-ray
Crystallography, Pergamon press ltd .. UK.
Email: alazeez34@yahoo.com

Al-2

A STACKING FAUL'IED S1RUCTURE REQUIRING A STATISTICAL DISTRIBUTION
1HAT VARIES BE1WEEN MOSAIC BLOCKS
A. David Rae, Anthony C. Willis, Connie K. Y. Lee and Christopher J. Easton,

Research School of Chemistry, Australian National University, Canberra, ACT
0200, Australia.
Layers of 4-methoxycarbonyl-5 -methyl-3-phenyl-D2-isoxazole, [apparent cell a20 .9645(6). b 9.4287(3). c 10.8461(3) A. ~ 90.0°, P2Ifc, Z = 8 ] have P2 1 /csymmetry but stack perpendicular to a* so that adjacent layers are related byeither a translation of l/2+x.y.zor a 2 1 screw axis 1/2+x,1/2-y,-z. Only adjacentlayers related by the 2 1 screw axis can contribute to the h odd reflections whichshow orthorhombic diffraction symmetry with systematic absences consistent
with P2 1 ca. The structure factor can be written as the sum of the contributionsof two layers, each unequally disordered between sites related by x , 1/2-y,-z.
Possible ordered structures are two x,l /2 -y,-z related P2Ifc structures and two
Refining layer populations and includ'i.ng a
1/2+x,y,z related Pbca structures.
twinning parameter does not give a satisfactory refinement. However, successfulrefinement was possible if the observed reflections were considered to haveintensities that were the sum of contributions from individual mosaic blocks withwidely varying parameters for the layer disordering. Details will be presented.
Email : rae@rsc.anu .edu.au

Al-3
PREDICTION OF B1JVOET RATIO MEASUREMENT FOR MACROMOLECULESNEAR THE L-ABSORPTION EDGES OF Hg AND Pt WITH SYNCHROTRONRADIATION

D.Velmurugana, K.Sekarb , S.Shanmuga Sundara Raj c and Takashi Yamanec.
aDepartment of Crystallography and Biophysics. University of Madras , GuindyCampus , Chennai, 600025, bBio-Informatics Centre, Raman Building, Indian
Institute of Science, Bangalore, 560012 , coepartment of Biotechnology, Graduate
School of Engineering, Nagoya University, Nagoya 464-8603 , Japan
Multi wavelength anomalous scattering experiment has b ecome a powerful tool inthe structure elucidation of macromolecules using synchrotron radiation. The
u se of data measurement at a s ingle wavelength near the absorption edge is also
pointed out recently. In these methods the Bijvoet difference measurement ismainly involved.
The presentation will describe the statistical method ofpredicting the percentage of reflections, which will have a Bijvoet ratio greaterthan a given threshold limit for a truncated data.
The analysis involves
macromolecules of various complexities with Hg or Pt derivative and results arepresented for a wide range of wavelengths u sed in data collection usingsynchrotron radiation. The results clearly confirm the advantage one can obtainin Bijvoet ratio measurement at wavelengths where pronounced anomalous
scattering effect occurs. Furthermore, the availability of a sufficiently large
percentage of reflections with la rge values of Bijvoet ratio due to the enhanced
anomalous scattering effect with synchrotron radiation may make the phasedetermination procedure in macromolecules more effective.
Email: d_velu@yahoo .com

Al-4

REAL-SPACE REPRESENTATION OF ATOMIC FLUCTUATIONS IN 1ERMS OF
QUANTITATIVE ANALYSIS OF X-RAY DIFFUSE SCAT1ERING - APPLICATION TO
DISORDERED PEROVSKI1E RELAXOR PMN· Naohisa Takesuea, Yasuhiko Fujiia, and Hoydoo Youb, aNeutron Scattering
Laboratory, Institute for Solid State Physics, The University of Tokyo, 106-1
Shirakata, Tokai, Ibaraki 319- 1106, Japan, and bArgonne National Laboratory.
Materials Science Division, 9700 South Cass Avenue, Argonne, Illinois 60439,
USA.

Disordering of atoms, ionic charges. and electron spins in crystals occasionallycauses remarkable variation of the physical properties. Keys to elucidate themechanisms are sometimes given by studying local crystal structures throughquantitative analysis of diffuse scattering. This kind of investigations has been
applied to chemical short-range order in alloys since 1950s, and the applicability
is to extend toward different matters such as dielectric systems and stronglycorrelated electronic systems, in the present time. In this study, we selected fromthe former systems a special kind of ferroelectrics, relaxor Pb(Mg 113 Nb 2 ; 3l03
(PMN). exhibiting a diffuse cubic-to-rhombohedral phase transition and dielectricdispersion near 270K, and investigated the atomic fluctuations using an x-ray
diffuse scattering technique to explain a mechanism of the abnormal behavior.
From the measurement, ionic-pair displacement correlation functions have been
determined quantitatively around 270K. The results show the strongrhombohedral-polar correlations regarding Pb-0 , Mg/Nb-0, and 0-0' pairs. Their
spatial distribution at 300K forms an ellipse or a sphere with the diameters of 30BOA. and the sizes are reduced to 30-40A on cooling through local condensationof thermal la ttice fluctuations. This direct observation of the local structure
proves the presence of the polar microregions in the paraelectric state which leads
to the dielectric dispersion.
Email : ta:kesue@issp.u-tokyo .ac.jp

Al-5
X-RAY RESONANCE PHASE: MULTI-BEAM DIFFRACTION EXPERIMENTS AND
THE RESONANCE PERTURBATION BETHE APPROXIMATION

Y.P. Stetskoa,b, G.Y. Lina, Y.S. Huanga, C.H. Chaoa, Y.R. Leea, and S.L. Changa.b,
anepartment of Physics , National Tsing Hua University, bSynchrotron Radiation
Research Center, Hsinchu, Taiwan, R.O.C.
X-ray diffraction/scattering for atoms in excited states or under resonanceconditions has currently been used to probe atomic and electronic structures ofmatter. In the case of multiple diffraction at atomic absorption edges, the effects
of anomalous dispersion on multi-wave x-ray interference in crystals areinteresting and important topics to investigate. In this paper, highly phasesensitive profiles of the diffraction intensity ratios of two inversion-symmetryrelated multiple diffractions at absorption edges exhibiting strong asymmetriccharacteristics, compared with those far from the edges, are experimentally andtheoretically observed . The changing of asymmetry of these ratios results fromthe anomalous dispersion corrections in the structure factors due to thesignificant change of the resonance phase at the absorption edge. The excellent
agreement between the experimental and theoretical results is obtained. The
proposed resonance perturbation Bethe (RPB) approach allows for thedetermination of the changes of x-ray reflection phases under resonanceconditions. This provides a highly sensitive way for experimental investigation of
the spectral distribution of reflection phase shift due to the resonance.
Email: slchang@phys.nthu .edu.tw

Al-6

PHASE DETERMINATION FOR MACROMOLECULAR CRYSTALS USINGSTEREOSCOPIC MULTI-BEAM IMAGING: DATA ANALYSIS AND TIIEORETICALCONSIDERATION

C.H. Chaoa, b, C.Y. Hung 3 , -Y.S. Huang3 , C.H . Ching3 , Y.R. Lee 3 , S.C. Lai 3 , Y.P.
Stetskoa.c, H. Yuand and S.-L. Changa.b. 3 0epartment of Physics , National Tsing
Hua University, bSynchrotron Radiation Research Center, Hsinchu , Taiwn,
cchemovtsy State University, Chemovtsy, Ukraine & ctlnstitute of
R.O.C.,
Molecular Biology, Academia Sinica, Taipei. Taiwan, R.O.C.
A detailed analysis of multiple diffraction data collected by the stereoscopic multibeam imaging technique from a hexagonal lysozyme crystal is reported.
Calculations based on the dynamical theory are employed for macromolecular
crystals subject to the crystal rotation for stereoscopic imaging and theconventional Renninger azimuthal scan. The . multi-beam intensity profile
formation and the relationship and mutual influence between the two scans areinvestigated. A simple practica l method of quantitative estimation of the reflection
phases of structure-factor multiplets from the experimental data obtained with two
inversion-symmetry-related diffractions is proposed. The procedures for data
handling and for distinguishing "partial" diffraction images from "full" diffraction
images are also developed considering the multi-beam geometry and experimental
conditions. These procedures provide a practical way of reconstructing diffraction
profiles for experimental phase determination.

Email : slchang@phys.nthu.edu.tw

Al-7

DIRECT DETERMINATION OF RESONANCE PHASE OF X-RAY REFLECTON BY
MULTIPLE DIFFRACTION

Y.P. Stetskoa.b, G.Y. Lin 3 , Y.S. Huanga, C.H. Chao 3 , Y.R. Lee, and S .-L.
Changa. b. 3 Department of Physics, National Tsing Hua University, bSynchrotron
Radiation Research Center, Hsinchu , Taiwan, R.O.C.,
X-ray diffraction/ scattering for atoms in excited states or under resonanceconditions has currently been used to probe atomic and electronic structures ofmatter. In the case of multiple diffraction at atomic absorption edges , the effects
of anomalous dispersion on multi-wave x-ray interference in crystals areinteresting and important topics to investigate. In this paper, highly phasesensitive profiles of the diffraction intensity ratios of two inversion-symmetryrelated multiple diffractions at absorption edges exhibiting strong asymmetriccharacteristics, compared with those far from the edges, are experimentally andtheoretically observed . The changing of asymmetry of these ratios results fromthe anomalous dispersion corrections in the structure factors due to thesignificant change of the resonance phase at the absorption edge. Excellent
agreement between the experimental and theoretical results is obtained. The
proposed resonance perturbation Bethe (RPB) approach allows for thedetermination of the changes of x-ray reflection phases under resonanceconditions . This provides a highly sensitive way for experimental investigation of
the spectral distribution of reflection phase shift due to the resonance.
Email : stetsko@phys.nthu.edu.tw

Al-8

X-RAY FLUORESCENCE MEASUREMENT UNDER MULTIPLE DIFFRACTION
CONDffiON

Y. R. Leea, G.G. Lina, Y.P. Stetskoa. b, S.Y. Chenga. C.C. Kuoa, Y.R. Joua, P.S.
Fanga, and S.-L. Changa. b, anepartment of Physics, National Tsing Hua
University, bSynchrotron Radiation Research Center, Hsinchu. Taiwan, R.O .C.,
Angular distribution of X-ray fluorescence under three-beam diffraction
condition is investigated using synchrotron radiation for GaAs single-crystals.
The fluorescence yield and multiply diffracted intensities as a function of the
Bragg angle and the azimuth angle of rotation of a symmetric Bragg primaryreflection are measured. It is found that fluorescence yield may first increase
and then decrease as the azimuth angle moves across the exact three-beamdiffraction position, or vice versa, depending on the polarization of the incident
beam and the triplet phases involved in the diffraction process. However, thecorresponding multiple diffraction intensities show almost opposite
characteristic to fluorescence. The relationship between fluorescence yield anddiffraction intensity is thoroughly examined. A theoretical interpretation of theobserved behavior is also given.
Email: d887306@oz.nthu.edu.tw

A2 : Instru~ne. ntation an dtec hn iqu es.

A2-1DEVELOPMENT OF A MICROSTRIP GAS COUNTER

V. Radhakrishna, K. Rajanna, S.S. Desai* and A.M. Shaikh*. Department ofInstrumentation, Indian Institute of Science, Bangalore 560012. *Solid State
Physics Division, Bhabha Atomic Research Centre , Mumbai 400 085.
Since their introduction in 1986 by Oed, microstrip gas detectors have attracted a
lot of interest in the field of gas detectors. This is due to their many promisingfeatures such as high gain, high count rate capabilities, and better spatial andenergy resolution characteristics. We report here design and development of a one
dimensional position sensitive microstrip detector. The microstrip pattern isgenerated on an insulating borosilicate glass substrate and consists of alternate
anodes and cathodes generated by deposition of chromium and photolithography
technique. The anode width is 25~-tm. cathode width 150j.lm, and separation
between them is 250j.lm with a pitch of 675~-tm. The anodes are connected at one
end by a meandering chromium resistive strip 0.1 mm in width for position
sensing using charge division technique. The effective active area of the microstrip
detector plate is 30mm x 30mm. The microstrip was tested with x-rays andneutrons using appropriate fill gases. Energy resolution of 17%(FWHM) for 5.9
keV x-rays and 12.5% for 760keV neutrons was obtained. At present a position
resolution of 900j.lm (FWHM) has been achieved with x-rays.
Email: detsspd@magnum.barc.ernet.in

A2-2

1WO-DIMENSIONAL POSmON SENSITIVE DETECTORS FOR NEU1RON AND XRAY SCA1TERING APPUCATIONS

A.M. Shaikh, S.S. Desai, A.K. Patra and J.N. Joshi, Solid State Physics Division,
Bhabha Atomic Research center, Trombay, Mumbai 400 085 , India.
Two-dimensional Position Sensitive Detectors have been developed at Trombay forsmall angle neutron and x-ray scattering work. The neutron detector is a 3 He and
Ar+C0 2 filled MWPC with charge division readout and has sensitive area of
345mm x 345mm. The detector is designed for 70% efficiency for 4A neutrons. A
prototype of this detector was .tested at different gas pressures with a wellcollimated neutron beam inclined at 90°. Excellent linearity, detection
homogeneity and spatial resolution of about 5mm x 5mm were found. To test theperformance of the detector for SANS, experiments were carried out using
standard alumina sample. Broadening of the peak and significant increase in
scattered intensity in the tail region of the profile arising from small angle neutron
scattering by alumina particles was detected. The x-ray 2-D PSD has an active
area of lOOmm x 100 mm and has been tested with Ar, Kr and Xe gases atvarious pressures. A spatial resolution of l.2mm x l.4mm and gas gain of 5xl0 4
is obtained with Ar + CH 4 (10%) gas at 300 kPa gas pressure.
Email : detsspd@magnum.barc.emet.in

A2-3

GRAZING INCIDENCE SYNCR01RON X-RAY DIFFRACTION STUDY OF MELTINGIN ULTRA-1HIN ORGANIC FILMS

Alokrnay Dattaa, Mrinmay Mukhopadhyaya, Milan Kumar Sanyala, Manabendra
Mukhe:tjeea, Thimas Geueb, Jorg Grenzerb and Ullrich Pietschb, asurface Physics
Divison, Saha Institute of Nuclear Physics , 1I AF Bidhan Nagar, Kolkata 700 064,
INDIA, and hinstitute for Physics, University Potsdam, D-14469, Potsdam,
Germany
Structural change as a function of temperature in Langmuir-Blodgett (LB) films of
cadmium salts of a long-chain fatty acid (arachidic acid) has been studied bygrazing incidence diffraction (GID) of x-rays from a synchrotron source (HASYLAB ,Germany). Films with 3, 5 , 9 and 13 monolayers (each about 25 A thick) of
cadmium arachidate (CdAr) were heated from room temperature to 100°C in an
evacuated scattering chamber and GID data collected in situ. The lattice in theplane perpendicular to the hydrocarbon chains is found to be hexagonal with adistortion in the nearest neighbor (NN) direction, to around 90°C. At 90°C an
abrupt structural change takes place. For the 3 monolayer film this is a transition
to a regular hexagon with reduced domain size. For films with more monolayers
this change causes a large reduction in the NN distortion, followed by a slower
transition to the regular hexagonal structure, at a temperature that increases
with the number of monolayers. On cooling back to 50°C the original distorted
hexagonal structure is recovered but the domain size remains small. Bragg Rod
scans for all samples show a correlation length of about 3 monolayers along thehydrocarbon chains . Structures are found to be unaffected by synchrotron
radiation. The motivation of this study is to understand the transition from twodimensional to three-dimensional melting as the number of monolayers increases.
X-ray reflectivity data has also been collected using a rotating-anode source andthe BESSY synchrotron source, to understand the structural change in thegrowth direction as a function of temperature.
Email : alok@hp l.saha.ernet..in

A2-4

SUB-SECONDANALYSIS.

X-RAY

DIFFRACTION

MEASUREMENTAND

S1RUCTURE

H. Uekusaa, Y. Ohashia, A. Ochib, and T. Tanimoric, aoepartment of Chemistry
and Materials Science, Tokyo Institute of Technology, Japan, bOepartment of
Physics, Kobe University, Japan, coepartment of Physics, Kyoto University,
Japan.
Rapid X-ray diffraction measurement technique is an essential to realize the timeresolved observations of crystalline-state reactions. unstable species in excitedstate and reaction intermediates. To achieve time resolution of seconds or sub
seconds order, the use of photon counting type two-dimensional detector isrequired.
Recently, MSGC (Micro Strip Gas Chamber) was developed for the rapid X-ray
data collection. MSGC is a gaseous detector having both photon counting andtwo-dimensional imaging properties. The features of the detector are a large
detective area of 10 x 10cm, a fine positional resolution of 100 micrometer and an
excellent capability for high counting rate up to 107 cps suitable for thesynchrotron radiation experiments .
With the measurement system consists of a MSGC detector, one axis goniometerand a laboratory X-ray generator, complete data set from typical organic crystals
were recorded within several minutes to seconds range and the results ofstructure analyses were satisfactory. In the experiment using the synchrotron
radiation at SPring-8, structure analysis of sub-second diffraction data was
successfully achieved. For an application of monitoring the diffraction pattern.
the timing resolution of sub-second can be achieved to observe the change of celldimensions caused by the excited molecules in the crystal.
Email: uekusa@cms.titech.ac.jp

A2-5

ELECTRICAL CONDUCTANCE MEASUREMENT 1HROUGH ErSi2 NANOWIREUSING DOUBLE-PROBE SCANNING IDNNELING MICROSCOPY
H. Tanakaa, Y. Shingayaa, T. Nakayamaab, and M. Aonoabc. asurface and Interface

Lab., RIKEN, Saitama, 351-0198, Japan., bJapan Science and Technology
Corporation, Saitama, 332-0012, Japan, and cosaka Univ., Osaka, 565-0871,
Japan.
We have constructed a multi-probe scanning tunneling microscope (MP-STM)
which would be a novel technique to develop future nanoscale devices. In thiswork we apply the MP-STM for the direct measurement of the conductance of onedimensional (1D) nanostructures. We prepare ErSi2 nanowires that are selfassembled on the Si (001) clean surface. ErSi 2 nanowires run along a <110> axisof the Si(001) substrate, having sizes of 1-5nm, 1-2nm and <1000nm, in width,height, and length, respectively. To investigate crystallographic and electric
properties of such crystalline ErSi 2 nanowires, we use a double-probe scanningtunneling microscopy (DP-STM) as a 'nano-tester'. DP-STM measurements showthat ErSi 2 nanowires are 1D metal conductors judging from the following
experimental results . The current-voltage curves, which are measured on a single
ErSi2 nanowire, always show linear dependence. And the resistance of ErSi 2
nanowires is proportional to their length. Interestingly, the resistance per unit
length is 1.2 MQ / nm along the ErSi 2 nanowire, being 4-5 orders of magnitudelarger than the resistance expected from the known resistivity of bulk ErSi 2. Oneof the reasons for such a high resistance may be due to an elastically-elongatedlattice spacing along the ErSi2 nanowire as a result of lattice mismatch between
the ErSi2 and Si(001) substrate* .
*Yang Chen, Douglas A. A. Ohlberg, Gilberta Medeiros-Ribeiro, Y. Austin Chang
and R. Stanley Williams, Appl. Phys. Lett., 76 (2000) 4004 .

Email : tanaka@postman.riken.go.jp

A2-6

RECENT DEVEWPMENT OF INELASTIC X-RAY SCATIERING SPECTROMETER
AND in-situ MBE DIFFRACTOMETERATBL-ll:XU IN SPring-S

J. Mizuki, Synchrotron Radiation Research Center, Japan Atomic Energy
Research Institute (JAERI) and Core Research for Evolutional Science andTechnology (CREST)

We will present here two new spectrometers installed at JAERI beamline in
SPring-8, which are an Inelastic X-ray Scattering (IXS) spectrometer and anotherin-situ MBE diffractometer. Particularly IXS experiments have been stimulated by
the high brilliance synchrotron radiation sources, so called Third Generation
Sources. In comparison with neutrons, X-rays can interact directly with electrons.
This makes IXS possible to investigate the nature of excited electron states inenergy-momentum space , which are the essential information in condensed
matter physics. The IXS spectrometer designed has 0 . 1 eV energy resolution and0-30 eV energy transfer with 6-10 keV incident X-ray energies.
We have also installed an in-situ MBE diffractometer for studying layer-by-layer
crystal growth especially focused on III-V semiconductors and related materials at
our beamline. This diffractometer allows us to investigate dynamic growth process
as well as elaborate crystallography.
The orbital excitation spectrum on manganites taken by IXS and the preliminary
data on GaA~ growth will be shown in the talk.
Email : mizuki@spring8.or.jp

A2-7
A LARGE SIZE SOLID-STATE DETECTOR FOR PROTEIN CRYSTALLOGRAPHY

J. Hendrix X-Ray Research GmbH, Segeberger Chaussee 34, 22850 Norderstedt,
Germany

A fully solid-state detector inaugurating the post-CCD era will be described.
The fully solid-state detector is based on the direct conversion of the absorbed Xrays into electric charges. The charges follow electric field lines in thephotoconductor. This direct conversion makes the use of phosphors and opticalelements (e .g. fibre optic tapers) obsolete. Consequently, the spatial resolution isextremely high. The point-spread function is well within 1 pixel. Measurements
have shown that the reflection spot sizes and separation depend solely on thesource size, beam size, crystal size and the beam divergence.
The size of the present detector is 35 em x 43 em , or 2560 x 3072 pixels of 140(J1II1) 2 . Thus , in addition to the excellent spatial resolution, the system has theadvantage of an untiled large size. The readout time of the whole area will be one
second. The combination of high spatial resolution, large size and fast readout
makes this system a first choice for the most demanding applications at the 3rct
generation synchrotron sources. Due to the high resolution, reflections occupy a
low number of pixels. The favorable influence on the signal to noise ratio will be
discussed.
Crystallographic data collected at 3rct generation synchrotron sources will beshown and discussed.
Email: jules@marresearch.com

A2-8

ROTATIONAL MOTIONS IN SOLIDS: QUASIELASTIC NEUTRON SCATTERINGS'IUDY

S. Mitra and R. Mukhopadhyay, Solid State Physics Division, Bhabha Atomic
Research Centre, Mumbai 400 085, India.
Quasielastic neutron scattering (QENS) technique has been successfully used toelucidate the molecular motions and physical properties related to it. in variety ofsystems. Thermal neutron is a powerful probe to study the dynamics incondensed matter for its matching energy with the excitations of the solid.
Further systems containing protons are more suitable for its large scatteringcross-section. Periodic motions give rise to characteristic frequency in the
spectrum whereas the random motion leads to Doppler broadening of thescattered neutrons, which result in the broadening of the elastic line known asquasielastic broadening. QENS is a unique technique provides information on thetime scale of the motion as well as the geometry of the motions . In this paper, weshall discuss some of the systems studied using the facility available at Dhruva,
Trombay and other mega-facilities, with particular emphasis on reorientationalmotion of pyridinium ion in pyridinium iodide, reorientaional motions of different
units of a liquid crystal at different phases, alkyl chain motions in monolayer
protected metal clusters, molecular motions in polymeric systems and in confined
media like different zeolites etc.

Email: mukhop@apsara.barc.emet.in

A2-9

NEW GENERATIONQUANTITATIVE X-RAY MICROSCOPY FOR MATERIALSSCIENCE AND OTIIER APPLICATIONS.

S.W. Wilkinsa, S.C. Mayoa, T.E. Gureyeva· , P.R. Millera, A. Poganya, A. W.
Stevensona. D. Gaoa, D. Paganina.b , T.J Davisa and D. J. Parrya, acsiRO ,Manufacturing Science & Technology, PB33 Clayton Sth MDC. Vic 3169. bSchoolof Physics, University of Melbourne, Parkville , Vic 3052.
We briefly outline a new approach to X-ray ultramicroscopy using projection
imaging in a scanning electron microscope (SEM) 1 . Compared to earlier
approaches (see e.g. Refs 2 -4). the new approach offers spatial resolution of :::::0.1
micron and includes novel features such as : i) phase contrast to give additional
sample information over a wide energy range , ii) rapid phase/amplitude extraction
algorithms to enable new real-time modes of microscopic imaging5-8 widespread
applications are envisaged to fields such as materials science, biomedical
research, and microelectronics device inspection. Some illustrative examples arepresented. The quantitative methods described here are also very relevant to Xray projection microscopy using synchrotron sources. Studies of bio materials,
microelectronic devices, natural fibres and a number of other materials will bepresented.
References
1. S.W. Wilkins, High resolution X-ray imaging of very small objects, PCT Pat.
Applicn. PCT/Au/98/00237 (April 1998).
2. J. Kirz, C. Jacobsen & M : Howells, Q . Rev. ofBiophys., 28(1) 33-130 (1995).
3. H.C. Chapman, & D. Sayre, Acta Cryst. A51. 237-52 (1995).
4 . Proceedings of X-Ray Microscopy IV, eds. V.V. Aristov & A.I. Erko (Institute ofMicroelectronics Technology, Chernogolovka, Russia 1994) .
5. K.A. Nugent, T.E. Gureyev, D.J . Cookson, D. Paganin, Z. Barnea, Phys. Rev.
Lett. 77, 2961-4 (1996) .
6. T.E. Gureyev, and S .W. Wilkins, J . Opt. Soc .. Arn. Al5, 579-85, (1998).
7. T.E. Gureyev. and S.W. Wilkins, Optics Communs; 147, 229-32 (1998).
8 . T.E. Gureyev, S .C. Mayo, S.W. Wilkins, D. Paganin, and A.W. Stevenson, 86,
5827-30, 2001.
Email : wilkins@cmst.csiro.auA2-10IMAGING PlATE WEISSENBERG CAMERA AT 1HE BL04B2 BEAMLINE OFSPRING-8 AND ITS APPUCATION TO 1HE STRUCTURE DETERMINATION OF
POLYOXOTUNGSTATE CRYSTALS

Tomoji Ozeki.*,a Katsuhiro Kusaka,b Noritaka Honma, a Yuji Nakamura,a Setsuko
Nakamura.a Shunsuke Oike,a Nobuhiro Yasuda,a Hiroyuki Imura,a Hidehiro
Uekusa.a Maiko lsshiki, c Chuji Katayama,d and Yuji Ohashi,a. b. aoepartment ofChemistry and Materials Science, Tokyo Institute of Technology and bCore
Research for Evolutional Science and Technology, Japan Science and Technology
Corporation. 2-12-1 0-okayama, Meguro-ku, Tokyo 152-8551, Japan, CJapan
Synchrotron Radiation Research Institute, 1-1-1 Kouto, Mikazuki-cho. Hyogo
679-5198 , Japan, and dMAC Science Co ., Ltd ., 1-5-1 Shin-yokohama. Kouhokuku, Yokohama 222-0033, Japan
An imaging plate Weissenberg camera has been installed into the BL04B2
beamline of SPring-S in order to provide a facility for single crystal structure
analyses of small molecules . This camera is equipped with a cylindrical imaging
plate and an integrated imaging plate reader, allowing fully automatic datacollection. Obtained diffraction images are automatically processed using the
program DENZO. As the beamline is designed for providing a high-flux. highly
focused and high-energy (> 37.78 keV) X-ray beam, this camera is ideal for
performing absorption-free diffraction experiments for heavily X-ray absorbing
crystals . Note that most elements show the absorption coefficients for the 37 .78
The
keV X-ray less than the seventh of those for the MoKa radiation.
performance of this instrument has been exemplified by an analysis of the crystal
structure of [(n-C 4 H 9 ) 4 N]z[W6 0 19 ) . Its absorption coefficients for 37.78 keV X-ray
is 1.91 mm-1 while it is 14.3 mm- 1 for MoKa radiation. The structure analysis led
to precise positional parameters and well-behaved displacement parameters not
only for heavy atoms but also for light atoms. Also, final residual electron
densities were -1.85 to 2.20 eA-3, although an asymmetric unit contains six
independent W atoms. Other examples will also be discussed.

Email : tozeki@cms. titech.ac.jp

A2-llSINGLE-CRYSTAL NEU1RON DIFFRACTION AT ANSTO.

Wim T. Klooster, Physics Division, Australian Nuclear Science & Technology
Organisation, Menai NSW 2234, Australia.
The current and future single-crystal neutron diffraction capabilities at ANSTO
will be presented. At HIFAR there is currently a 4-circle diffractometer. The
Replacement Research Reactor (RRR) will come online in 2005. At a workshop
December 11-12, 2001, at ANSTO, the main goal will be to determine what type ofsingle-crystal diffractometer will be developed for RRR, and what should be thespecifications. The choice will be between a 4-circle diffractometer and a quasiLaue type diffractometer.
Email : wim@ansto.gov.au

A2-12
RECENT PROGRESS OF A CRYSTAL AND MAGNETIC STRUCTURE ANALYSIS BY
USING A SINGLE CRYSTAL NEUTRON DIFFRACTOMETER FONDER

Y. Noda, H. Kimura, M. Watanabe, R. Kiyanagi, Y. Fukuda, S. Kamiyama, and S .
Maesaki, Institute of Multidisciplinary Research for Advanced Materials, Tohoku
University, 2-1-l Katahira, Aoba-ku, Sendai 980-8577 , JAPANVery recently, we have developed a 4-circle diffractometer FONDER (Four-Circle
Off-center Type Neutron Diffractometer) for a single crystal experiment as well asa horizontally and vertically bend monochromator with silicon (422) ·plates, at theguide-hall of the reactor JRR3M-JAERI (Japanese Research Reactor) at Tokai.
Wavelength of the neutron is l.57A and the maximum scattering angle of asample is 156 degree. As a test sample, we studied crystal and magnetic
structures of manganese fluoride MnF2. The crystal size is 2.5 x 2 .5 x 2.5 mm 3 .
Good R-factor was obtained: R=l.77% (at 80K >TN) and R=l.90% (at 7K <TN) for
Concerning the magnetic structure, additional magnetic
crystal structures.
parameters S. g and B(3d-electron) were obtained with R=3.39%. The electron
density, which is carrying spins, was obtained. We also investigated severalhydrogen bond materials like squaric acid (C 4 0 4 H 2). MeHPLN (C 14 02H 14 • 5methyl-9hydroxyphenalenone). and the characteristic feature of hydrogen atom is?bserved. Other examples such like (NH 4 )PtC1 6 will be also shown.
Email : ynoda@tagen. tohoku.ac.jp

A 3 : C ry st al lo gr ap hy in ph ys ic s
an d ea rt h sc ie nc es

A3-1

IDGH PRESSURE AND IDGH TEMPERATURE STUDIES OF LiYF4 AND LiYbF4
A. Sen, S. L. Chaplot and R. Mittal, Solid State Physics Division, Bhabha Atomic

Research Centre, Trombay, Mumbai 400 085
Remarkably low lasing thresholds in the rare earth (e.g. Nd3+, Er3+or. U3+) doped
tetragonal fluoroscheelites , LiYF4 and LiYbF4 , mainly because of their superior
thermal and optical properties , cater to several optical domains of application,
primal to which is the wide range (UV-IR) thermally tunable solid state lasers withastoundingly high efficiency. As an extension of the bountiful works done over theyears on these complex crystals, we report here the lattice dynamical calculationsof the pressure as well as temperature dependence on their structures andproperties (optical and thermodynamic) . Our computations, based on a rigid ion
model, suggest that the observed phase transition in LiYF4 , at a pressure of 7
GPa may be initiated due to a dynamical instability of a transverse acoustic
phonon mode at a small wave vector along the [1 3 0) direction. For LiYbF4 , ourpredicted value is 6 GPa. We calculated the volume compressibility for LiYF4 as
14.4 x lQ-3 GPa- 1 • which is in congruence with the experimental value of 12.5 x
l0-3 GPa-1 . The linear compressibilities for lattice lattice parameters a and c of
LiYF4 are predicted by our model as 6.0 x lQ-3 GPa- 1 and 2.3 x lQ-3 GPa- 1 against
5.4 x lQ-3 GPa-1and 2.6 x lQ-3 GPa-1 of LiYbF4 .0ur model further suggests theaverage Gruneisen parameter for zone center phonon modes of LiYF4 and LiYbF4
as 1.12 and 1.09 respectively. The same potential model would be used inmolecular dynamics simulations for a microscopic understanding of the possible
phase transitions at the atomic level.
Email: asen_2121n@yahoo.co.uk

A3-2

POWDER DIFFRACTION AT MEGABAR PRESSURES:

ANALYSIS

OF TilE

lATTICE S1RAINS

Anil K. Singh, Materials Science Division, National Aerospace Laboratories,
Barrgalore 560 017, India.
The diamond anvil cells (DACs) have been used to record x-ray diffraction
patterns from the samples compressed to a few hundred gigapascals. Over theyears such -@-x periments have provided valuable information on equation of stateand pressure-induced phase transitions in solids. A well-characterised stressstate (ideally hydrostatic pressure) of the sample is essential for a rigorous
interpretation of the diffraction data. However, the stress state of the sample
compressed in a DAC tends to become nonhydrostatic, especially when thepressure exceeds -50 GPa. The modelling of the actual stress state of the sample
and its effect on the measured lattice strains has led to a considerable
understanding of this subject. The presence of nonhydrostatic stress component
is no longer considered undesirable. On the other hand, it has now become
possible to analyse the peak-position data to derive the volume compression data
corresponding to equivalent hydrostatic pressures and the shear strength, as afunction of pressure, of the sample material. Of particular interest is thepossibility of determining the single-crystal elastic moduli as a function ofpressure. More recent work has shown that additional information becomes
available from the analysis of the diffraction line widths.
Email : aksingh@css .cmmacs.emet.in

A3-3

S1UDY OF ANTI-COMPTON SCATTERING FROM BORIC ACID POWDER

B. Mallicka, T. PateP and R.C. Beherab, aoepartment of Physics, hDepartment ofMetallurgical Engineering, Regional Engineering College, Rourkela - 769 008,
India.
When the momentum of x-ray quantum becomes comparable to or larger thanmOe (mo is the rest mass of electron and c is the velocity of light), the momentumof the photon gets modified. This is known as the quantum mechanical effect. It isquite logical to think that anti-Compton effect occurs from collision of Compton
ejected electron and other photons of the incident x-ray beam. We reported an
observation of anti-Compton scattering from polyethy~ene terepthalate and lowdensity polyethylene in a separate paper with its relevant quantum mechanicalderivation. Boric acid powder (H 3 B0 3 ) of 99.5% purity was compressed in a die toform a flat-faced sample of 60x23x5 mm3 size. The experimental set up used by
us for spectroscopic analysis of the diffuse anti-Compton scattering was a Philips
analytical x-ray instrument having bent graphite crystal monochromator
employing Bragg-Brentano parafocusing optics in reflection-reflection mode. CuKa
(l.54056A) radiation of incident line beam from a high power ceramic tube wasused for this study. Wavelengths of Compton and anti-Compton modified
scattered radiation at 1100 were calculated to be 1.56938A and 1. 517 49A
respectively and the corresponding wavelengths at 1200 were also estimated to bel.57841A and l.50760A respectively. Ratio of the intensities (anti-Compton/
unmodified) at 1100 and 1200 were found out to be 1.0242 and 1.1218
respectively. The above ratio goes on increasing with scattering angle as inCompton scattering. For these scattering angles the total scattering cross-section
for anti-Compton photon were computed as 6.55361 (10-25 cm 2/ electron and6.59349 ( 10-25 cm2 /electron respectively. The above data leads us to believe thatanti-Compton scattering does exist. Quantum mechanical expression and detailsof this discovery will be presented.

Email : rcbehera@rec.ori.nic.in

A3-4

EXPERIMENTAL. STUDIES OF PHASE 1RANSffiONS IN AB0 3 PEROVSKITES

Brendan J. Kennedya and Christopher J. Howardb , a School of Chemistry, The
University of Sydney, Sydney NSW 2006 Australia and bANSTO, Private Mail Bag
l, Menai NSW 2234 Australia.
The structural variants of AB0 3 perovskites and the phase transitions between
them have long been fascinating in chemistry. physics and the earth sciences.
This interest has been further fuelled by the remarkable properties displayed byperovskites and related oxides near structural instabilities, including colossal
magneto-resistance, superconductivity and ferroelectricity. The cubic perovskite
is a simple but demanding structure, having only one variable , the lattice
parameter. Numerous perovskites have lower symmetry structures that involve
tilting of the B0 6 octahedra. Considering only tilting of the B0 6 octahedra, grouptheory provides a method by which sequences of phase transitions can bepredicted. In the present paper we will describe some of our recent variabletemperature experimental powder neutron and synchrotron X-ray diffraction
studies of a number of "simple" perovskite systems including SrM0 3 M = Ru , Hf
and Zr and some substituted analogues including Sr 1 _xBaxZr0 3 and La 1 _xSrxCrl xTix03. The systems studied display an array of room temperature structures
ranging from orthorhombic through rhombohedral, tetragonal to cubic.
Transitions between these variants are observed. The paper will demonstrate thepredictive ability of the group theory analysis and highlight the advantages of both
high resolution and fine temperature intervals in unravelling the detail of phasetransitions.
Email: b.kennedy@chem.usyd.edu.au

A3-5

CRYSTAL S'IRUCTIJRE AND EXCHANGE INTERACTIONS IN A DOUBLE CHAINSSYSTEM NH4 CuC13

Budhy Kurniawan, Department of Physics, Faculty of Mathematic and Sciences,
University of Indonesia, Depok 16424, Indonesia.
NH 4 CuC13 crystallizes in a monoclinic structure and belongs to KCuC1 3 family.
The space group of this compound is P2Ifc and the crystal structure comprises
double chains of edge sharing CuC1 6 octahedral along the a-axis. The Jahn-Teller
effect distorts all of the octahedral. The elongated axes of the octahedral arealigned in the same direction. For the be-plane, the double chains are located at
the comers and center of the unit cell and separated by NH 4 + ions. The lattice
parameters of NH 4 CuC13 are: a= 4.066 A. b=l4.189 A and c=9 .003 A with~= 97°
30'. Due to the crystal structure, it is considered that the exchange interaction in
the double chains are described by the spin ladder with diagonal interaction or
the alternating chain with the next nearest neighbor interaction. Configuration of
the hole orbital d(x2-y2) of the Cu 2 + ions on their sites give a suggestion that theexchange interactions J 2 and J 3 are both antiferromagnetic. The nature of J 1interaction is not clear from the crystal structure. The values of the exchangeinteraction constants in NH 4 CuC1 3 are presently not known. From the chemical
viewpoint, NH 4 CuC13 seems to be described as a spin 1/2 alternating Heisenberg
chain consisting J 2 and J 3 interactions with the next nearest neighbor interaction
J 1 . Thus the remarkable quantum effect characteristic of the spin ladder oralternating chain is expected in the present system.
Email : bkuru@fisika.ui.ac.id

A3-6
lllGH 1EMPERATURE PHASE 1RANSmONS IN TUNGS1EN 'IRIOXIDE

Christopher J Howard 1 , Victor Lucal and Kevin S Knight2 , 1Australian Nuclear
Science and Technology Organisation, Private Mail Bag 1, Menai, NSW 2234,
Australia, 2 ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot,
Oxfordshire OX11 OQX, UK.
Seventy years have elapsed since the first crystal structure determination intungsten trioxide, W0 3 , and studies of its high temperature phase transitions
were in vogue almost fifty years ago. The material is of technological interest, forexample, as the preferred active component in electrochromic windows. Despite a
protracted effort, including several significant studies published as recently as
1999, there has been until now a measure of uncertainty about the structures of
the high temperature phases and the nature of the transitions occurring.
We have undertaken neutron powder diffraction measurements on W0 3 , in finetemperature steps from room temperature to 1000 °C, using the High Resolution
Powder Diffractometer (HRPD) at the ISIS facility, UK. HRPD is currently thehighest resolution neutron powder diffractometer in the world. By inspection andanalyses of the very high quality neutron data, and making reference to theresults from .a group theoretical analysis, we discovered and identified a new hightemperature monoclinic phase existing over a narrow temperature range , andconfirmed one of two models proposed previously for the orthorhombic structure .
We present for the first time a complete and correct account of the hightemperature phases in perovskite-like wo3 and of the transitions occurring
between them.
Email : cjh@ansto.gov.au

.A3-7SINGLE CRYSTAL EPR STUDIES ON Mn(ll)IN SARCOSINE CADMIUMCHLORIDE/BROMIDE : STUDY OF ZERO FIELD SPLITTING TENSOR IN
ISOSTRUCTURAL COMPLEXES.

D.Pathinettam Padiyana and C.Muthukrishnanb , aoepartment of Physics,
Manonmaniam Sundaranar University, Tirunelveli - 627 012, India andbDepartment of Physics, A.K.G.S. Arts College, Srivaikuntam- 628 8 19 , India.
Single crystal EPR spectra of Mn(II) doped sarcosine cadmium chloride (SCC) andsarcosine cadmium bromide (SCB) are studied at room temperature. Single
crystals of SCC and SCB are grown by slow evaporation technique using
sarcosine and cadmium cloride I cadmium bromide in stoichiometriccomposition. sec crystallizes in the monoclinic system with four formula units inthe unit cell. Preliminary X-ray measurements indicate that SCC and SCB are
iso-structures. EPR spectra are recorded in Q-band and in X-band for SCC and
SCB respectively. 1\vo magnetically inequivalent sites are observed in both thelattices. The spin Hamiltonian parameters are extracted from standard procedureand found to have rhombic symmetry. The angular variations have been
simulated using the values of a, D ane E by second order perturbation theory. The
values are a=10x1Q-4cm-l, D=480x1Q-4cm-l, E=-115x1Q-4cm-l for Mn(II)/SCC
and are a= 10x10-4cm- 1 , D=460x1Q-4cm- l, E=-98xlQ-4cm-l for Mn(II)/SCB. The
observed large value · of zero field tensor is due to the steric effects of the crystal
packing caused by the ligand. Relative signs of A and D are evaluated fromsecond order effects. Matamura's plot predicts an average covalency of 8.8 % and7 .7% for the manganese-ligand bond and it is in reasonable agreement with thevalues reported for the manganese-oxygen bond.
Email: bio@md3.vsnl.net.in

A3-8

AN ALTERNATIVE APPROACH TO 1HE MA1RIX CORRECTION PROCEDURE IN
QUANTITATIVE X-RAY POWDER DIFFRACTION STIJDIES OF SAMPLES IN MICA
- KAOLINITE - QUAR'IZ SYSTEM.

O.K. Sen, Mineral Physics Laboratory, Geological Survey of India, Kolkata 700016.
Matrix effect correction in the quantitative X-ray powder diffraction ofmulticomponent earth samples is a problem difficult to tackle both by internal
standard method and standardless methods . Behavioural pattern of the matrix
effect in the tertiary system of Mica - kaolinite - quartz has been investigatedusing a mixing scheme in which presence of one of the phases has been gradually
increased within a matrix of the other two relative proportions of which also got
changed in the process. Three such sampling models were used to collect data.
XRD tested pure sample of each of the phases were used to prepare the samples
X-ray
followed by a weighing scheme using a Perkin-Elmer microbalance.
diffraction data were collected using APD-1700 system in conjunction with PCAPD software from M/s. Philips, Holland. Quantitative data in counts per
step/time were collected against d(002). d(001) & d(ll2) spacings for mica,kaolinite and quartz respectively. It is observed that the variation of mica andkaolinite within a varying matrix of kaolinite - quartz & mica - quartz respectively
show a definite patterns whereas variation of quartz within a varying matrix ofmica - kaolinite is irregular and unpredicatable within the percentage ranges
examined . Estimation of the wt. percentages of the three phases present in
unknown samples of this type of clay like tertiary system is possible using the twoformer variation patterns with reasonably fair consistency with an added
advantage of mutual cross checking.

Email : gsihqlab @ vsnl.net

RESONANT FORBIDDEN REFLECTIONS FROM GERMANIUM

Jun KOKUBUNl, Kohtaro ISHIDAl and Vladimir E . DMITRIENK02, 1Faculty of
Science and Technology, Tokyo University of Science, Noda, Chiba 278-8510,
Japan, 2A. V. Shubnikov Institute of Crystallography, 117333 , Moscow, Russia
Forbidden reflections, excited owing to anisotropic environment of atoms, arereferred to as ATS (anisotropic tensor of susceptibility) reflections. Most of the ATS
scattering observed up to now can be explained by dipole transitions. However,
unexpected phenomena from dipole approximation were reported in some cases ,which may be explained by higher order approximation.[1, 2] In the dipole
approximation, ATS scattering cannot be excited from aGe crystal because of its
high symmetry. Therefore, the ATS reflection from Ge was presumed to originate
in dipole-quadrupole transition.[3] However, if the thermal motion of the atoms istaken into account, the ATS scattering can be observed even in the dipole
approximation.[4] In the present work, we investigated the Ge 006 forbidden
reflection near the Ge K-absorption edge using synchrotron radiation in Tsukuba.
We observed one peak in the energy spectrum just near the edge. At the peak
position the azimuthal angle dependence agrees with a calculation b'ased on the
dipole-quadrupole transition. However, we cannot determine the origin, whether it
is due to the dipole-quadrupole transition or the thermal motion, because theazimuthal dependence shows the same profile in both cases. Therefore wemeasured the temperature dependence of the reflection. From room temperature
to 30 K the intensity decreases to be about a quarter. This result indicates thatthe forbidden reflection is mainly due to the TMI (thermal-motion-induced) ATS
scattering.[5][1] K. D . Finkelstein, Q. Shen and S. Shastri: Phys. Rev. Lett. 69 (1992) 1612.
[2] J. Kokubun et al.: J. Phys. Soc. Jpn. 67 (1998) 3114; PF Act. Rep. 16 B (1998)
13.
[3] D. H. Templeton and L. K. Templeton: Phys. Rev. B49 (1994) 14850.
[4] V. E. Dmitrienko, E . N. Ovchinnikova and K. Ishida: JEPT letters 69 (1999)
938.
[5] J . Kokubun et al.: Phys. Rev. B 64 (2001) 073203; PF Act. Rep. 17 B (1999) 15.
Email: kokubun@ph.noda.sut.ac.jp

A3- 10

NEW MODIFICATION OF PYRRHOTITE FOUND IN IN1ERPLANETARY DUSTPARTICLES (IDPs)

K.Ohsumia and M. E . Zolenskyb, aMaterials Structure Science, Oho 1-1, Tsukuba,lbaraki, 305 -0801 Japan, and bNASA, J ohnson Space Center, Houston, Texas.
USA.
Iron-nickel sulfides are the key minerals to understand the early solar system
history, because they are the only phases present in all types of extraterrestrial
materials.
All the diffraction experiments were carried out at the BL-4B 1 of the Photon
Factory, KEK, by using diffraction equ ipment developed for a micrometer-sized
specimen and a micro-area of a larger sample .
The chemical formu la of the sample (IDPs: L2005 AG 17) was determined to be
Feo.s 3 S by EPMA. Oscillation patterns were taken by monochromatic synchrotron
radiation, and all of the diffraction spots can be well indexed based on the 3C typepyrrhotite. Four week, but distinct, powder lines are also observed in all
oscillation patterns ; these lines correspon d to those of magnetite (Fe 3 0 4 ).
According to the chemical composition of present sample and the existence ofm agnetite in the same sample, the crystal structure of the present 3C type must
be different from that reported previously having a chemical formula of Fe 0 .875 S.
The structure was analyzed based on 'extraordinary conditions of missing
reflections' . From the obtained structu re, the chemical formu la of the present 3Ctype is represented as Fe 0 .5 S. This type of modification is entirely new a nd hashnot been known before either n a tural or synthetic.
The structure exhibits theenhancement of symmetry'.

phenomena

Email : kazumasa.ohsumi@kek.jp

of'homometry'and'diffraction

REFINEMENT OF CRYSTAL STRUCTURAL PARAMETERS AND
DENSTIY USING CONVERGENT-BEAM ELECTRON DIFFRACTION

CHARGE

M. Tanaka and K. Tsuda, Institute of Multidisciplinary Research For Advanced
Materials, Tohoku University, Sendai 980-8577, JAPANWe developed a new method to refine crystal structural parameters using
convergent-beam electron diffraction (CBED). which is applicable to nanometersize crystal structure analysis (K. Tsuda and M. Tanaka: Acta Cryst. A55, (1999)
939). The method is based on the fitting between theoretical calculations andexperimental intensities of energy-filtered tUXJ-dimensional CBED patterns
containing zeroth-order Laue-zone (ZOLZ) and higher-order Laue-zone (HOLZ)
reflections.
The use of HOLZ reflections is essential for the present method
because small displacements of atoms can be sensitively detected using HOLZ
reflections with large reciprocal vectors.
For this purpose, we developed anenergy-filter transmission electron microscope (JEM-2010FEF) and an analysis
program (MBFIT) to refine structural paraineters based on the dynamicaldiffraction theory.
Using this method, we have refmed the atom positions and anisotropic DebyeWaller factors of the high-temperature phase of LaCr0 3 . Clear anisotropy of thethermal vibration of the oxygen atoms has been successfully detected by electron
diffraction for the first time . The low-order structure factors, which are sensitive
to valence electrons, were refined together with these structural parameters, andwere converted to deformation charge density. The result clearly shows chargetransfer from La and Cr atoms to 0 atoms .

Email: tanakam@tagen.tohoku.ac.jp

A3-12

IllGH-PRESSURE
POLYMORPHS

lATTICEDYNAMICAL

STIJDIES

OF

THE

Al2Si05

Mala N. Rao, S.L. Chaplot and N. Choudhury. Solid State Physics Division,
Bhabha Atomic Research Centre, Mumbai - 400085.
The AI 2 Si0 5 polymorphs, sillimanite, andalusite and kyanite, are important hightemperature ceramic materials as well as geophysically important minerals .
Sillimanite and andalusite are orthorhombic, while kyanite is triclinic. These
polymorphs are structurally complex and have two distinct types of AI atoms, with
one type being in octahedral coordination in all of them. The other aluminium
atom is in four. five and six -coordination respectively in sillimanite, andalusite
Earlier we had
and kyanite. The silicon atom is in tetrahedral coordination.
undertaken lattice dynamics shell model calculations and inelastic neutron
scattering experiments to de.termine the phonon density of states (Rao et al.
(1999) Phys. Rev. B60, 12061). We now report calculations of the high pressure
structure and thermal properties of these minerals. The computed high-pressure
crystal structure, equation of state, phonon properties, mean squared atomic
displacements and specific heat of the AI 2 Si0 5 polymorphs are found to be ingood agreement with available experimental data. The model can be fruitfully
used to explore the possible existence of new phases.
Email : tassspd@apsara.barc.emet.in

A3-13lllGH PRESSURE LAJ'TICE DYNAMICS OF 1HE Si~4 POLYMORPHS

N. Choudhury and S. L. Chaplot. Solid State Physics Division, Bhabha Atomic
Research Centre, Mumbai 400 085, India.
Silicon nitride Si3 N4 is an important ceramic material finding numerous
applications. Recently, a new cubic spinel polymorph of Si3 N4 synthesized underhigh pressure-temperature conditions has been identified; this phase is harderthan the known a and f3 phases, making it a likely candidate for several
important applications. While all the silicon atoms are in tetrahedral coordinationin the <X and f3 phases, two-thirds of the silicon atoms are in octahedral
coordination in the spinel phase. To understand how the changes in siliconcoordination manifest in the vibrational and thermodynamic properties, wehave undertaken detailed lattice dynamics calculations of <X, f3 and cubic Si 3 N4 .
The calculated crystal structures, bulk moduli,
neutron-weighted density ofstates, specific heat, thermal parameters and equation of state are found to be ingood agreement with available data. The compressibility and phonon density ofstates in the cubic phase are significantly different from that in the <X and f3 phases . These differences
arise from the changes in silicon coordinationaccompanying the transitions .
Email: dynamics@apsara. barc.emet. inA3-14EQUATION OF STATE AND THERMODYNAMIC PROPERTIES OF BaFCL
R. Mittal, S. L. Chaplot, A. Sen, S. N. Achary+ and A. K. Tyagi+, Solid State
Physics Division (+Applied chemistry Division), Bhabha Atomic Research Centre,
Trombay, Mumbai 400 085

The matlockite structured compounds (e.g. BaFCl} are of technologicalimportance by virtue of their image storage properties on dilute-doping with rareearth ions. The structure of BaFCl (body centered tetragonal, space groupP4nmm, Z=2) consists of alternate sheets of BaF2 and BaCl2 . We have developed
a rigid ion model for the study of the structure, dynamics and thermodynamic
properties of this material. The model has been validated by phonon density ofstates measurements from polycrystalline sample of BaFCl by the technique of
inelastic neutron scattering at the Dhruva reactor. The calculated crystal
structure, equation of state, thermal expansion and temperature factors are ingood agreement with available experimental data. The calculated bulk modulus of
43.3 GPa is . in good agreement with the experimental value of 44 ± 5 GPa. Thesestud~es have enabled a microscopic understanding of the thermodynamic
properties of BaFCl.
Email: rmittal@apsara.barc.emet.in

A3-15DISCOVERY OF AN ANTIFERROELEC1RIC PHASE TRANSmON IN Sr0 .70
Cao. 30Ti03 : X- RAY, DIELEC1RIC AND RAMAN STIJDIES

Rajeev Ranjan, Sanjay Kumar Mishra and Dhananjai Pandey, School of Materials
Science and Technology, Institute of Technology, Banaras Hindu University,
Varanasi- 221005, India. and R.Ouillon, J.-P. Pinan- Lucarre, P. Ranson and Ph.
Pruzan , Physique des milieux condenses, UMR 7602,Universite Pierre et Marie
CURIE, B77, 4 Place Jussieu, 75252 PARIS Cedex 05, France
We show that Sr 1_x CaxTi0 3 (SCT) undergoes an antiferroelectric (AFE) phasetransition in the composition range 0.18:o;x :::; 0.40 [Ranjan et al Phys. Rev. Lett.
84, 3726, (2000)]. Curie - Weiss fit to the cr' (T) data reveals negative value ofCurie- Weiss temperature as expected for an antiferroelectric transition. The
XRD measurements below phase transition temperature show new superlatticereflections. Rietveld analysis of XRD data reveals that structure of theantiferroelectric phase is doubled along c- axis of the paraelectric phase. The
space group of the antiferroelectric phase is shown to be Pbcm. The paraelectric
to antiferroelectric phase transition is marked by the appearance of new Ramanlines around 79cm-1 and 128cm- 1 with a concomitant enhancement in theintensity of the modes near 170 cm- 1 and 541 cm-1 on approaching theantiferroelectric phase transition temperature. Correlating the XRD and Raman
measurements, it is concluded that the new Raman lines are due to q;t 0 phonons
which become Raman active due to folding of the corresponding special points
into the zone centre (q=O) below the cell- doubling antiferroelectric phasetransition temperature [ S.K. Mishra et al Phys. Rev. B 64, (9), 092302 , (2001)].

Email: dpandey@banaras.ernet.in

A3-16
MODELING OF POTENTIAL IN TRIGLYCINE SULPHATE (TGS) USING SINGLECRYSTAL NEU'IRON S'IRUCTIJRE OF (TGS)

Rajul-Ranjan Choudhury, R.Chitra, M.Ramanadham,
Division, Bhabha Atomic Resea rch Center, Mumbai-85.

Solid

State

Physics

It is well known that out of three glycine molecules of Triglycine Sulphate (TGS)

labeled GI, Gil and Gill, it is GI located near the plane perpendicular to b axis at
0 .25b (mirror plane in paraelectric state) plays the most important role inpolarization reversal and ferroelectric phase transition. It is attempted to modelthe double well potential seen by GI using h ydrogen bond potential given by
Ramanadham et.al. (1978) and the potential for non-bonded interactions. The
Neutron structure ofTGS reported by Kay et.al.(l972) is taken as a starting pointin this attempt to model the potential seen by Glycine I as it flips between two of
its equivalent sites in the unit cell.
The results indicate a deep double 'well' kind of potential with the value of barrierheight much more than the value of thermal energy KT at room temperature. This
result is supported by the Ising kind· of behavior exhibited by TGS.
l. M.Ramanadham and R.Chidambram: Advances in Crystallography,
R.Srinivasan (Ed .) Oxford & IBH Publishing Co. (1978) p.81-103
2. M.I.Kay and R.Klienberg: Ferroelectrics 5, p . 45-52 (1972)

Email : rajul@magnum.barc .emet.in

A3-17
PHASE TRANSIDON IN K2Fe(S0 4 h .4H2 0

H. lshigamia, M. Shirob, T . Hikitac and S. Satod , aLaboratory of Natural Science,
Faculty of Engineering, Shibaura Institute of Technology, 307 Fukasaku,
Saitama, Saitama 330-8570, Japan, hX-ray Research Laboratory, Rigaku
Corporation , Akishima, Tokyo 196-8666, Japan , cDepartment of Applied Physics ,School of Engineering, Tohoku University, Aramaki Aoba, Sendai 981-8579,
Japan, and ctsato Laboratory. Kuboyamacho 1-9-109, Hachioji. Tokyo 192-0023 ,Japan.
In substances related to Mohr's salt, three compounds K2Fe(S0 4 b ·nH 20 (n=2 , 4
or 6) are known. The title compound showed anomalies of both specific heat anddielectric constant at 285k. Structure analyses were performed, therefore, at
303K [monoclinic, space group C2/m; a=ll.853(1). b=9.544(1). c=9.951(1)A;
P=94.81(1r; V=1121.7(5)A3; Z=4] and 123K (P2tfa, 2 =4). The cell dimensions
showed no drastic changes above and below the transition temperature. The
crystal consists of potassium cations and octahedral trans-[Fe(S0 4 b(H 20) 4 ]complex anions . Two complex anions with similar geometry exist in the cell ,which are chemically equivalent but crystallographically independent taking
different orientations. Each anion is highly symmetric in the high-temperaturephase: the Fe atom occupies a center of symmetry, the Fe-0-S-0 bonding lie inthe mirror plane, and there exists a two-fold rotation axis along the Fe-O(water)bond in one anion and that along the bisector of the O(water)-Fe-O(water) angle in
the other. The anions lose the mirror and two-fold symmetries in the lowtemperature phase, and slightly deform. This transition feature differs from thatof K2Fe(S0 4 h·2H 20 in which large rotational changes of the H 20 molecules wereobserved along with the halved cell volume in the high-temperature phase as was
already reported by the authors' group.

Email: ss310@f2.dion.ne .jp

A3-18TIIE EFFECT OF PRESSURE ON ARSENIC 1ELLURIDE (As 55 Te45
TRANSmON) PHASET K Mondal, N C Shivaprakash and K Rajanna., Department of Instrumentation,
Indian Institute of Science, Bangalore- 560 012 ., India
melt quenchingbyprepared
The semiconducting As 55 Te 45 glasses areis confirmedmaterial
quenched
theof
natureamorphousThemethod.
by X ray diffraction. High pressure differential thermal analysis system isused for this study. As 55 Te 45 is heated in the DTA cell at ambient pressure.
different
twoat
recorded
been
have
peaks
exothermicTwotemperatures 312.42 and 390.30 K respectively. These two peaks show the
double stage thermal crystallization. Later pressure is applied and the sample
exothermic peak is shifted to higher temperatureis heated . The first
320. 11 K and becomes sharp . One endothermic peak which does not appear atambient pressure, now exists at 0.13 GPa and at 323.96 K. The second
peak also shifts to higher temperature 405 .69 K. The sample As5 5 Te 45
glasses ' when heated s tarts restructuring towards longer range order and tries
to go to stable condition, by releasing some amount of heat. The firstaccounted for the same. This can be explained byexothermic peak is
Percolation theory. After translational movement of the atoms , the electronic
distribution starts. This is known as localization or delocalization of electrons
and is explained by Anderson transition. The appearance of endothermic
peak might be due to the fact that, there is one more orientation or the
restructuring of the phase at that temperature. The details are discussed in thispaper.
Ema il : tushar@isu .iisc .emet.in

~
X-RAY ANOMALOUS SCATIERING SnJDY OF TilE LOW-1EMPERATURE PHASEOF NaV2 0 5 BY USING ITS MONOCLINIC SINGLE DOMAIN

Y. Katsukia, J. Muraokaa, Y. Fujiia, N. Takesuea, M. lsobea. Y. Uedaa, K.

Ohwadab ,H. Nakaoc, E . Ninomiyad, H. Sawad and Y. Murakamie, alnstitute for
Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan, b
JAERI-SPring8 , Sayo, Hyogo 679-5148, Japan, cKEK-PF, Tsukuba, lbaraki 3050801, Japan, dFaculty of Science, Chiba University, Chiba, Chiba 263-8522 ,Japan and eGraduate School of Science, Tohoku University, Sendai 980-8578 ,Japan.
The quarter-filled spin-ladder compound NaV2 0 5 undergoes a novel phasetransition at Tc=35K associated with its spin, charge and lattice system. Its
orthorhombic phase (Pmmn) above Tc has a charge-disordered state as nominally
represented as V4 ·5+ , while below Tc charge-ordering as V4 + and vs+ [PRL 85(2000) 4349). formation of spin singlet ground state [JPCS 60 (1999) 1099] andatomic displacement modulated with q=(1/2, 1/2, 1/4) [JPSJ 66 (1997) 326] takeplace cooperatively. For last several years, however, no conclusive structure forthe low-temperature phase has been obtained. Very recently Ninomiya et al.
[private commun .] succeeded in a very precise structure analysis, claiming a
monoclinic phase (All2) and observed a concomitant monoclinic splitting offundamental reflections by synchrotron x-rays.
In the present study, we have carried out an anomalous scattering experimentacross the K-edge of V ions (V4 + and V5+j to fully determine a charge-ordering
pattern by using a single domain at Photon Factory. A significant difference insuperlattice intensity spectrum as a function of x-ray energy is observed between
two kinds of monoclinic domains to offer a key information on the charge orderingand a full structure analysis is under way to complement Ninomiya's structure
analysis.
Email: katsuki@issp.u-tokyo. a c.jp

A3-20ON
STIJDIES
TEM
LOW-TEMPERATIJREFERROMAGNETIC DOMAINS IN MANGANITESCHARGE-ORDERINGAND

T. Nagaia· b , T. Asakaa, b , S . Moric, K. Kimotoa & Y. Matsuia· b, a National Institutefor Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan. b Dept. of Res. &Environmental Engineering, Waseda Univ., Tokyo 169-8085, Japanc Dept. of Materials Science, Osaka Pref. Univ. , Sakai 599-8531, Japan
Low-temperature analytical and Lorentz TEMs are applied to the phenomena of
Most ofcharge-orbital ordering and ferromagnetic domains in manganites.
experiments were made by two 300kV Cold-FEG TEMs (Hitachi: HF-3000): (a)analytical TEM with EDX and EELS-based imaging system (GIF), and (b) Lorentztype TEM in which specimen is isolated from the magnetic field of the objective
lens. Both liq.He and liq.N 2 cooling holders (Oxford Inst.) were used to cool the
specimen below Teo (charge-order temperature) or Tc (Curie temperature).
Charge-orbital ordered structures of layered manganites, Nd 1 _xSr 1+xMn0 4 (x=2/3& 3/4}, were studied by analytical TEM, and sinusoidal structural distortion
giving rise to the superstructure was successfully observed in HRfEM images
The observation suggests that the "Wigner-crystal" modeltaken below 150K.
Directbest explains the charge-orbital ordered structures in manganites.
observation of ferromagnetic domains were made, by low-temperature Lorentz
electron microscopy, for Ndo.5Cao.5Mn 1_xCrx03 (x=0-0. 1), and it was confirmed for
x=0 .02 compound that small ferromagnetic domains coexist with charge-orderedmatrix. Volume fractions of ferromagnetic domains dramatically increase with x,
although charge-ordered domain survives even for x=0.1.
Email : MATSUI.Yoshio@nims .go.jp

A3-21

ORBITAL ORDERING OF TRANSIDON-METAL-OXIDES OBSERVED BYRESONANT X-RAY SCATI'ERING

Youichi Murakami. Department of Physics, Tohoku University, Sendai 980-8578,
Japan·
Orbital degree of freedom plays important roles in electric and magnetic properties
in a strongly correlated electron system. The method of measurement for orbital
ordering, however, has been limited so far. Recently it has been pointed out thatsynchrotron x-ray diffraction is a very powerful tool to observe the ordering. In
particular the resonant x-ray scattering (RXS) technique has been developed todetect the orbital ordering for last few years[ 1]. This is a technique combining
diffraction wjth spectroscopy. By using this technique the orbital states invarious systems have been elucidated[2], though the microscopic mechanism of
the resonant x-ray scattering ' is still controversial.. Here, we will report new
results of perovskite transition-metal-oxides observed by RXS.
[1] Y. Murakami et al.: Phys. Rev. Lett. 80 (1998) 1932; ibid. 81 (1998) 582.
[2] Y. Endoh et al.: Phys. Rev. Lett. 82 (1999) 4328; K. Nakamura, et al.:Phys.
Rev. B 60 (1999) 2425; M. v. Zimmermann, et al.: Phys . Rev. Lett. 83 (1999)
4872;
K. Hirota et al.: Phys. Rev. Lett. 84 (2000) 2706; Y. Wakabayashi et al.: J. Phys .
Soc. Jpn. 69 (2000) 2731; M. Noguchi, et al.: Phys. Rev. B62 (2000) 17.
Email: murakami@min.s.u-tokyo.ac.jp

A4 : Crysta llogra phy in chem istryA4-lCRYSTAL S1RUCTURE ANALYSIS OF 1WO CHROMANONES

A.Jeyabharathil,M.N.Ponnuswamy 1 • S. Manikar1dar1 2 ar1d R .Ragunathar1 2 · 1.
Department of Crystallography and Biophysics, University of Madras GuindyCampus,Chennai-25 2. Department of Chemistry, University of Madras, GuindyCampus Chennai-25.
Two chromanones with different substitutions are taken for crystallographic study
and the results are presented. The compound I crystallizes in monoclinic spacegroup P2Ifa with cell dimensions a= 16.412(4). b = 8.715(5). c = 16.524(2) A. ~ =118.61(1) 0 , V= 2072(8) A3 ar1d Z= 4. The compound II crystallizes in monoclinic
space group P2Ifc with a= 10.366(1). b = 14.145(1) c = 15.334(1) A.~= 99 . 14(2) 0 ,V =2222. 7(4JA3 and Z= 4. Both the structures were solved by direct methods arid
refined to final R-value of 0.0638.
C-H ... 0 type of intermolecular interactions
help to stabilize the molecules in the unit cell in addition to van der Waals forces.
It is interesting to note the presence of C-H .. .n interactions in both thecompounds.
Chromar1ones are less toxic when compared to flavanoids . There exists a marked
difference between the toxicity of the chromar1ones arid the simple flavar1oids arid
this was attributed to the absence of the side phenyl ring in the chromar1ones.
The chromar1ones were claimed to be active against trichomonas, Gram- positive
and Gram- negative bacteria and fungi. Mar1y 4-chromarione derivatives are usedas starting materials for the synthesis of natural products such as hematoxylin,
brazillin --etc.
Email : jeyari46@yahoo .com

A4-2

S1RUCTIJRAL ANALYSIS OF 'IWO .DIFFERENT PIPERIDONES

A.Nallinia, M.N.Ponnuswamya. K.Venkatrajb and R.Jeyaramanb a Department of
Crystallography and Biophysics , University of Madras, Guindy Campus, Chennai
India. b Department of chemistry, Bharathidasan University.
- 600025,
Tiruchirapa1li - 620024.
The transition of piperidones active form, from 'chemical' to 'pharmacological' be
detected through the identification of structural relations between their different
forms. To establish the structures, the following two piperidones are studied bycystallographic methods .
crystallizes
1. CADMP0(2. 6-diphenyl-N-choloroacetyl-3. 5-dimethyl-4-piperidone)in monoclinic space group P2 1 with cell parameters a = 8 .2082(1). b = 10.4899(1).
c = l0.6175(l)A. (3 = 91.833(1) 0 , V = 913.73(2)A3. Z = 2 and refined to a fmal Rvalue of 0 .0399.
2. CAEP0(2,6-diphenyl-3-ethyl-4-piperidone) · crystallizes in monoclinic spacegroup P2Ifn with cell parameters a= 10.3626(6). b = 8.5702(5). c = 21.6930(1)A.
(3 = 92.250(1) 0 , V = 1925.06(2)A3, Z = 4 and refined to a final R-value of 0.0623.
The displacement of alkyl groups in going from CADMPO to CAEPO sets forth
only a very few uncommon features in their geometry. The two piperidones exhibitakin structural features like involvement of C-H .. .O type interactions in theirpacking and adoption of twist-boat conformation by their heterocyclic rings.
imputing structural stability.
Email: brvrangan@hotmail.com

A4-3

X-RAY CRYSTAL S1RUCnJRES OF 1HREE ISOQUINOLINE DERIVATIVES

A. Subbiah Pandia.c, V. Rajakannanc, P.R. Seshadrib.c, D. Velmurugaric. Senthil
Velavand and S. Narasinga Raod · anepartment of Physics, Presidency College,
Chennai- 600 005., bDepartment of Physics, A.M. Jain College, Chennai- 600 114.
And cnepartment of Crystallography and Biophysics, University of Madras,
Guindy Campus, Chennai-600 025. dDepartment of Organic Chemistry,
University of Madras, Guindy Campus, Chennai-600 025. University of Central
Oklahoma, USA.
Isoquinoline is a ligand , which is used as a complexing agent for different metals .
Tetrahydroisoquinolines
represent
a
class
of
biologically
activephenylethylamines. The 4-substituted tetrahydroisoquinolines have potent
pharmacological activity. The title compounds [C 16H 12ClN0 2 (I). C 15H 12 BrN02 (II)and C 1sH 9 Cl2N0 2 (III)] crystallize in monoclinic space groups P2tfn for I and II
and P2tfc for III . The asymmetric unit contains three molecules for one moleculeand I for II and III respectively. The structures were solved by Direct Methods
using SHELXS97 and refined using SHELXL97 to the R-values 6.5%, 4 .2% and
3 .5 % respectively. The molecular packing is stabilized by weak C-H ... O hydrogenbonds. Conformational parameters are calculated and compared. The structuraland conformational analysis of these three compounds will be discussed during
presentation.
Email: asp@md4.vsnl.net.in

A4-4
STIJDY OF WEAK INTERACTIONS IN (4-CHLOROPHENYL) (4-FLUOROPHENYL)PYRIDINE - 4- YL- METHANOL AND BIS (4-FLUOROPHENYL) PYRIDINE - 4- YL-METHANOL

A. R. Choudhurya, U. K. Ursa, P. S. Smithb, R. Goddardc, J. A. K. Howardb· and T.
N. Guru Rowa, asolid State and Structural Chemistry Unit, Indian Institute of
Science, Bangalore 560012, India, bDepartment of Chemistry. University ofDurham, Durham DH1 3LE, U.K. cMax planck institut fur kohlenforschung,
Kaiser-Wilhelm- Platz 1, D-45470 Mulheim an der Ruhr, Germany.
In continuation of our investigations on weak interactions involving fluorine, we
present the crystal structure of two compounds. Both the compounds form chainswith the molecules linked by 0-H ... N hydrogen bonds as observed in diphenyl (4pyridyl) methanotl In addition C-F ... n interactions 2 are observed as aconsequence of the fluorine atom being flanked by the phenyl rings of theneighboring molecules. In the first structure, we also observe a significantly shortintermolecular Cl...Cl interaction3 [type I, Cl...Cl = 3.4213(9) A. LC-Cl...Cl' =127.2°) but no other halogen ... halogen interactions are present. However, thesecond structure does not have any F ... F interaction. A comparative study ofthese structures in the context of weak interactions will be discussed.
l. C. Glidewell and G. Ferguson, Acta Cryst. (1994) C50, 924.
2. M.D. Prasanna and T. N. Guru Row, Cryst. Engg. (2000) 3 , 135.
3. G. R. Desiraju and R. Parthasarathy, J. Am. Chem. Soc., (1989) 111 , 8725.

Email : ansu@sscu.iisc.emet.in

A4-5
X-RAY
CRYSTAL
S1RUCIDRE
BIS('IRIPHENYLPHOSPIDNE)NICKEL

OF

1WINNEDBROMONI'IROSYL-

Angkana Kiatphichitpong, and Kenneth J . Haller, School of Chemistry, Institute of
Science, Suranaree University of Technology, 111 University Avenue, Nakhon
Ratchasirna 30000 Thailand.
The title complex was synthesized from the corresponding dibromo complex byreaction with nitrite anion as the source of the nitrosyl ligand. The diffractometer
determined unit cell is triclinic containing four molecules of the complex. It wasnoted that the mosaicity parameter and cell parameters changed as the data
reduction proceeded. Solution of the two molecule asymmetric unit wasstraightforward, but the two molecules appear to be nearly identical. Examination of
the intensity data show the systematic condition Okl, k = odd absent, andexamination of the cell packing suggests the presence of a glide operation and ascrew operation in addition to the inversion center required by the P- 1 space group,
leading to the conclusion that the true space group is P2 1 I c. Synthetic precession
photographs obtained from the frame data clearly show the twinning of the parent
lattice giving rise to the apparent triclinic cell.
Crystal data: c36H3oNiNOP2Br; Mr = 693. 17 Daltons; dark purple; 0.09 X 0.16 X 0 .30
mm; hexagonal plate; triclinic; P-1 (No. 2), a = 9.6411(1). b = 14.8944(2). c =22.7806(4) A. a= 79.5670(5) /3 = 85.9471(5) r= 90.0044(9) 0 , v = 3208.85(8) A3 z = 4,
fJ, = 1.98 mm- 1 ; deaLe= 1.435 Mg/m3., A.MoKa = 0.71073 A; T = 200 K. Data collection:
Nonius KappaCCD; 0.5 mm ifg capillary collimator; Oxford Cryosystems LT device;
53796 data collected (triclinic) ; 18564 unique; 12720 observed.

Email: angkajane@yahoo.com, haller@ccs.sut.ac.th

A4-6
SYNTIIESIS AND CRYSTAL STRUCTURES OF 6-(4-CHLOROPHENYL)-3-CYAN04-[N'-BIS(4-FLUOROPHENYLMETIIYL)PIPERAZIN0]2H-PYRAN-2-0NE AND ~(4CHLOROPHENYL)-2-CYCWPROPYL-6-[N'-(2-PYRIDYL)PIPERAZIN-1YL]BENZONITRILE.

Ashoke Sharon, Vishnu J. Ram, Pratibha Srivastava, Nidhi Agarwal and Prakas R.
Maulik. Molecular & Structural Biology Division andMedicinal Chemistry
Division, Central Drug Research Institute, P. B. No . 173, Lucknow 226001, India.
6-(4-Chlorophenyl)-3-cyano-4-[N'-bis(4-fluorophenylmethyl) piperazino)2H- pyran2-one(1)and
4- (4-chlorophenyl)-2-cyclopropyl-6-[N'- (2-pyridyl)piperazin -1yl)benzonitrile (2). Compounds 1 and 2 were synthesized by nucleophilic
substitution by sec-amine on suitably functionalized 2H-pyran-2-one followed byring transformation from cyclopropyl methyl ketone in presence of base.
Diffraction quality crystals were obtained by slow evaporation of solvent at room
temperature.
·
Structures of 1 and 2 were solved by direct methods and refined anisotropicallyby full-matrix-least-squares method on F 0 2 . The molecular structure of 1 showedthat the piperazine ring (B) adopts a chair conformation and the N7 and N 10
substituents are in equatorial positions. There is an intramolecular H-bonding.
The crystal packing revealed a network of various weak intermolecular H-bonding(C-H ... O, C-H ... N and C-H ...F) and aromatic n-n interactions (APPI) . Currently theimportance of these interactions is being realized in crystal engineering andsupramolecular design. Both the chlorobenzene (E) and lactone (A) rings arestacked in pair due to APPI. The molecbl.les are stacked in such a way that ring A
overlap with ring B and vice-versa. In addition, one of the fluobenzene rings, ringD, also shows APPI. Thus the combination of weak H-bonding and aromatic n-ninteractions mainly stabilize the molecules in crystalline state. The crystal
structure of 2 showed that the asymmetric unit contains two molecules of similar
conformations . The piperazine ring (C) adopts a chair conformation. The crystal
packing revealed the presence of weak intra- and intermolecular C-H ... N and CH .. .n interactions that play a fundamental role in three-dimensional organizationof the molecules in solid state. The above pair of compounds 1 and 2 arehighlighting the noncovalent weak intra-and intermolecular interactions.
Knowledge of noncovalent interactions between molecules will help inunderstanding the molecular recognition process.
Email : ashoke_sharon@hotmail.com

A4-7
C-HAWGEN···n SYNTIION IN POlAR CRYSTAL PACKING

Ashwini Nangia, School of Chemistry. University of Hyderabad, Hyderabad 500
046
It has been shown by us that 4-halophenox:ytriazines 1 self-assemble via thetriangulo halogen synthon to produce hexagonal cavities and channels that
includevarious
guest
speciessuch
asbenzene ,trinitrobenzene,
hexachlorobenzene, hexamethylbenzene , hexamethylphosphoramide (1,2). These
isomorphous host-guest clathrates crystallise in P6 3 /m space group with a= b =15.5 A. c
6.9 A. A notable feature of these crystal structures is that they arestabilised by the weak interactions, halogen···halogen, C-H···O, C-H·· ·N, CH·· ·halogen.

=Co-crystallisation of triazine 1 with tribromobenzene (tbb) and triiodobenzene (tib)guests afforded inclusion crystals in P6 3 space group with similar cell axes
compared to the centrosymmetric family. Thus, internal reorganisation of tbb andtib guest species and host phenoxy rings in the hexagonal nanotubes does not
perturb the lattice parameters compared to the P6 3 /m structures. A plausible
reason for chiral crystallisation with trihalobenzene guests is the polar chain ofalternating C-halogen(guest)···n(host) and C-H(guest) ···n(host) interactions andthe herringbone packing between screw axis related host phenoxy rings . The
recurrence of P6 3 space group in four host-guest crystals suggests that the weakC-halogen···n synthon induce enantiomorphous crystallisation (3) . The selfassembly of chiral crystals from achiral or racemic components is of importancein crystal engineering, materials applications and in the understanding of
spontaneous resolution during crystallisation.

0«x'On \~
1: X= CI. Br

~ I

¢
'-"'

y

y

ox

~

v

y .. er. lXxl""'il

NXN

VJlA
o
N~~
1: X=CI. Br

y

v~v

Y

v
Y=Br. lX

R.K.R. Jetti, F. Xue, T.C .W. MakandA. Nangia, Cryst. Eng., 1999, 2, 215.
2. R.K.R. Jetti, P.K. Thallapally, F. Xue, T.C.W. MakandA. Nangia. Tetrahedron ,2000 , 56, 6707.
3. R.K.R. Jetti, A. Nangia, F. Xue and T.C.W. Mak, Chem. Commun., 2001, 919.
l.

Email: ansc@uohyd.ernet.in

A4-8
X-RAY CRYSTAL S1RUCWRE OF 1HE SUPRAMOLECUIAR CALCRJM VANADRJMOXIDE,CaV2 0 6

Aungkana Chatkon and Kenneth J. Haller, School of Chemistry, Institute of
Science, Suranaree University of Technology, 111 University Avenue, Nakhon
Ratchasima 30000 Thailand.
The title compound was prepared from calcium chloride and ammonium vanadateby hydrothermal synthesis. Examination of synthesized undistorted spaceprecession photographs revealed weak non-Bragg intensities along the b* axial
direction which can be indexed to the parent cell with a fourth index q such that q =k + nq: Only the q = ±1 intensities can be seen in In the hkn zones, while the q = ±1
and ±2 intensities can be seen in the nkl zones.
The parent structure easily refines to R 1 = 0.0401 for the 347 unique independent
parent data collected. Orientations of individual anisotropic atomic displacement
parameters suggest positional movements to account for the observed structure
modulation.
Crystal data: CaV2 0 6 ; Mr = 222.85 Daltons; light green transparent 0.075 x 0.20 x0.60 mm needle crystal; monoclinic parent cell; C2/m (No . 12), a= 10.086(1), b =3.672(1), C = 6.995(1) A, {3 = 105.19(1) 0 , V = 250.02 A3 Z = 2, AMoKa = 0.71073 A; T =200 K (Nonius KappaCCD I Oxford Cryosystems).
Email : tuy448@yahoo .com,haller@ccs.sut.ac.th

A4-9

X-RAY S'IRUCTIJRE CHARAC1ERIZATION OF DISORDERED FRIEDELIN-3-0NE
AND EPIFRIEDELIN-3-0L

Auphatham Phothikanit and Kenneth J. Haller, School of Chemistry, Institute of
Science, Suranaree University of Technology, 111 University Avenue, Nakhon
Ratchasima 30000 Thailand.
Preliminary results of a structure correlation study of the friedelanes that have b een
previously characterized (taken from the Cambridge Crystal Structure Databa se) bysingle crystal x-ray studies revealed an anomaly in the sum of the C-C-C and two 0C-C angles about the oxygen substituted C3 position in ring A. The distance, 1.33 A,
and the sum of angles, 343. 1 o , in epifriedelin-3-ol are intermediate between theideal values (1.21 A and 360.0 °) for sp2 hybridization and (1.43 A and 328.5 °) forsp3 hybridization.
An explanation for the anomalous case can be suggested from an independent
structure determination based on a crystal obtained from the rhizome of DavaHia
salida Sw, and having the same cell constants and space group as the anomalous
compound; colorless clear plate crystal, 0.12 x 0.40 x 0.42 mm, of mixed friedelin-3one, CsoHsoO. I epifriedeliln-3-ol, Cs 0 H 52 0. Monoclinic C2 (No. 5}, a= 13.437(3},b = 6 .430(1}, c = 29.599(6) A, {3 = 91.97(3} 0 , 295 K, Z = 4 , deale= 1.109 Mg/m3. Data
collected on a Bruker /Siemens SMARr equipped with MoKcx x-radiation. The single
crystal structure exhibits two well-separated peaks for the oxygen atom position.
The two peaks were modeled as partial oxygen atoms with occupancies onstrained
to a sum of one. One peak corresponds to a ketone at position C3 and the other toa hydroxyl group at position C3. The average of the C-0 distances and the averageof the sum of the angles about C 3 for the disordered structures corresponds to theanomalous values

Email: g4011149@ccs.sut.ac.th, haller@ccs.sut.ac.th

A4-10RARE EARTH COMPLEXES OF P-T-BU1YLTE1RATHIACALIX[4].ARENE

Alexander Bilyka•John Dunlopa•Annegret K. Halla•Jack M. Harrowfielda· Brian W.
Skeltonb and Allan H. Whiteb,aspecial Research Centre for Advanced Mineral andMaterials Processing, b Department of Chemistry and Crystallography Centre,
University of Western Australia, Crawley, WA 6009, Australia.
The calixarene. p-t-butyltetrathiacalix[4]arene (LH4) has exhibited a propensity forthe stabilisation of transition metal clusters and the term cluster keeper has beencoined to describe this calixarene. The clusters are stabilised because in the cone
conformation of L the S and 0 donor atoms act as a surface which canaccommodate more than one cation. The key to the coordinating properties of L isdue to the bonding of · the S atoms with the metal ions. which is not the case formethylenes in conventional calixarenes. To continue on with our investigations
into the coordination chemistry of L, we switched our focus to the rare earths
where it was found that these cations also form clusters on mixing with L. Twotypes of clusters were isolated, a neutral 3Eu + 2L ( l) and a charged 4Nd or 4Pr +2L (2. 3) cluster. In both types the rare earth ions are sandwiched between thetwo calixarenes. Each cation is bonded to sulfur and also to two small ligands,
either dmf. the reactant solvent, or dmso. which is present in starting materials .
Email: bws@crystal.uwa.edu.au

A4-11X-RAY CRYSTAL STRUCTIJRE OF AN ANTIDEPRESSANT CLASS OF DRUGS:DESIPRAMINE-HYDROCHLORIDE

Noor shahina Begum·. C.R.Girija and Syed Akheel Ahmed a. . Department ofstudies in chemistry, Bangalore University, Central College Campus, Bangalore
560 001 , India. a Department of studies in Chemistry , Mysore University ,Manasa
Gangothri, Mysore-570 006, India .
The title compound is a tricyclic antidepressant of dibenzazepine class of drugs .
The dibenzazepine class of compounds encompass a broad spectrum oftheoretical and applied disciplines. At the theoretical level,chemists are fascinatedby these compounds from the molecular standpoint. At the applied end of thespectrum ,an enormous amount of research on depressive disorder has been
conducted in pharmaceutical laboratories and the efficacy of dibenzazepine inelevating depression has been well established.
In view of the above medicinal importance , the X-ray crystal structure analysisof the title compound has been carried out. The compound crystallizes in triclinic
spacegroup P1 with cell parameters a = 10.8504 (5).A. b =16.2316(7)A.
c=20.6943A. =72.057(2)0, (3 = 89.980 (2)0, y =80.465(2)0 z = l. The structure
was solved by direct methods using SHELXS-97 and refined by full-matrix leastsquares method using SHELXL-97 to a fmal R-factor of 0.10. The details of thecrystal structure will be discussed .
Email : girij ashivakumar@rediffmail. com

A4-12CRYSTAL AND MOLECULAR STRUC'IURE OF
NORBORNENE-END0-5, 6-DICARBOXYUC ACID

SYN-7-TRIMETIIYLSILYL-2-

Noor Shahina Begum •. C.R.Girija and Gopalpur Nagendrappa. Department ofstudies in Chemistry, Bangalore University, Central College Campus, Bangalore·
560 00 1, India.
The structural elucidation of the title compound was undertaken as the regia andsteriochemistry of the compound is essential to understand the steriochemical
behaviour of trimethylsilyl-cyclopentadiene in Diels-Alder reaction. X-ray crystal
structure analysis of the title compound has been determined. The compound
crystallizes in monoclinic spacegroup P2 1 .with cell parameters a =8.1506(2lA. b =7.6964(l)A, c =22 .5962(5)A, (3 =90 .33· , Z=2 and V= 1417.44 A3 . The structure
was solved by direct method using SHELXS-97 and refined by full-matrix least squares method using SHELXL-97 program.The final R- value is 0 .0478 for
2186 unique reflections. It is confirmed from the crystal structure that thetrimethylsilylgroup is on the same side as the double bond and the two carboxylic
This indicates that in the transition state the bulkygroups are endo.
trimethylsilyl group takes least hindered position. The details of the crystal
structure will be discussed.
Email : girijashivakumar@rediff.com

A4-13

CRYSTAL AND MOLECUlAR S'IRUCTURE OFCYCWPENTANE-1, 2,DIOL

CIS-1-(TRIMETHYLSILYL)-

Noor Shahina Begum·. C.R.Girija, Gopalpur Nagendrappa and M.NarendraMallya
Department of studies in Chemistry, Bangalore University, Central College
Campus, Bangalore 56000 1, India.
1,2,Dihydroxysilanes are versatile synthetic intermediates. The chemistry of cyclic
cis-1,2-silyldiols is little explored. Their crystal structure study is of particularinterest due to the possible Si. ... O interaction and the usual intra and intermolecular hydrogen bonding in diols.The title compound is one of the series ofcyclic silyldiols which are being studied for understanding the conformational
effects on hydrogen bonding.
The title compound crystallizes in the monoclinic space group C2/c with
a=21.5441(15)A b=9.0715(6)A c=10.99956(7)A f3 =100.83 (0) 0 and z =4.The title
compond was solved by direct methods using SHELXS-97 and refined by fullmatrix least- squares on F2 using SHELXL-97 to an R-value of 0.0679 for 1042
reflections with I>2cr (I) collected using a Siemens Smart- CCD diffractometer with
MoKa radiation.The structural and conformational analysis will be discussed indetail.
Email: girijashivakumar@rediff.com

A4-14

CRYSTAL AND MOLECULAR STRUCTURE
MORPHOLINE)P- CRESOL

OF

2 ,6,-BIS-(THIOCARBONYL

Noor Shahina Begum •. C.R.Girija and T.Narasimhamurthya. Department ofstudies in Chemistry, Bangalore University, Central College Campu s, Bangalore
560001, India . a Bioinformatics liSe Bangalore-56000 12, .India
X-ray crystal structure analysis of the title compound has been determined. The
compound crystallizes in monoclinic spacegroup P2 1; a with cell parameters a=9 . 191 (2) A b =21.932(6JA. c =9.609(2)A. {3 =111.6(2)0, z ·=4 and V=1800.1(8)A3 .
The structure was solved by direct methods using SHELXS-97 and refined by full matrix least- squares method using SHELXL-97 program. The final R- value is
0 .069 with 1>2cr(I) collected using Enraf-Nonius CAD-4 diffractometer with CuKcx.
radiation. The details of the crystal structu re will be d iscussed .
Email: girijashivakumar@red iff.com

A4-15
CRYSTAL AND MOLECULAR STRUCTURE OF A BRIDGED CHLOROCYCWMETALIATED COMPLEX OF CU(ll) WI1H ETHANOLAMINE AND pCRESOL

Noor Shahina Begum •. C.R.Girija and T.Narasimhamurthya Department ofstudies in Chemistry. Bangalore University, Central College Campus, Bangalore
560001 , India.
a Bioinformatics Centre , liSe Bangalore 560012 . India.
X-ray crystal structure analysis of the title compound has been determined. The
compound crystallizes in monoclinic spacegroup P2Ifc with cell parameters a=ll.919(10)A b =18.726(10)A, c =15.586(10)A, (3 =103.880(10) 0 , z = Sand
V=3377.14A3 . The structure was solved by direct methods using SHELXS-97 andrefmed by full-matrix least- squares method using SHELXL-97 program. The
final R- value is 0.1589 for unique 2720 reflections with I>2cr(I) collected using
Enraf-Nonius CAD-4 diffractometer with CuKcx. radiation. Further refinement isunder progress. The details of the crystal structure will be discussed.
Email: girijashivakumar@rediff.com

A4-16SYNTifESIS, CHARAC1ERIZATION AND PROPERTIES OF 1ERTIARY COPPER(U)COMPLEXES OF REDUCED SCHIFF BASE N-(2-HYDROXYBEN:lYL) a-AMINO
ACIDS AND 1,10-PHENANTIIROLINE

Chang-Tong Yang, and Jagadese J. Vittal.Chemistry Department, National
University of Singapore. 3 Science Drive 3, Singapore 117543.
Copper(II) temary complexes with reduced Schiff base ligands (N-(2hydro:xybenzyl)- a-amino acids) (H 2L) and 1, 10-phenanthroline have beensynthesized and characterized. By changing the metal-ligand ratio, counterions
and pH of the solution , three types of compounds were synthesized andcharacterized in the solid state as well as in solution. They are neutral monomers,[Cu(L)(phen)] •xH 20 (L = sgly, sala, sval); monodeprotonated complexes ,[Cu(HL)(phen)](Cl0 4) •xH 20 and dimeric complexes. [Cu 2(L)(phenb)(Cl0 4h •xH20.
The molecular structures of the representative compounds are shown below.

~~0

~'"'u
OH

OH

R=H,

H:1sgly%.

~aQ-i( OiJl2, H:1sval

<~~:

~~

~

Neutral monomer[Cu(sgly)(phen)]

Helical polymer[Cu(Hsala)(phen)](Cl0 4)

Deprotonated monomer[Cu(Hsgly)(phen)](Cl0 4)

Dimer[Cu2(sgly)(phenb](Cl04h

The intra- and intermolecular weak interactions present in the solid state will be
discussed in detail.
Email : chmjjv@nus .edu .sg

A4-17
HYDROGEN BONDING IN1ERACTIONS IN 1ERNARY Cu(ll) COMPLEXES[Cu(X)(Y)] WHERE X=SQUARA1E, Y=2,2'-BIPYRIDYL/1,10-PHENANTHROLINE:
SYNTHESIS AND SINGLE CRYSTAL INVESTIGATIONS.

Suresh.E. Silicates and Catalysis Division , Central Salt and marine Chemicals
Research Institute. G.B.Marg, Bahvnagar-364 002, India.
Two novel ternary Cu(II) networks [Cu(Sq)(2,2,bpy) (H 20)lnl [Cu(Sq) (1,10-phen)(H20)] .2H 20 2 with squarate and N-donor lignds 2-2'bpyridyl and 1,10
phenanthroline has been synthesized and characterized by various phyicochemical methods such as C. H. N, IR and single
crystal X-ray diffraction technicque. The structuralinvestigation revealed that [Cu(Sq)(2,2,bpy) (H20)ln
1 is a linear coordination polymer
with theadjacent metal centers are bridged via squarate
dianion. The 0-H .... O H-bonding interaction of thesquarate and the water between the adjacentlayers impart more dimensionality forming sheet
like structural pattern .
Complex 2 can be described as a H-bonded two dimensional sheet. The discrete
molecules are associated in pairs with the axial water molecules pointing in
opposite direction and packed along b-axis witheffective stacking interaction of the phenyl rings
fromadjacent
pairs.
Strong interandintramolecular 0-H ... O interactions between theneighoubring layers along a-axis forms a twodimensional H-bonded network as shown in fig.2.
The of the structural patterns in 1 and 2 may be
may be governed by the stacking of the N-donor
ligand and 0-H ... O H-bonding interactions . The
various intermolecular interactions
involved in the construction of
supramolecular arcitecture will be dicussed in detail.
Email: sureshel23@yahoo.com

A4-18

CONTROLLING
TlllOIATES

AUROPHllJC

INTERACTIONSPHOSPHINEGOLD(I)IN

Edward R.T. Tiekink Department of Chemistry, National University of Singapore ,SINGAPORE 117543.
The energy of stabilization associated with hydrogen bonding and aurophilic(Au ... Au) interactions in the solid state is about the same. This observation has
sparked considerable interest into the examination of the complementarity, or
indeed competition, between these modes of association.
Our work on
phosphinegold(I) thiolates, i.e. compounds with the general formula R 3 PAuSR' ,has shown that it is possible to 'encourage' aurophilic interactions at the expenseof hydrogen bonding interactions and vice versa.
For example, ribbons ofmolecules
are
found
in
the
crystalstructureof{[2C(=O)NH2lCsH4SAuPh2PC5H4FeC5H4PPh2AuSCsH4[C(=O)NH2-2]},I,
whichfeatures hydrogen-bonding interactions but no aurophilic interactions.

?
:

,o

,

s- Au- P~
Ph 2~

p-Au-<]0
/H
,H- N

Ph 2

~''

,

,'

II

'/

\\

'\

N-H

I

~

I

.

•

Substituting one hydrogen atom of the amide with a methyl group disrupts thisstructure in so far as intermolecular hydrogen bonding of the type seen in I no
longer exists; the intramolecular hydrogen bonding between theN-HandS atoms
persists. The removal of the dual hydrogen-bonding functionality now allows forthe formation of aurophilic interactions.
The results of recent structural studies, including structures obtained with theaid of synchrotron radiation, as well as ramifications for the luminescencecharacteristics of these materials will be described.
Email : chmtert@nus.edu.sg

A4--1 9SYNTIIESISANDSTRUCTIJRE

OF

TIIE

INCLUSIONCOMPLEXOFCYCWMALTOHEPTAOSE(~-CYCWDEXTRIN)WITI:I M-AMINOPHENOL

Fang-Ming Miaol, Shi-Kun Ma 2, Wei-Hong Zhou 1 ·3 and Jin-Ling Wang' 1 College ofChemical and Life, Tianjin Normal University, Tianjin, 300074, P.R.China.
2Institute of Public Health, Tianjin Medical University, Tianjin 300073, P . R
China. 3Biological Department, Tsinghua University, Beijin, 100871 , P. R China.
Supramolecular compounds are systems with special functions, depending on the
weak molecular interactions (such as Vander Waals, hydrogen bond, electrostaticand hydrophobic interactions). The supramolecular compound, ~-CD-m­aminophenol ((C 4 2H 7 o035) (C5H 7 0 1 Nd (H20h.5 CH30H] was synthesized anddetermined by X-ray diffraction analysis. Monoclinic, P2 1 space group , with a =1.5122(4), b = 1.0335(4), c = 2 .0915(3) nm, ~ = 109.58(2) 0 , V= 3.0798(3) nm 3 andfinal R=0 .0598 . The perspective drawing of the title compound is shown in Fig 1.
The system belongs to the "shallow inclusion" type which is rarely found, in which
the guest is located over the narrow rim of the host. There are so many hydrogenbonds that they build a dense hydrogen bond net. The hydrogen-bond interactionis the main force to form the whole system and keep it stable.

Fig 1. The perspective Drawing of the title Compound
Email: miaofm@public.tpt.1j.cn

A4-20PHASE TRANSmONS OF ORGANIC CRYSTALS CAUSED BY CONFORMATIONALCHANGES OF ALKYL CHAINS

F. Iwasaki, H. Matsumoto, N. Miki, D. Hashizume and M. Yasui, Department ofApplied Physics and Chemistry, The Univ. of Electro-Communications, Chofu,
Tokyo 182-8585 , Japan.
Organic crystals often show phase transitions coupled with order-disordertransformations of molecular moieties. However, very few studies have been doneon the detailed structural changes during transitions,· because of the crystal
damage and difficulties of intensity measurements for single crystal structure
analyses at various temperatures. Recently, temperature-dependent structure
analyses became possible through the development of diffractometers with twodimensional detectors . Crystals of acridin-N-oxyl derivatives with a long alkyl
chain (CnH2n+l• n =12, 13) showed that the first order transition occurred at 170
and 259K for n =12 and n=13 derivatives, respectively. In the case of the n =13,
the single crystalline states were kept during the transition Structure analyses
were carried out during the transition from 264 to 252 K every 2 K and at 295,
280, 273, 244 and 100 K. Crystals of N-4-methylpentanoyl-N-ethylurea showed aphase transition at 367K (mp=378 K) and also kept single-crystalline-state during
the transition. Structure analyses were performed at 98 , 298, 328 K and in therange of 348 - 374 K every 2 K. In these crystals a long alkyl chain became
disordered at high temperature phase. The detailed mechanism of the phasetransition, conformational change of alkyl group induced by the thermal
expansion, will be reported.
Email: fuji@pc .uec .ac.jp

A4-21X-RAY

CRYSTAL

S1RUCTURE

ANALYSIS

OF

17-0X0-16-(2-PYRIDYLMETIIYLENE)ANDROST-5-EN-3~-0L MONOHYDRA'IE

G. VASUKI V. PARfHASARATHI K. RAMAMURfHI . Department of Physics,
Bharathidasan University, Thiruchirappalli- 620 024 .
Epiandrostene derivatives are known to possess various medicinal and biologicalactivities. The crystal structure analysis of the title compound 17-oxo-16-(2pyridylmethylene)androst-5-en-3~-ol monohydrate, C 2 5 H 3 1 N 0 2 .H2 0 , has been
determined by the x-ray diffraction method. The compound crystallizes inmonoclinic space group P2 1 and the unit cell dimensions are: a= 6.5376(3)A b =1l.8766(10)A c = 13.5312(15)A. ~ = 91.197(12) 0 , P2l, v = 1050.39(15)A3 • z = 2.
f.L = 0 .64mm- 1 , radiation Cu ka.
The three-dimensional intensity data werecollected on an Enraf-Nonius CAD-4 diffractometer. The structure was solved bydirect methods using SHELXL-97 using full matrix least square refinement. Final
R = 0.0408 and WR = 0 .'1163 for 1888 observed reflection with I > 2cr(I). In thetitle compound the outer two six-membered rings are in chair conformations,while the central ring is in an 8~ . 9a-half- chair conformation. The five memberedring adopts 13,14-half-chair conformation. The pyridylmethylene has an E
configuration with respect to the carbonyl at position 17. The structure isstabilized by intermolecular 0-H ... N and 0-H ... O hydrogen bonds ·. The structure
and conformational features of the title compound will be discussed .
Email: Vasukee@yahoo.com

A4-22I

SYNTHESES, CRYSTAL STRUCTURES AND LOW TEMPERATURE MAGNETICSTUDY OF 'IWO METAL-ORGANIC COORDINATION 3D FRAMEWORKS BASEDON MIXED N-AND 0-DONOR UGANDS

Golam Mostafaa, Tian-Huey Lua, Tapas Kr. Majib, N. RayChaudhurib.
aoepartment of Physics, National Tsing-Hua University, Taiwan, R.O.C :, blndian
Association for the Cultivation of Science, Jadavpur, Calcutta-700032, India.
Currently, scientists have dedicated their efforts to the magneto-structural
studies on polynuclear complexes, aimed at understanding the structural andchemical factors that govem the exchange coupling between paramagnetic centersand bridging ligands to develop the magneto-structural correlation enabling thedesigned synthesis of interesting magnetic material. Research work using flexible
malonate dianion is of current interest due to its versatile binding modes. But thework containing this flexible 0-donor carboxylate ligand in combination with rigid
N-donor based organic spacer is scanty.
We wish to present here the syntheses , structural diversity and low temperaturemagnetic study of two novel 3D architecture of copper(II). [{Cu2(malb(pyz)}(H20lln(1) and manganese(Il). [Mn 2(malb(4,4'bipy)(H 20lln (2) [mal = malonate, pyz =pyrazine, 4,4'-bipy = 4,4'-bipyridine] . The low temperature magnetic study ofcomplex 1 shows ferro as well as antiferromagnetic interaction. The ferromagentic
interaction (J=+8.8cm-1) operates due to syn-anti carboxylate bridging mode of themalonate dianion and antiferromagnetic interaction (J' = -3.7 cm- 1) operates
between the pyrazine bridging part.
The low temperature magnetic measurement of complex 2 shows the weak
anitferromagnetic interaction (J = -0 . 19 cm-1). Crystal data: (1) Tetragonal, P4 2 1c,
a=b=12.5982(12),c=9.1858(l2)A, R=0.0305, wR2=0.0840, S=l.06. (2) Monoclinic ,P2 1 /n, a=7.2974(10). b=18 .7715(10). c=7.514(3). {3=91.743(12)0, R=0.0428,
wR2=0.1431, S=l.l2.
Email: mostafa@phys.nthu.edu.tw

A4-23

SELECTIVE PRECIPITATION OF POLYOXOMETALATE CLUSTERS BY ORGANICCOUNTERIONS: A SUPRA-MOLECULAR STRATEGY FOR CHEMICAL SYNTHESIS

Herman H-Y. Sung, Xiao-Yuan Li, Li-Rong Cai, Ian D. Williams and Samuel M-F.
Lo.Departrnent of Chemistry, Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong.
The modification of inorganic frameworks and structures by organic groups is wellestablished in the hydrothermal synthesis of open-framework and microporous
solids such as zeolites, in which the organic groups may serve as 'templates'.
Polyoxometalate clusters have been receiving increasing attention due to theirvaried physical, chemical and even biological activity. Herein we attempt to showthat organic counter-ions can also serve as selective crystallization tools for theseoxides, allowing the isolation of novel cluster anions in high yield and purity. In
the molybdenum-vanadium-phosphate system we report several new cluster
types. These include the reduced capped Keggin cluster [Mo 8V6 P0 42 ] 8 - which has
been isolated as its piperazinium and l ,4-diammoniocyclohexane salts. This isinteresting since the Mo and V sites are chemically ordered and have nominal
fractional valence states of +5.5 and +4.5 respectively. Initial studies on thephysio-chemical properties and REDOX behavior of these clusters will be
discussed, as will aspects of the supra-molecular assembly in the crystal packing
which influence the process of selective cluster precipitation.
Email : herrnans@ust.hk

A4-24

1HE HYDROTIIERMAL CRYSTALLIZATION OF ORGANIC COMPOUNDSIan D. Williams , Lo-Ming Lai, Samuel M-F. Lo, Fanny L-Y. Shek and John A. Cha.
Department of Chemistry, Hong Kong University of Science and Technology, Clear
Water Bay, Kowloon, Hong Kong.
The application of hydrothermal and related methodologies to the growth oforganic crystals will be discussed. The advantages include enhanced crystal size,
quality and high isolated yield. For co-crystals of different molecular species highphase purity and stoichiometric control can also be achieved. In the field of
natural product characterization the improvements in modern X-ray
diffractometry, combined with such new crystallization strategies , should see Xray diffraction play an increasing role. We present several examples from thisarea, including the anti-malarial drug artemesinin and its derivatives.
In the field of crystal engineering, hydrothermal methods can be used to form
organic co-crystals between aromatic acids and bases with specificstoichiometries so that molecular crystal 'phase diagrams' can be explored.
Stoichiometry control also has important structural consequences and various
bipyrtdines can form both a family of 1: l neutral molecular adducts with phthalicacid, as well as a 1:2 family of organic salts. The hydrogen bonding in thesecrystals is under supra-molecular control and give examples of crystals with short
single well N-H-0 hydrogen bonds, such as 2[4,4'-bipyH 0 .5 }[C6 H 2 -l,2,4,5-(COOk
H 3 ). Crystals suitable for neutron diffraction, including deuterated forms, arereadily formed by hydrothermal methods and allow new insights into thisimportant class of hydrogen bond .

Email : chwill@ust.hk

A4-25

PREPARATION, CHARACTERIZATION AND STRUCTIJRES OF COPPER(ll) AND
ZINC(ll) COMPLEXES OF AN ASYMMETRIC COENZ\'ME ANALOGUE

Xiaobai Wang, J ohn D . Ranford, Jagadese J Vittal". Department of Chemistry,
National University of Singapore, Singapore 117543.
Pyridoxal phosphate is a cofactor required by many enzymes for catalyzing aminoacid transformations. The reactions may involve the formation of an intermediate
Schiff base. A series of copper(II) and Zn complexes of the ligand N-(2pyridylmethyl)glycine, and N-(2-pyridylmethyl)-L-alanine, which were regarded as
analogues of pyridoxal phosphate have been synthesized and characterized. Five
single crystal structures were solved. It is clear that when the anions, which wereintroduced by the cop per(II) or Zn salt coordinated with the metal center, a linear
chain structure were obtained.

...

®

[ {Cu(pala)Cl }2]n- 1.5nH 20,[ {Cu(pala)(CH 3COO) }2]n-nH20[ {Cu(pgl y )Cl )2Jn- 2nH20

Email : chmjjv@nus.edu. sg

A4-26

EFFECT OF SUBS'ITIUENTS
1RANSFORMATIONS

ON

THE

SOLID-STATESUPRAMOLECULAR

Jagadese J. Vittal, Department of Chemistry, National University of Singapore,
Singapore 117 543.
Supramolecules are generally prepared by self-assembly. Transformation of one
type of network structure to another is very rare in supramolecular chemistry as
well as in crystal engineering. For the first time, we have reported that the dimer[Zn2(salab(H20hln.2H20 (sala = N-(2-hydroxybenzyl)-L-alanine) with cross-linked
hydrogen bonded helical porous honeycomb coordination polymeric network
structure, upon removal of water molecules by thermal dehydration resulted inanother 3D helical polymer, this time held by covalent bonds.

p={

Zn-r'~-~/flo-Zn~\o....L..-o,~er....._ _,
~\3

'o

6.
-

-2H20

71
::::-....

Thermal dehydration in a similar system, [Cu 2(salab(H 20lln with helicalcoordination polymeric structure results in the solid state supramolecularconversion to the chiral 3D covalent open network [Cu 2(salahln· The structure isisotypical to the Zn analogue. X-ray crystallography reveals that hydrogenbonding plays a key role in this process. These are the first examples of a true
'solid-state supramolecular synthesis' from two different precursors with two
different metals. We have also investigated the influence of the substituents ofthe backbone of the ligand N-(2-hydroxybenzyl)-L-aminoacid on the solid state
structures, and their dehydrated products. The results will be discussed in the
talk.
Email : chmjjv@nus.edu.sg

A4-27SYNTIIESIS, CHARACTERIZATION AND ANTIBACTERIAL ACTIVITY OF TilE
COMPLEXES OF METAL NTIRATES WITH SCHIFF BASE DERIVED FROM 4AMJNOANTIPYRINE AND TIIENOYLTRIFLUORO ACETONE

Jin-Ling Wang 1 , Ming Yul. 2 , Yun Yang 1 and Fang-Ming Miao 1 . 'College ofChemical and Life. Tianjin Normal University, Tianjin, 300074. P.R.China
2 University ofTianjin Light Industry, Tianjin, 300022,
P.R. China.
Metal complexes of Schiff base have occupied a central role in the development of
coordination chemistry. This is apparent from the large number of publications
ranging from the purely synthetic to modem physical and biochemical studies ofthese complexes.
New tridentate Schiff base ligand L 1 derived from the condensation of
thenoyltrifluoro- acetone with 4-aminoantipyrine has been synthesized andcharacterized on the basis of elemental analyses, IR and X-ray diffraction
methods. The structural analysis of this Schiff base ligand by X-ray diffraction
indicates that it is a neutral tridentate in the ketoenamine form. Complexes of thetype [M (LJlm (H20)nl (N0 3) s (where M=Ni2 +, Cu 2 +, Zn 2 +, m=l,n=l,s=2; when
M=La3+. Sm3+, Dy3+, Er3+, Nd3+, m=2,n=O,s=3) have been synthesized andcharacterized on the basis of elemental analyses, IR, DTA. The complexes havebeen screened for their antibacterial activities against two bacteria.

Fig I The Perspective Drawing of the Title Compound
Email: Wangjinling43@eyou.com

A4-28COORDINATION CHEMIS1RY OF SULFONATES:INVESTIGATION OF METAL ARENEDISULFONATESASYSTEMATIC

X-RAY

Jiwen Caia.b, Cai-Hong Chenb , Cheng-Zhu Liaob, Xiao-Ming Chenb.
alnstrumentation Analysis & Research Center. bSchool of Chemistry and Chemical
Engineering, Zhongshan University, Guangzhou 510275, P.R. China.
The coordination chemistry of metal sulfonates is not well explored and/or
rationalized , unlike that of metal phosphates, which are well studied. Owing to
the weak coordination strength of the sulfonate oxygen atoms toward the metal
ions, only a few structures of transition metal sulfonates with the so3- group thatform direct coordination with the metal ions, are available. For the purpose ofinvestigating the coordination chemistry of sulfonates , as well as the possibility of
constructing functional inorganic-organic lamella r materials derived from metal
disulfonates, the crystal structures of a series of metal arenedisulfonates were
investigated.
All the compounds were prepared in aqueous solution. For Group IA and IIA
metal 1,5-naphthalenedisulfonatesl. all except Mg2 + such as u+, Na+ , K+ , Ca2 +,Sr2 + and Ba2 + are coordinated by S0 3- and similar inorganic-organic layered
structures are adopted . For transition metal ions, Co3+, Ni 2 +, Cu 2 + and Cd 2 + form
aquametal compleXi cations segregated with sulfonate anions . However, afterincorporating amino ligands to the metal centers, so 3- is coordinated to Cu 2 + 2
and Cd 2 + 3 in aqueous solution, and !-dimensional polymers are constructed by
the chromophores [MN 4 0 2 ] 2 + with arenedisulfonates anions as bifunctiona lspacers.
1. J. Cai et al. Acta Cryst. Section B, 2001, B57, 520-530; 2. J. Cai et al. J. Chern.
Soc. Dalton Trans., 2001, 1137-1142; 3. J. Cai et al. J. Chern. Soc. Dalton Trans .,2001, 2370-2375.

Email : puscjw@zsu .edu.cn

A4-29CRYSTAL S'IRUCTURE OF BROMOMETIIOXY OSTIIOL (7--METIIOXY-8 (2BROM0- 3 -METIIOXYL 3-METIIYL-BUTYL) COUMARIN)
K. Anand Solomona, R. Malathia, S .S .Raj ana, Geetha Gopalakrishnanb,
V.Kasinathb,
anepartment of Crystallography and Biophysics, University ofMadras, Guindy Campus,Chennai-600025.India and bSPIC Science Foundation,
Guindy, Chennai - 600032.India.

Coumarins form an important class of widely distributed natural compounds .
Most of them are isolated from plants especially from the family Umbelliferea,
Rutaceae and leguminosae and also from animals or microorganisms. A wide
spectrum of biological activities of coumarins includes -antithrombic effect,
vasodilating effect on coronary vessels, reduction in blood pressure, antipastic
and photo sensitizing effects. Osthol is a naturally occurring compound isolated
from the seeds of Imperatoria Osthruthium. During the process of search forbioactive leads , Bromomethoxy Osthol was prepared by a facile, high yielding
reaction of Osthol with Polymer supported per bromide resin. The chemical
structure was assigned based on lD and 2D NMR studies. The crystal study was
conducted with an interest to check whether the compound was a rac~mic
mixture or a single isomer and if so to find the absolute configuration. The
compound crystallizes in triclinic system with 4 molecules in the unit cell and thecell dimensions were, a=l0.280(2JA. b=l0.497(4)A. c=l6. 175(4)A, a = 75 .91(2r,,8=80.81 (2)", y=68.00(3)". The structure was solved in space group Pl.However
latter it was found that there is a centrosymmetry between the molecules & hence
the origin was shifted to the point of centrosymmetry and the structure wasrefined with 2 molecules in the asymmetric u nit with space group Pl.The twomolecules differ in their conformations . The other structural details will bepresented .
Email: anand_solomon_20 00@yahoo.com

A4-30STRUCTIJRE OF 1,8-BIS[(3-FORMYL-2-HYDROXY-5-ME1HYL)BENZ"Y L]-1,4,8, 11A
12, 14-HEXAMETIIYLCYCW1ETRADECANE,
1ETRA-AZA-5,5, 7, 12,
MACROCYCLIC LIGAND

G. Senthil Kumara, N. Sengottuvelanb, D. Saravanakumarb, M. Kandasamyb,
K.Chinnakalia, Suchada Chantraprommac and H-K. Func, aoepartment of
Physics, Anna University, Chennai 600025, India; bOepartment of Inorga nic
Chemistry, University of Madras , Chennai 600025 , India and cschool of Physics ,Universiti Sains Malaysia, 11800USM, Penang, Malaysia.
Most of the naturally occurring enzymes been found to contain one or more metal
atoms in their active sites , which tremendously influence their biologicalactivities . As it is very difficult to study the biological activities of the naturally
occurring bimolecules, synthetic models of various systems have been prepared to
mimic the dexterous biological behaviour of the metal centers. The chemistry ofpolymacrocycles with coordinating side arms has attracted increasing interest
during the last decade due to their abilities as coordinating ligands . For example,
the synthesis of hexamethylated cyclam( 1,4,8, 11-tetraazacyclotetradecane)derivatives N-substituted by donor groups has been widely investigated . In fact
such a N-substitution onto a macrocycle may increase its selectivity towards
metal sequestration as well as the stability of the formed complexes. Moreover it iswell known that the trans substituted hexamethylated cyclam can lead to hexacoordinated complexes. The complexes may allow m a gnetic interaction or electrontransfer studies depending on the nature of the encapsulated cations . Conversely,
N,N'-disubstituted cyclams were far less studied due to their rather difficult
synthesis. Hence a new building block for the complexation which contains N,N'disubstituted (3-formyl-2 -hydroxy-5-methyl)benzyl group in the cyclam has b een
devised 1 . This system is found to contain both phenolic oxygen and imine
nitrogen group as donor centers, which have robust ligating nature for metal
coordination. The crystal of the above compound contains two half-molecules in
the asymmetric unit with the other half generated by a center of symmetry. The
two phenolic oxygen atoms lie on either side of the planar part of the macrocycle
at 2.321A. The structure is stabilized by N-H ... O and C-H .. .O hydrogen bonds .
1N.Sengottuvelan, D.Saravanakumar & M.Kandasamy (2001). Under preparation.
Email : kali@annauniv.edu

A4-31

AGGREGATION-CON'IROILED PROTON TAUTOMERIZATION

Keiichiro Ogawa and Jun Harada, Department of Chemistry, Graduate School ofArts and Sciences, The University of Tokyo, Komaba, Meguro, Tokyo, 153-8902
Japan.
Compounds that undergo proton tautomerization can be thermochromic, because
the tautomerization involves a proton transfer that accompanies a reorganizationof the relevant n-conjugated system. Salicylideneaniline (1) and its analogs belong
to a class of such compounds. In salicylideneanilines, the OH form is usuallymuch more stable than the NH form [equation (1)] and the population change ofthe two tautomers with variation of temperature has been regarded as the cause
for thermochromism. We found that in the crystals of 2, NH form ispredominantly zwitterionic and is considerably stabilized by intermolecularhydrogen bondings and electrostatic intermolecular interactions. The results
indicate that the assoCiation of molecules is essential for the stabilization of the
NH form .

(1 )OH form

NH form
1 :X= Y=H

2 :X= OH ,Y =CI

We discovered that, a major stabilization of the NH form generally occurs even ina fluid solution, when molecules form an aggregate. At 297 K, the OH form is
exclusively present. When temperature is lowered , the OH form decreases in
population and the NH form emerges. At 77 K, the NH form is exclusively present.
This phenomenon strongly depends on the concentration of the solution. The
results indicate the formation of aggregates at low temperature and thestabilization of the NH form in the aggregate. Thus, the proton tautomerization iscontrolled by the aggregation of molecules.
Email: ogawa@ramie.c.u-tokyo.ac.jp

A4-32CRYSTAL S1RUCTIJRE OF 2-N-BU1YL-4-CHLOR0-1[(2'-CYANOBIPHENYlr4YL)METIIYL]-5-HYDROXYMETIIYL IMIDAZOLE

P. Arnbalavanana, K. Palania, M.N. Ponnuswamya, B. Prabuswamyb, H. S .
Yathirajanb, C.R. Rajub and K. N. Mohanab, aoepartment of Crystallography andBiophysics, University of Madras, Guindy Campus, Chennai 600 025, India ,bOepartment of Studies in Chemistry, University of Mysore, Manasagangotri,
Mysore- 570 006, India.
The title compound is a white crystalline solid and serves as an important key
intermediate for preparing the antihypertensive drug Losartan potassium.
Imidazole part of losartan carrying substituents is the prime cause for the
antihypertensive property. It has melting point of 154°C, soluble in chloroform,
tetrahydrofuran, acetone, etc. The compound (C 22 H 22 0N3 Cl) crystallized intriclinic space group Pl with a=8.198(2). b=l0.997(3). c=ll.524(2)A. a=90.83(2).
0~=94 . 31(2). y=l09.45(2) and Z=2. The structure was solved by direct methods
and the final refinement was carried out with anisotropic thermal parameters
using full-matrix least-squares for all non- hydrogen atoms to a final R-value of
0 .0813 for 3827 unique reflections at 1>2 (I) collected using Enraf-Nonius CAD-4
diffractometer with CuKa radiation. The benzene ring containing Cl9 atom in thisstructure is approximately perpendicular to the imidazole ring. The structure isstabilized by 0-H .. . N, C-H ... N and C-H ... O types of intermolecular hydrogenbonds in addition to the van der Waals forces. The structure and conformationalfeatures will be discussed in detail.
E -mail : palamni_k@yahoo.com

A4-33
CRYSTAL S'IRUCTURE ANALYSIS OF 4-CHLOR0-3-METHYL-6[(N-2-PICOLYL)-l'IMINOME1HYL]PHENOIATO COPPER(II)PERCHLORATEK.Sarabojia, M.Kuppayeea. M.N.Ponnuswamya and Hoong-Kun Funb, aoepartmentof Crystallography and Biophysics , University of Madras, Guindy Campus,
Chennai - 600 025, India and bX-ray Crystallography Unit, School of Physics,
Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
Copper is the third most abundant element among the transition metal ionsfound to be involved in biological processes. The synthesis of mononuclear copper
complexes has been stimulated by a desire to 'mimic' the active sites ofmetalloproteins. The mononuclear Cu complex crystallizes in monoclinic spacegroup P2lfn with cell parameters a= 7.295(4). b = 19.627(5). c = 12.770(4)A and~ = 101.25(4) 0 • The structure was solved by Patterson's method by SHELXS97
program and refined by full-matrix least-squares technique using SHELXL97
program. The final R value is 0.0387 for 2906 unique reflection in the I > 2 cr (I)cut off range. The copper atom coordinated to oxygen and nitrogen atoms found tohave a slight distorted square planar geometry. The six membered ring containing
Cu and 016, atoms assume sofa conformation and the five membered ring
containing Cu and N15 is planar and lie in the same plane with the picolyl ring.
The negative cha rge in the perchlorate molecule is neutralized by protonation in
the methoxy group. The molecules are packed in a discrete fashion with and 0 H ... O and C-H ... O types of intermolecular interactions playing a major role instabilizing the molecules.
Email: ksaraboji@rediffmail.com

A4-34
CRYSTAL STRUC'IlJRE OF TRICOSANE-1, 23-DIOL

K. Unoa, N. Nakamuraa and Y. Ogawab, aoepartment of Applied Chemistry,

Faculty of Science and Engineering, Ritsumeikan University, 1-1-1, Nojihigashi,
Kusatsu , Shiga 525-8577 , Japan, and bOepartment of Chemistry, Faculty of
Science, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555, Japan .
The crystal structure analysis of tricosane-1, 23-diol, HO-(CH 2 h 3 -0H. was carriedout by single crystal X-ray diffraction method. All measurements were made on a
Rigaku AFC-5R diffractometer with graphite monochromatized Cu Ka radiation.
The crystal structure is an orthorhombic system (a=7.230(6)A. b=63.045(5)A,
c=5 .041(4)A, Z=4) with a space group ?2 12 12 1 . All calculations were performed
using TEXSAN. The structure was solved by direct methods with SAPI 91. The
methylene H atoms were located at idealized positions, and were allowed to rideon the parent C atoms (C-H=0.95A). The hydroxy H atoms were located from adifference Fourier map, and were allowed to refine isotropically for the final
refinements. All H-atoms isotropic displacement parameters were fixed at l.2Ueqof the parent atom. The final cycle of full-matrix least-squares refinement was
based on 2491 observed reflections (F'2>-3cr(F'2)). The refinement was concluded
with fmal reliability factors R(F'2>2cr(F'2))=0.047, wR(F'2)=0.176. In the molecular
structure of the title compound, one of the hydroxy groups has a gauche
conformation with respect to the hydrocarbon skeleton, whereas the other has atrans conformation. The molecules arranged along the longest axis, b. form layers
which are similar to those of the smectic A liquid crystals.
Email : rc002961 @se.ritsumei.ac.jp

A4-35
CRYSTAL AND MOLECUlAR S1RUC11JRE OF 2,6, -DI (2,3,4,- TRIMETIIOXY)
BEN~ENECYCLOXANONE

C.Choodamania, Vasub, M. Srinivas Murthyc, S.Mohanc and K.A. Nirmalad.
(a)Department of Physics , Govt. Science College, Bangalore- 2 . (b]Department of
Physics, Vivekanada degree College, Bangalore -55, [c] Department of Pharma
Chemistry, Al-Ameen College of Pharamacy Bangalore-27, [d] Department of
Physics, Bangalore University, Bangalore -56 .
The title campound C26 H 30 0 7 is a new chalcone and it will be used as starting
material for the synthesis of novel derivatives of 1,3-thiazines. These areimportant class of hetrocyclic compounds having diverse biological activities suchas antibacterial. antifungal, insecticidal, anthelmintic and anticonvulsant
The title compound crystallises in orthorhombic system, space group Abm2 with
a=8 .704(1), b=38.140(7), c=6 .945(3)AO, V=2305A03 Z=4, T=293K, A. =0.71073Ao, f-l=0 .095mm- 1 , F(000)=968 , Dc=l.309mgjm3 . The intensity data were collected .
from the Enraf-Nonius CAD-4 diffractometer. The structure was solved by direct
methods and refined by full matrix least squares on F 2 to a final R value of 0.0377
and WR2 value of 0 . 1105 for 1037 reflection with I > 2 sigma (I) . The structure isstabilized by hydrogen bonds in crystal packing. The structural aspects of themolecule will be discussed in detail.
Email: nirmalaka47@ Yahoo.com

A4-36
CRYSTAL STRUCTURE OF N (3', 4', 5'-TRIME'IHOXY BENZYLIDENE)-3-CHLOR04-FLUORO.ANILINE N-OXIDE

K.V. Aijuna Gowdaa, M.K. Kokilaa, Puttarajaa and M.V. Kulkamib aoepartrnent of
Physics, Jnanabharathi Campus, Bangalore University, Bangalore-560 056, India
and bDepartment of Chemistry, Kamataka University, Dharwad-580 003, India.
The title compound crystallises in monoclinic space group P2Ifn, With
a=7.0843(6}, b=8 .3236(6}, c=26.1306(6) A, ,8=91.253(5)', Z=4, V=l540.47(9) A3 ,T=293(2) K, ). = 1.5418A. tt =2.463mm-l, F(000)=680, Dx=l.413mg/m3,
R=0.0517 , Rw=0.1614 for 2487 reflections, with I>4 (I) . The 3d-intensity data
were collected from the CAD4 diffractometer and the structure was solved bydirect methods and refined by full matrix least squares method using SHELXL-97
program. The three methoxy groups attached to the other phenyl ring have large
deviations from the mean plane of the ring making the molecule on the whole
non-planar. There are no inter molecular hydrogen bonds and the structure isstabilised by van der Waals interactions.
Email: m:junagowda@indiainfo.com

A4-37

X-RAY CRYSTAL STRUCTIJRECHLOROBENZOIC ACID

OF

TRIPHENYLPHOSPHINE

OXIDE

Khalid A. Al-Farhan, Department of Chemistry, College of Science, King
University, P.O . Box 2455 , Riyadh 11451 , Saudi Arabia.

M-

Saud

Hydrogen bonds play an important role in many systems. This is mainly due totheir strong directional interaction compared to other intermolecular forces . Suchhydrogen bonding property has been utilized in molecular recognition and crystal
structure engineering. Triphenylphosphine oxide (TPPO) has a great
conformational flexibility and hydrogen bond formation ability, which makes it aversatile molecule for cocrystallization. As part of our research interest in theabove system, X-ray crystal structure of the title compound has been
investigated.
C2sH2oClOsP. Mr 434.83, Monoclinic (P2Jin); a = 8.845(1). b = 16.101(1). c =16.029(2) A, {3 = 103.97(1) 0 , V = 2215.3(4) A3, Z = 4, Deale. = 1.304 g cm-3, A.(MoKal = 0.71073 A, f.-L = 0 .268 (mm- 1). R = 0.042 for 3334 reflections and 280
parameters.
In our contribution, details of the crystal structure will be reported and the typeof hydrogen bond and its effect on

TPPO conformation will be discussed.
Email: alfarhan_k@hotmail.com

A4-38NOVEL COORDINATION POLYMERS CONS'IRUCTED FROM 4,4'-BIPYRIDINEAND PHOSPHATE

Kwang-Hwa Lii, Department of Chemistry, National Central University, Chungli
and Institute of Chemistry, Academia Sinica, Taipei, Taiwan, R.O .C.
The synthesis of open-framework metal phosphates has been a subject of intense
research owing to their interesting structural chemistry and potential applications
in catalysis. Recently, many research activities have focused on the synthesis of
inorganic-organic hybrid frameworks. A study of the literature about transition
metal supramolecular architectures shows that the most extensively studied
bridging organic ligand is 4,4'-bipyridine. The results presented here concern
several novel compounds in the metal-phosphate-4,4'-bpy system. For example,
the structure of (4,4'-H 2bpy)[V2(4,4'-bpy}z(HP0 4)4] consists of phosphate-bridged
vanadium(III) chains, which are linked through 4,4'-bpy ligands to form anionic
sheets with the charge compensating uncoordinated (4,4'-H 2bpy) 2+ cations
between the sheets . [Ni(4,4'-bpy}z(H 2P0 4}z]·C4H 9 0H-H20 exhibits a new type ofinterpenetration involving a 2D square net and a 3D CdS0 4-type framework of thesame chemical composition. The structure of [(V0 2}z(4,4'-bpy) 0 .5 (4,4'Hbpy)(P04)]·H20 consists of phosphate-bridged vanadium(V) double chains linked
through 4,4'-bpy ligands to form a sheet with the monoprotonated 4,4'-Hbpy+
ligand being coordinated to the metal atom as a pendent group . The synthesis andcrystal structures of these novel compounds will be presented .
E-mail: liikh@cc.ncu.edu.tw

A4- 39FROM 5,1'-DICY CWPENTADIENETRIENE SKELETONSKELETON

TO

SPffi0[4,5]DECA- 1,6 ,8 -Ling-Kang Liu and Lung-Shiang Luh, Institute of Chemistry, Academia Sinica,
Nankang, Taipei, Taiwan 1 1529, Repu b lic of China.
Utilizing a strategy of electron-transfer chain catalysis followed by nucleophilica lkylation, (Y] 4 -exo-5-(C 5 H 5 )C 5 H 5 )Fe(CObPPh 3 (1) was obtained in 6 0% isolated
yield starting from (Y] 5 -C 5 H 5 )Fe(CObi , PPh 3 , and C 5 H 5 Li. Normally the en do
hydride of similar compounds could easily be abstracted by Lewis acid [Ph 3 C+] or
pro tic acid HBF4 and accordingly a treatment of [Ph 3 C+] on 1 was expected toresult in [(Y] 5 -(C 5 H 5 )C 5 H 4 )Fe(CObPPh 3 +] (2). However, th e reaction with [Ph 3 C+]
didn 't give 2 but [(Y] 5 -spiro[4,5]decatrienyl) Fe(COhPPh 3 +] (3) . Cation 3 , upon anucleophilic
attackby
C 5 H 5 Li,
gavea(C 5 H 5 )-derived(Y] 4 -

r::ts~

Ph 3C+~

H~
oC"'"" J e....__ PPh3
oc
1

2

The X-ray structure analysis of 4 gave clearly the molecular connectivity that
retrochemically suggested an unprecedented transformation from 5, 1'-dicyclopentadiene skeleton to spiro[4,5)deca-l ,6,8-triene skeleton.

Email: liuu @chem.sin ica.ecl u.tw

A4-40IN1ERMOLECULAR IN1ERACTIONS EXAMINED BY

S1RUCTURAL CHANGESOF MIXED CRYSTALS.

M. Yasui, R. Miki, N. Takashima, D. Hashizume, and F. Iwasaki, Dept. of Appl.
Physics and Chemistry, The Univ. of Electro-Communications. Chofu, Tokyo 1828585, Japan.
It has been revealed that crystals of 4-(4-X-Ph-CH=N)-TEMPO radicals (X= Cl, Br
and Me) were crystallized into different forms and showed different magnetic
interactions . Crystals of the Br-derivative showed polymorphism with Cl- and Brforms. To examine the role of the substituents on the crystal packing-mode, we
prepared two-component mixed crystals (Cl-Br, Cl-Me, and Br-Me) and comparedstructural changes as the ratios of the components. Crystal structures of themixed crystals are isomorphous with those of either pure component. For Br-Me
system, mixed crystals of Me-, Br-, and Cl-forms were obtained. From thechanges of the intermolecular interactions and the comparison of the polymorphic
forms of the Br derivative, it was suggested that an intermolecular Br- · ·Br
interaction is very important for the crystal packing.
The electrostaticinteractions of the substituents and n-n interactions of phenyl rings are also
important for the packing mode . Intermolecular energies were calculated using
simple force-field potentials for the X· ·Y (X, Y=Cl, Br, Me) molecular pairs andAryl-Aryl stacking pairs in the mixed crystals of Br- and Cl-forms. These
calculations partly support the observed ratios of components.
Email : yasui@pc. uec.ac.jp

A4-41SYNTHESIS AND S'IRUC'IURE OF 4,4,4-TRIFLUORO- 1-(2-THIOPHENE-2, 3BUTANEDIONE-AMINO- AN11PYRINE SCHWF BASE

Sun Ming 1 , Zhang Xinl, Jin-Ling Wang 1 , Ming Yu2 and Fang-Ming MiaoL ·'College
of Chemical and Life, Tianjin Normal University, Tianjin, 300074, P.R.China.
2University ofTianjin Light Industry, Tianjin, 300022, P.R.China.
Schiff base compounds derived from large numbers of carbonyl and aminecompounds have been investigated, since they are becoming increasingly
important as biochemical, analytical and antimicrobial reagents. The crystal dataof the title compound is as follows : a= 10.964(3) . b = 12.570(3), c = 13.840(4), 13 =96.822(5) 0 , monoclinic, space group P2Ifc, Z = 4, F (000) =864. De = 1.478g cm-3 ,Jl =0 .226 mm- 1 . The fmal refinement converges to R = 0.0546 on F 2 , withthe goodness - fit - of 1.046. The highest and lowest electron densities in the final
difference Fourier map were 0.499 and -0.388e A- 3 .
The molecule consists of the pyrazolone, thioplene, phenyl .rings andtrifluoropropane- dicarbonyl moiety (see Fig 1). The bond lengths of C (6) -N (3), C(8) -0 (1) and C (7)-0 (8) ;;rre 1.274(4), 1.219(3) and 1.204(3) A, respectively,
corresponding to the -C=N and cC=O bond lengths . but the bond lengths of C (6)-C(7) and C (7)-C (8) are 1.534(3) and ·1.529(3) A respectively. corresponding to thesingle C-C bond length, pointing to no extensive electron delocalization·· over themoiety.
.

Fig 1 The Perspective Drawing of the Title Compound
Email: mingswan@yahoo.com

A4-42

ROLE OF HALOGEN· BONDING .I N FORMATION OF STABLE IN.C LUSIONCOMPLEXES: X-RAY S1RUCTIJRES OF MYO-INOSITOL DERIVATIVES WTIH
DIHALOMETHANES (CH2X2, X= Cl, Br)

R. G. Gonnade, K. M . .Sureshan, . M. S. Shashidhar and M. M. Bhadbhade.
National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411 008, INDIA
Inclusion complexes with high selectivity for guests is a frontier research area
because of its applications . in molecular selectivity and separations. However,designing .a host that exhibits a specific molecular recognition capability is achallenging task. In a s~rendipitous discovery, a spontaneous crystallization of
racemic 1,2,3,4,5 penta-0-benzoyl-6-0-tosyl myo-inositol (1) derivative yielding
highly stable inclusion crystals was observed only with dihalomethanes (CH2X2 ,X=::Cl., Br). whereas other common solvents failed to give crystals.
X-ray
structures revealed that the guests were held essentially by shqrt C-X ... O contacts
and C-H ... O interactions (Fig. 1).1 In order to assess the role of former interaction
termed as halogen bonding2 in stabilizing host-guest complexes, a few more myoinositol derivatives were synthesized . In this paper, we report two structures ofhexa-0-benzoyl-myo-inositol (2) with dihalomethane guests (CH2X2, X=Cl., Br) .
Packing of molecules show (Fig. 2) two different types of open channels eachcontaining molecules of CH 2X 2 . Guest molecules in one of the channels makeessentially strong C-H ... O contacts while those in the other make X ... O contacts
with the host which are weaker than those observed in (1) 1 . But remarkably, here
again, the spontaneous crystallization of (2) occures only with CH 2 X2 , although
the inclusion crystals of (2) are highly unstable to open atmosphere compared tothe stable crystals of (1) . The role of C-X ... O interactions in the formation of guest
specific stable inclusion complexes will be: discussed with reference to the above
crystal structures and others analyzed from the Cambridge Crystallographic Data
Base.

Fig. I

Fig. 2 (for CH2Cl2)

Reference:
1 K. M. Sureshan, R.G. Gonnade, V. G. Puranik, M. S. Shashidhar and M. M.
Bhadbhade, Chem.Commun., 2001, 881.
2 E . Corradi, S. V. Meille, M. T. Messina, P. Metrangolo and G. Resnati, Angew.
Chern. 'Int. Ed. 2000, 39, 1782.
Email : mohanb@sil.nd.res.inA4-43

STRUCTURAL INVESTIGATIONS ON METAL PHOSPHONAffiS

Mrinalini G. Walwalkar, Department of Chemistry, Indian Institute of TechnologyBombay, Powai, Mumbai-400 076, India
Interest in transition metal phosphonate chemistry has accelerated in the recent
years owing to their potential uWity as sorbents and catalysts . We have recently
synthesized some metal phosphonates using cyclohexyl phosphonic acid
(CyP0 3 H 2 ). The reaction when carried out in different conditions such as,hydrothermal, microwave as well as by slow crystallization, resulted in the same
divalent phosphonates h aving a general formula of MII(0 3 PR).H 2 0, (R= cyclohexyl) .
Analytically pure products were obtained in each case and were characterized byIR, DRUV, TGA/DTA, microscopy. and powder XRD methods. Representative
examples were also studied by single crystal X-ray diffraction studies. The
thermal analysis shows the removal of a water molecule and finally the formationof metal phosphate materials. The details of this investigation will be discussed inthis presentation.
Email : mmm@chem.iitb.ac.inA 4-44
CRYSTAL STRUCTURES OF 6-SUBSTITUTED DffiENZO[d,g][ l,3 ,6 ,2] DIOXATillO
PHOSPHOCIN DERIVATIVES CONFORMATION OF HETEROCYCLIC RING.

M. Krishnaiah and N. Jagadeesh Kumar, Department of Physics. S.V. University,
Tirupati-517502 .
Organophosphorus heterocycles containing suitably substituted Phosphoryl unit
exhibit significant Physiological activity depending on their size, the magnitude ofthe electrophilic character of phosphorus atom. the strength of the bond p-x andstearic nature of the substitutents. These compounds find very wide applications
as pesticides , insecticides , nerve gases, antioxidants and as stabilizers in polymer
and oil industries.
The structural investigations of four 6 substituted
dibenzo[d ,g )[ 1,3,6.2) dioxathiaphosphocin derivatives have been studies tounderstand the influence of the substituents on the conformation and identity the
biological active phosphorus activities.
Crystal data:
I. C20 H15 Cl203PS2, monoclinic P21/c. a =13.272(2). b=9 .225(1). c=17.257(1)A(=90.39(1) 0 , Z=4, F(000)=960, dc=l.47Mg.m-3 , R=0 .035 and Rw=0.083 for 2874
observed and 3153 collected reflections.
II . C20H15Cl203 PS2, triclinic, P-1, a =7.845(3). b = ll.720(2). c=1l.871(2)A(=88.85(1). (=73 .6 1(2). (=89 .08(2) 0 , Z=2, F(000) =480, dc=l.489Mgm-3, R=0.0345
and Rw=0 .0835 for 2701 observed and 2896 measured reflections .
C16H14Cl403
PSN,
monoclinic,
P21/c,
a=9. 188 (2).
b =20.588(5).
III.
c= 10.861(3)A. (=102.55(2)0 , Z=4, F (000)=960, dc= l.567Mgm-3 , R=0 .0343 a nd
Rw=0.0875 for 3137 significant reflections.
IV. C13Hl503 PS, monoclinic, P21/n, a = ll.624(7). b = ll.091(3). c=14.407(4JA.
(= 107 .88(3)0 , Z=4, F(000)=896, dc=l.70 Mgm-3 , R=0 .045 and Rw=0 .109 for 2525
reflections.
All the structures are solved by direct methods and refined by full matrix leastsquares method. In the first three structures, the 8 -membered dioxathia
phosphocin r ing adopts a boat-chair (BC) conformation and the substituents arein axial and equatorial positions at P, whereas, in the fourth structu re, theheterocyclic ring exhibits a twist boat (TB) conformation. The geometricalparameters and orientations of the substituents at P will be discussed.
Email : dmjkumar@yahoo.co.inA4-45IN SITU OBSERVATION OF FLIP MOTION OF VINYL GROUP IN S1YRENEDERIVATIVE CRYSTALS

N.Yasuda, H.Uekusa and Y.Ohashi, Department of Chemistry and Materials
Science, Tokyo Institute of Technology, 12-1, 0-okayama 2-chome, Meguro-ku,
Tokyo 152-8551, JAPANStyrene is one of the most widely used materials in synthetic polymer science. Its
structure has been studied widely by theoretical calculations, but no crystal
structure has been reported so far. However. a crystal structure of styrene would
be very useful to understand its chemical properties and would also enable a
comparision with the theoretically derived structure.
Single crystals of styrene (C 8 H8 : m.p.242.5 K) and 2,4,6-trimethylstyrene (C 11 H 14 :m.p.236.2 K) have been made by in situ crystallization method, a nd theirstructures were determined by single crystal X-ray diffraction analyses at several
temperatures. For comparison, crystal structures four other styrene derivatives,
which are solid at room temperature, were also determined. In styrene 2,4,6trimethylstyrene and 4-vinylbenzoicacid (C 9 H 8 0 2 ). a disorder where the vinylgroup was fliped to the .opposite direction was observed. As the occupancy factor
changes with temperature, this flipping disorder was found to be the dynamical
thermal motion. In 2,4,6-trimethylstyrene, space group was changed from C2/ c to
P2If c between 173K and 153K.
By comparing crystal structures of disordered and ordered styrene derivatives,
the nature of the flipping motion of vinyl group can be clearly explained in termsof the environment around vinyl group, i.e. shape and volume of space occupied
by vinyl group.
E-mail: nyasuda@chem. titech.ac.jp

A4-46

MOLECULAR STRUCTURE OF DI-NUCLEAR Ni-COMPLEXES AS THE MODEL OF
UREASE ACIVE SI'IE

Nobuko Kanehisaa, Yong Xiea, Heitaro Yamaneb, Yasuo Nakaob, Yasu shi Kaia .
aDepartment of Materials Chemistry, Faculty of Engineerin g, Osaka University,
Suita, Osaka 565 -087 1 Japan, and bCh emical Laboratory, Faculty of Education,
Okayama University, Okayama 700-8530, Japan
Urease catalyzes the hydrolysis of urea, an abundant end product of metabolism,to form ammonia and carbon dioxide . So far, so many investigations of theactivity of urease and structural studies of the complex relevant to urease active
site have been under taken to elucidate the mechanism of urease catalysis . It has·been reported that for the activity of ap-urease, the adoption of carbon dioxide isessential in th e presence of Ni ions, and th at two Ni ions are 3.5 A apart.
We carried . out th e X-ray structural analysis of di-nuclear Ni-complexes; [Ni2 (LEt)(CHF2COO)(CH30Hb)(Cl04b (1) and [Ni 2(L-Et)(CF3COO)(H20b)(Cl0 4b (2 ) (HLEt = N, N, N', N'-tetrakis[l-ethyl-2-benzimidazolyl)methyl]-2-hydro xy- l , 3diaminopropane ) as the model of urease active site, to stu dy the urease catalysis
in more detail. Complexes 1 and 2 are isostructural. For 1 and 2 , each nickel
center has an octahedral geometry with an N30 3 donor set from a bridging
difuluoroacetato (for 2 , trifuluoroacetato). a lkoxo of L-Et, methanol molecule (for2 , H 20 molecule). tertiary amino nitrogen and two imidazolyl nitrogens of L-Et.
The alkoxo oxygen atom bridges the comer of the two octahedrons. The Ni --- Ni
distances are 3.542(2) A and 3.545 (1) A for 1 and 2 , respectively.
Email : kanehisa@chem .eng.osaka-u.ac.jp

A4-47

CRYSTAL AND MOLECULAR S'IRUCnJRE OF A COMPLEX: RHODIUM(ll1)(1,10-PHENANTIIROLINE)-(1,3-bis(BENZIMIDAZOLYL) BENZENE.

Noor Shahina Begum.* K. Jayalakshmi, N.M.Nanje Gowda, V.Gayathri,
P.Venugopalana. Department of studies in Chemistry, Bangalore University,
Central College Campus, Bangalore 560 001, India. aDepartment of Cemistry,
Punjab University,Chandigarh-160 014.
N-heterocycles undergo cyclometallation to give five membered metallocycles .
Cyclometallated complexes are used in organic synthesis, asymmetric synthesis,
homogeneous catalysis, liquid crystals and photochemistry.
X-ray crystal structure of the title compound has been determined. The
compound crystallizes in monoclinic spacegroup P2Ifn with cell parameters a=16.165(2) A b =11.377(2) A, c =16 .998(2) A.,B=92.35(l)O, z =2 and V=3123.46A3.
The structure was solved by direct methods using SHELXS-97 and refined by fullmatrix least- squares method using SHELXL-97 program. The final R-value is0.0268 for unique 4365 reflections with 1>2cr(I) collected using Siemens P4
diffractometer.
The 2D NMR experiments on the above complex showed unidentate binding
nature of 0-phenanthroline. However, such a possibility was ruled out from thecrystal structure analysis as it has established the bidentate binding mode of 0phenanthroline.The details of the crystal structure will be discussed.
Email: noorsb@vsnl.in

A4-48MOLECULAR
CRYSTAL AND
PHENYL)BENZIMIDAZOLESTRUCIDRE.OF

2-(2l_N-O-PYRIDYLIDINE-

Noor Shahina Begum.* K. J ayalaksmi, N.M.Nanje Gowda, V.Gayathri,
J.Shashidharaprasad a, M.A.Sridhar, a C.Devarajegowdaa . Department of studies
in Chemistry, Bangalore University, Central College Campus, Bangalore 560001 ,University,
Chemistry,Mysore
instudiesof
aoepartment
India.
Manasagangothri,Mysore,India.
X-ray crystal structure analysis of the title compound has been determined. The
compound crystallizes in monoclinic spacegroup P2 1 /cwith cell parameters a=8.6966(85)A b =1 3.0455(95)A. c =13.2707(41)A. ,8=97 .3822(44) 0 · z =2 and
V=l493.10A3 . The structure was solved by direct methods using SHELXS-97 andrefined by full-matrix least- squares method using SHELXL-97 program. The
final R- value is 0.1505 for unique 2047 reflections with I>2cr(I) collected using
Rigaku AFC7S diffractometer with MoKa radiation.Further refinement is underprogress.The details of the crystal structure will be discussed
Email: noorsb@Vsnl .inA4-49CRYSTAL STRUCTURE-REACTIVTIY CORRElATION METHOD: SOLID STA'IE
PHOTOCHEMISTRY AND
X-RAY CRYSTALWGRAPHY OF 6-HYDROXYCYCWDECANONE

Preeti Walia, Harjinder Singh, Tejvir Singh and P .Venugopalan , Department ofChemistry, Panjab University, Chandigarh, 160 014, India.
Solid state irradiation of 6-hydroxycyclodecanone (1) leads to a major
photoproduct, namely trans -9 , 10-decanediol (2) and its diastereomer, cis-9 , 10decanediol (3) (minor product). X-ray structural investigations of (1) and (2 ) were
undertaken to understand the product formation and the role of the specificcrystal packing that leads to the observed photoproducts . Crystal data: (1),
Monoclinic, P2 1 , a =7 . 169(1), b=5 .331(1), c= l2.509(l)A, ~=92 . 02(1) 0 , Z=2,
R=0.0302 for 936 observed reflections [1>2a(I)) . Crystal structure analysis reveals
that there are two possible hydrogens at y-positions that may be abstracted , but
the product formed is due to w-hydrogen abstraction. However the geometricalrequirement for this hydrogen to be abstracted is very severe. The productformation may be rationalized on the basis of a 1 ,4-biradical formation due to yhydrogen abstraction and its rearrangement to 1,6-biradical that collapses to thephotoproducts. Details of the structure, reactivity and packing will be presented.
Email : venu@pu.ac.in

A4-50SUBSTinJENT EFFECT ON THE CONFORMATION OF 1,5-BENZOTHIAZEPINEDERIVATIVES: CRYSTAL AND MOLECULAR STRUCWRE OF 2,3,4,51ETRAHYDRO-R-2, C-4-DIPHENYL-1,5-BENZOTHIAZEPINE(1) AND N-Nl1RpS02,3,4,5-1E1RAHYDR0-2,2',4-TRIMETIIYL-1,5-BENZO THIAZEPINE(2).

Parthasarathi Laavanyaa, Krtshnaswamy Panchanatheswarana, Manivannan
Krause Bauerb,
Muthukumara, Ramasubbu Jeyaramana. Jeanette A.
aoepartment of Chemistry, Bharathidasan University, Tiruchirappalli - 620 024,
Tamil Nadu, India, bOepartment of Chemistry, University of Cincinnati,
Cincinnati, OH, 42221-0172, USA.
As confirmed by X-ray analysis, the molecule 1 adopts a twist boat conformation
with the pairs of atoms N5, Cll and S1, ClO are oppositely oriented with respect
to the C2-C3-C4 plane. The conformation of the molecule of 2 is best described
as a boat with the four atoms, C2, Sl, C4 and N5 lying on a plane . The torsion
angles of the bonds of the seven membered ring also suggest a boat conformationin 2, with significant torsional distortion around S1-C2 bond. The S1 ···N5
intramolecular distances in 1 and 2 are found to be 3.220(2)A and 3.007(3)A.
respectively. There is a significant intramolecular C-H- ··0 interaction involving theatoms, C4 and 013 in 2 , which may favor the syn orientation of the nitroso groupwith respect to the N5-C4 bond. The equatorial orientations of the two phenylgroups and the C4-methyl group in 1 and 2, . respectively, are deduced from thecorresponding torsion angles. The diequatorial orientations of the two phenylgroups in 1 confirm their cis configurational dispositions. The presence of thenitroso group in the predominant polarized form in 2 is evident from the N5-N12
and N12-0 13 bond lengths with the N-N=O moiety being non-coplanar with the
fused benzene ring.
Email: laav@bdu.emet.in, laav74@yahoo.com

A4-51EXTENDED MET.AirORGANIC NE'IWORKS: A DETAILED X-RAY STRUCTIJRALINVESTIGATION
R. Murugavel, Department of Chemistry, Indian Institute of Technology-Bombay,
Powai, Mumbai-400 076, India

There has been a recent upsurge in the synthesis of coordination polymers , which
are based on multifunctional ligands because of the ability of some of thesepolymeric materials to form open framework metal-organic microporous materials.
Especially, recent studies have shown the use of divalent transition metal ionsand benzene di-, and tricarboxylic acids as modular precursors in designing
numerous metal-organic polymeric solids with desired topologies. Particularlyinteresting are the complexes formed by H2 BDC and H 3BTC having onedimensional polymeric chain or brick-wall structures and their selective guest
binding abilities. We recently investigated the extended solid forming ability ofboth H3BTC and H 4 BTEC towards divalent first row transition metal ions, such as
Co 2+, Ni2+ and zn2+ in the presence of a donor amine. The results obtained bysingle crystal X-ray diffraction studies on the products of these reactions will be
described in this presentation. In addition, structural studies on the interaction ofalkaline earth metal ions with aromatic amino carboxylic acids will also be
discussed.

Email : rmv@chem.iitb .ac.in

A4-52CRYSTAL ENGINEERING DESIGN OF NEW CI.A1HRA1E COMPOUNDS

Solhe F. Alshahateet, Roger Bishop, Donald C. Craig, Christopher E. Maijo. A.
Noman M.M. Rahman and Marcia L. Scudder, School of Chemistry, The
University of New South Wales, Sydney 2052, Australia.
Clathrate compounds arise from multiple interactions between two different typesof molecules packed together in a crystal lattice. We have devised a modular
method, which permits simple syntheses of new clathrate hosts from readily
available precursor molecules. The crystal engineering concepts behind this
synthetic approach will be explained . Families of new inclusion hosts have beenobtained successfully through variation of the molecular building blocks. In the
resulting inclusion compounds host, and guest molecules interact through a
combination of weak intermolecular contacts such as aromatic face-face, aromaticedge-face, halogen-halogen, and C-H ... N hydrogen bonds. Since the molecules areallowed to select the best combination of these weak interactions a wide range ofinclusion structures i~ obtained . The X-ray structures of a number of thesecompounds will be presented. These will be described in terms of the designconcept and the intermolecular contacts of most importance in determining theclathrate structures.
Email : r.bishop@unsw.edu .au

A4-53

CRYSTAL S1RUCTURE OF A TRIDENTATE LIGAND

M.Kuppayee, S .M.Malathy Sony and M.N.Ponnuswamy, Department of
Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai- 600 025 , India.
Ligand design and construction are important aspects in controlling the structure
and reactivity in coordination chemistry. The different ligands containing metallic
centers are used as catalysts in the growth and development of metal-cluster
chemistry. The development of these ligands has led to the successful synthesis ofhomo and hetero nuclear metal complexes, which have found applications in thearea of biomimicry. The compound bis[(3,5-dimethyl,2-hydroxy)-2'-hydroxy-5'bromo)benzylmethylamine crystallizes in triclinic space group, P1 with cellparameters a= 5.228(1), b = 12.364(1), c = 13.234(1)A, a= 94.04(1), ~ = 95.72(1)andy = 95.90(1) 0 • The structure was solved by direct methods using SHELXS97
and refined by full-matrix least-squares methods using SHELXL97 program to a
final R-value of 0.0508 for 3810 unique reflections . The two phenyl rings areplanar and orients at an angle of 53.9(2) 0 with each_ other. The nitrogen atomshows pyramidal character. In the ligand 0-H ... N and 0-H ... O types of hydrogenbondings are useful in stabilizing the molecules in the unit cell in addition to vander Waals forces. An intramolecular 0-H ... N type of hydrogen bond is observed
between the atoms 017 and N8 .
Packing shows that the symmetry-related
molecules are built up with respect to the symmetry axis and two moleculesinteract to form a closed ring.
Email: smmalathysony@yahoo.com

A4-54

CRYSTAL S1RUC1URE OF A DIMERIC MONONUCLEAR COPPER COMPLEX

S.M.Malathy Sonya, M.Kuppayeea, M.N.Ponnuswarnya, Hoong-Kun Funb,
J.Manonmanic and M.Kandaswarnyc, aDepartment of Crystallography andBiophysics, University of Madras, Guindy Campus, Chennai- 600 025, India, bXray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800
USM, Penang, Malaysia and cDepartment Of Inorganic Chemistry, University Of
Madras, Guindy Campus, Chennai - 600 025, India.
The behavior of multimetallic proteins and the metal-metal cooperativity lead to
distinct reactive patterns. The development of the chemistry of binuclear metal
complexes has been stimulated to investigate the mutual influence of two metal
centers in terms of cooperative effect on the electronic, magnetic and redox
properties of such systems. The present study aims to bring out the structuraland conformational features of N- [(2-hydroxylato- 5-methyl) benzyl- (2 ·-hydroxylato3',5'-dimethylbenzyl))ethylarnine dicopper(II) by using crystallographic methods.
The Cu complex crystallizes in Monoclinic space group C2/c with cell parametersa = 21.404(2). b = 13.962(1). c = 17.917(1)A and 13 = 124.394(2) 0 • The structure
was solved by patterson method and refmed by full-matrix least-squares
technique using SHELX97 package. The final R factor is 0.0882 for 5253 uniquereflection at I > 2 cr (I) cut off. In the complex, only one half molecule is present in
the asymmetric unit and the unit cell contains four molecules in dimeric form .
The complex has two solvent molecule, methanol and water, where the oxygen ofwater molecule occupies a special position and acts as an inversion center. The
copper atom has a slight distorted square planar geometry. The two six memberedrings containing the Cu atom assume distorted sofa conformation. The copper
nuclei are bridged by phenolic oxygen atom in a symmetrical manner. The
molecules in the structure are packed in discrete fashion with C-H .. . O type ofintermolecular interactions playing a major role in stabilizing the molecules in
addition to van der Waals interactions.
Email : smmalathysony@yahoo.com

A4-55
WA1ER - CHLORINE HYDROGEN BOND NE'IWORK IN A CRYSTAL STRUCTURE
OF NICKEL COMPLEX
R.A. Thirumuruhana. S.M.Malathy Sonya, M.N. Ponnuswamya, Hoong-Kun Funb,
J . Manonmanic and M.Kandaswamyc, aDepartment of Crystallography andBiophysics, University of Madras, Guindy Campus, Chennai- 600 025, India, bXray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800
USM, Penang, Malaysia and cDepartment Of Inorganic Chemistry, University Of
Madras, Guindy Campus, Chennai - 600 025, India.

Nickel enters the cell only by chronic exposure and Ni compounds containing
piperidine rings are strong carcinogens. Nickel (II) has been found to inhibit the
DNA repair mechanisms by interfering with enzymes or proteins involved in DNA
replication and/or DNA repair but the underlying mechanisms are unclear. In
order to understand this, the complex {4,4'-Dimethyl-6,6'-bis(piperidinomethyl)2,2' -(1,3-propanediylbis(nitrilomethylidene))
diphenolato-O,N,N',O'}nickel(II)dichloro hexahydrate was synthesized and there structural studies
carried out. The Ni complex crystallizes in monoclinic space group P2Ifc with cellparameters a = 9.5966(1) , b = 24.9070(1). c = 15.2625(2) A and ~ = 93.911(1) 0 •The structure was solved by Patterson method using SHELXS97 program andrefined using full-matrix least-squares method to a final R-value of 0.0661 by
SHELXL97 program. There are two chlorine ions in the lattice in order toneutralize the two positive charges of the complex and in addition, there are six
water molecules. The study of molecular features in the structure reveals aninteresting hydrogen bonding network between the six water molecules and thetwo chlorine ions.
Email: smmalathysony@yahoo.com

A4-56
CRYSTAL STRUCTURE OF AN ALKENE MONOMER

Sakuntala Guptaa, Guo-Ping Chang-Chienb, R.Centorec and S.P.Sen Guptaa ,aDepartment of Materials Science, Indian Association for the Cultivation of
Science, Jadavpur, Calcutta - 700 032. India, and bDepartment of Chemical
Engineering & Super Mass Research and Technology Center, Cheng-Shiu
Institute of Technology, Kaohsiung, Taiwan 833, R.O.C., and cDepartmento di
Chimica, Universitadi Napoli 'Federico II', Via Mezzocannone 4, 80134 Napoli,
Italy.
The crystal and molecular structure of the mesomorphic hydrocarbon monomer
3-[4-(4' -Ethylbiphenyl))-1-propene has been determined from X-ray diffraction
analysis at 293 (2) K. The compound crystallizes in the form of a non centrosymmetric monoclinic system. space group Pc, with two molecules per cell.
The cell parameters are a = 13.90 (5) A. b= 5.75 (1) A. c = 9.54(5) A and ~ =116.1(3) 0 • In this solution some constraints must be introduced and the atoms
have high thermal parameters but no evidence of disorder is present. The two
phenyl rings are nearly coplanar with a dihedral angle of 1.49 (4) 0 . Both of them
adopt boat conformations. The molecules are organised with their longest
extension in parallel sheets as observed from the packing in the unit cell. This
type of layered structure clearly indicates the smectic B phase of the title
compound. Since the compound does not contain any polar groups , thearrangement in the crystalline state is strongly dominated by repulsion potentials.
The length of the molecule in the crystalline state is 12.45 A. The layer spacing in
the mesophase has been obtained from X-ray diffraction pattern and was found to
be 12 .6 A. The layer spacing, comparable to the calculated length of the molecule,shows that the molecules form smecticB-like arrangement within the layers .
Email: mssg@mahendra.iacs .res.in

A4-57
S'IRUCTIJRE AND CONFORMATION OF 1-(4-METIIOXYBENZENE SULFONYL)-50XO-PYRROLIDINE-2-CARBOXAMIDE

Surajit Banerjee and Alok K. Mukherjee , Department of Physics, Jadavpur
University, Kolkata-700 032, India.
Oxo-pyrrolidine derivatives display biological activity as possible antineoplastic
and therapeutic agents. The structure and conformation of the title compound . anovel biologically active system containing an oxo-pyrrolidine moiety, has beenstudied by X-ray analysis and AM 1 molecular orbital calculations. The
compound, C 12 H 14 0 5 N2 S, crystallizes in the monoclinic system, space group P2 1with a=9.661(4)A. b=7 .246(3)A. c=11.378(5)A, [3=113.42(2) 0 , V=730.88(6)A3, Z=2.
The crystal structure has been solved by direct methods and refined by fullmatrix least-squares. on F 2 ,to R=0.044 for 1721 observed reflections with 1>2o(l).
The crystal structure consists of an essentially planar methoxyphenyl ring linked
to a 2-carboxamide substituted oxo-pyrrolidine moiety via a sulfonyl group and alattice water molecule. The oxo-pyrrolidine group has an envelope geometry. The
conformational analysis of the title compound investigated by semi-empirica lquantum mechanical AMI calculations shows a good agreement with the X-ray
structure excepting the carboxamide orientation. The results of X-ray structure
analysis revealed a rotation of the carboxamide moiety with respect to the AM l
optimised geometry by -60° about the C(oxo-pyrrolidine)-C(carboxamide) bond.
The molecular conformation and crystal packing of the title compound are
influenced by different types of hydrogen bonds. In the solid state, the molecules
translated in the b-direction are linked through NH·····O intermolecularhydrogen bonds to form an infinite one-dimensional chain.
Email: surajit@juphys.emet.in

A4-58SYN1HESIS,CRYSTAL

STRUCTURE

AND

1HERMAL

PROPER'IY

OF

TRlliYDRAZINIUMMONOAQUOTE1RA(PYRAZINE-2-CARBOXYLATO)NEODYMIUM(III) DINI1RATE, (N 2H 5h[ND(PC) 4 (H20)](N03l2

T. Premkumar, S. Govindarajan* and Nigam P. Ratha. Department of Chemistry,
Bharathiar University, Coimbatore 641046. aDepartment of Chemistry. Universityof Missouri-St Louis, MO 63121.
Trihydrazinum monoaquotetra (pyrazine-2-carboxylato) neodymium (III) dinitrate,(N2Hsb[Nd(pc) 4 (H 20)](N0 3 lz,where pc = pyrazine-2-carboxylate. crystallizes in the
monoclinic space group C2/c , with a = 10.7176(7). b = 21.7630(13). c =14.9608(9) A. {3 = 104.468(4) 0 and Z=4. The structure was solved by heavy atom
method and refined by Full-matrix least-squares method to an R value of 0.0272(A.
= 0.71073 Al for 4911 independent reflections . The crystal consists of discrete
N2H5+, Nd(pc) 4 (H 20) and N0 3 ions. The structure contain monomeric molecules.
in which the neodymium ion has nine coordination, formed by four oxygen atoms
from monodendate carboxylic groups of four pyrazinic acids (mean Nd-0=2.4180
A). four heteroring nitrogen atoms located next to the carboxylic groups (mean
Nd -N = 2.6744A) and one oxygen atom from water molecule (Nd-0 = 2.490 A). The
simultaneous TG-DTA of the compound shows a broad endotherm at 216°C
corresponding to the loss of a water molecule, indicating its coordination to themetal ion. A network of hydrogen bonds operating via the coordinated watermolecule, nitrate, carboxylate and hydrazinium ions maintain the stability of thecrystal.
Email: prem2468@yahoo.com

A4-59CRYSTAL
STRUCTIJRE
OF
w-[4-(4-ME'IHOXYPHENOXYCARBONYL)PHENOXYCARBON-YL] PENTYL 4-FERROCENYLBENZOATE

T. Takahashi, K. Uno, T. Hanasaki and N. Nakamura, Department of Applied
Chemistry, Faculty of Science and Engineering, Ritsumeikan University, 1-1-1 ,Nojihigashi, Kusatsu, Shiga 525-8577, Japan.
The structure of a monosubstituted ferrocene derivative, C 37 H 3 4 0 7 Fe, wasdetermined by the X-ray diffraction method. The single crystal of the title
compound was obtained from a solution with a mixed solvent of ethyl acetate andethanol (1:3) by the slow evaporation method. All measurements were made on a
Rigaku AFC-5R diffractometer with graphite monochromatized Cu-Ka radiation.
The crystals belong to monoclinic system, space group ?2 1 , a=8.860(3JA.
b=9 .955(4)A. e=36.092(3)A and {3=97.01(2) 0 • All calculations were performed using
the TEXSAN crystallographic software package. The structure was solved by direct
methods (MULTAN88) and expanded using the Fourier Technique. All nonhydrogen atoms were refined anisotropically and the hydrogen atoms wereintroduced at their theoretical positions and allowed to ride with the carbon atoms
to which they are attached. The final refinement was made by full-matrix leastsquares based on 6084 observed reflections (F2>-3.00a{F2)) . The refinement was
concluded with final reliability factors R(F2>-3.00a{F2))=0.039, wR(F2)=0.129 . The
molecular feature is a rod-like one and cyclopentadienyl rings exhibit an eclipsed
conformation rather than a staggered one. The unit cell of the crystal contained
two crystallographically unequivalent molecules A and B.
Email : rc005975 @se.ritsumei.ac.jp

A4-60

DIRECT OBSERVATION OF PHOTO-INDUCED PHENYLNITRENES BY X-RAY
CRYSTALLOGRAPHY

T.Takayamaa, M.Kawanob, H.Uekusaa, Y.Ohashia, and T.Sugawarac. aoepartmentof Chemistry and Materials Science, Tokyo Institute of Technology, Ookayama 212-1, Meguro-ku, Tokyo, Japan, bCREST(JST), and coepartment of Basic
Science,University ofTokyo, Komaba3-8-1, Meguro-ku , Tokyo, Japan.
Phenylnitrene is important as an intermediate of the chemical reaction ofphenylazide, that is an archetype for many photoaffinity labeling approaches and'photoresist' technologies. From the spectroscopic studies , it has been reported
that the powdered samples of phenylazide derivatives produced phenylnitrenes
upon photo-irradiation. However, crystal structure of phenylnitrens is notreported so far because of its high reactivity. In this study, the structure ofphenylnitrenes, generated in a single crystal by photo-irradiation at 80K, wasinvestigated by X-ray crystallography.
2-azidobiphenyl (1) was synthesized by diazotization of 2-aminobiphenyl andcrystallized from toluene. Single crystal of 1 was irradiated by ultra high-pressure
mercury lamp (A.> 420nm) at SOK, then X-ray diffraction data of the crystal wascollected on a SMART CCD diffractometer. On irradiation, the crystal turned fromcolorless to brown , and cell lengths were significantly changed. Successfully, thestructure of photo-induced 2-nitrenobiphenyl (2) in the crystal was revealed by Xray diffraction analysis . The occupancy of 2 was 21.8%. Existence of 2 was also
confirmed by cryogenic IR spectroscopy and theoretical calculation. Other
phenylnitrenes are now investigated by a similar method.
Email: ttakayam@chem.titech.ac.jp

A4-61CYCUC OXOCARBON DIANIONS AS HUBS IN TiiE SELF-ASSEMBLY OF
SUPRAMOLECULARSTRUCTURES

Chi-Keung Lam and Thomas C. W. Mak, Department of Chemistry, The Chinese
University of Hong Kong, Shatin, New Territories , Hong Kong SAR, P. R. China.
In the course of our systematic investigation on novel inclusion compounds ofurea/thiourea/selenourea with quaternary ammonium salts,lll we found that an
elusive species such as allophanate NH 2 CONHC0 2 - 121 or dihydrogen borate
BO(OHh- 13 1 can be generated in situ and stabilized in a hydrogen-bonded
urea/thiourea/selenourea-anion host framework . The non-benzenoid aromatic
dianions Cn0n 2 - (n = 3, deltate; n = 4, squarate; n = 5, croconate; n = 6 ,rhodizonate) are each a potentially effective divergent multi-site hydrogen-bondacceptor for supramolecular assembly. Following our initial studies on thesquarate ion,1 4 1 we have extended our investigation to the croconate and relatively
unstable rhodizonate species, and recent results will be presented. This work is
supported by Hong Kong Research Grants Council Earmarked Grant CUHK4206/99P.
[1]
[2]
[3]
[4]

T. C. W . Mak, Q. Li, in Advances in Molecular Structure and Research (Eds .:M. Hargittai, I. Hargittai). JAl Press. Stamford, Connecticut, 1998, Vol. 4, pp.
151-225.
T. C. W . Mak, W. H. Yip, Q . Li, J . Am . Chern. Soc. 1995, 117, 11995-11996.
Q. Li, F. Xue, T. C. W. Mak, Inorg. Chern. 1999, 38, 4142-4145.
C.-K. Lam, T . C. W. Mak, Zh. Strukt. Khim. 1999, 40, 883-891; Cryst. Engng.
2000, 3, 33-40, 225-226; Tetrahedron 2000, 56, 6657-6665.

Email: tcwmak@cuhk.edu.hk

A4-62NOVEL COORDINATION AND SUPRAMOLECULAR POLYMERIC NE1WORKS OFCADMIUM USING SELENOCYANA1E AS A BUILDING BLOCK

Tian-Huey Lua, Golam Mostafaa, Tapas Kr. Majib, Saugata Sain, Nirmalendu Ray
Chaudhurib. aoepartment of Physics, National Tsing Hua University, Hsinchu
300, Taiwan, R.O.C. and bOepartment of Inorganic chemistry, Indian association
for the cultivation of science, Kolkata-700032, India.
The molecular self assembly of coordination polymers and supramolecules is apromising route to novel molecular materials. These materials not only generate
new insights into structural diversity but also exhibit potential applications . The
versatility of an ambidentate selenocyanate ligand as an effective building block israre in the literature, which can provide much controlled synthesis due to hard(N) and soft (Se) combination. Controlled assembly of donor and acceptor building
blocks to generate an entirely supramolecular coordination architecture is ourultimate aim, using the potential bridging ability of SeCN with a cadmium metal
centre, which can permit a wide number of geometries and coordination numbers.
We wish to present the syntheses and structural diversity of four novel
selenocyanate bridged networks of cadmium,[Cd 2(ibn)(SeCN) 41n (1), [Cd 2(iprdien)(SeCN)4ln (2), [Cd2(medien) (SeCN) 4ln (3) and [Cd2(pyz) (SeCN) 4ln and (4)[ibn=l,2medien=bisdiamine-2-methyl propane ,iprdien=N 1- isopropyldiethyelentriamine,(2-aminethyl) methylamine and pyz=pyrazine). Complexes (1) and (2) are 10 and
20 coordination polymers respectively, with alternating arrays of octahedral andtetrahedral cadmium centres and each of them show 'symbiosis' following
Jorgenson principle. Complex (3) is a 10 coordination polymer forming a 20
supramolecular polymeric network by noncovalent interaction. Complex (4) is a
20 architecture of cadmium bridging simultaneously through SeCN and pyrazine
creating a square type molecular box.
Email: thlu@phys.nthu.edu. tw

A4-63
A GLANCE AT THE RECENT DEVEWPMENTS IN THE SUPRAMOLECULARCHEMISTRY

V. R. Pedireddi, Division of Organic Chemistry, National Chemical laboratory,
Pune 411008.
Supramolecular chemistry - chemistry beyond the molecule as defined by Lehn 1
has evolved as a multidisciplinary area extending its roots into various branchesof science; biology to computing areas.
The simplicity in the synthesis,
rationalistic approach in the design strategies, developments in thecharacterization techniques such as NMR and X-ray, and above all, theapplications of the materials thus synthesized to meet the needs of 21 st century
made the supramolecular chemistry as one of the frontier research area s of thiscentury. Although, it has started with the synthesis of crown ethers incorporating
guest molecules in the cavities, 2 the process indeed is well known in biology muchearlier in the form of molecular recognition between protein/DNA and small
molecules through non-covalent bonds such as hydrogen bonds. 3 This is theknowledge that has stimulated the design of variety of assemblies employing smallorganic molecules connected by noncovalent bonds, for example , 0-H- ··0, N-H-··0 ,N-H ··N, C-H- ··0 etc.4 In this process, noncovalents bonds of several types havebeen either explored or reinvestigated determining their properties
unambiguously. Although, the assemblies constructed by non-cova lent bonds areoften unstable, the rigidity of the metal-ligand linkages in the form of dative bondsin the coordination polymers added a new dimension to the supramolecularchemistry by facilitating the formation of variety of supramolecular architectureswith high degree of stability.5 The salient features of these assemblies (hydrogenbonded and metal-ligand structures) will be presented along with the results
evolved from our laboratory in the last few years.
(l)(a)Lehn , J. M. Supramolecular Chemistry; VCH : Weinheim, 1995. (b) Desiraju,
G. R. Crystal Engineering: The Design of Organic Solids; Elsevier: Amsterdam,
1989.
(2)(a)Lehn, J. M. Science, 1986, 225, 849.(b)Cram, D. J. Science, 1983,219, l.
(3) Saenger, W. Principles of Nucleic Acid Structures; Springer-Verlag: Berlin,
1984.
(4)(a) Desiraju, G. R. Angew. Chem. Int. Ed. Engl. 1995, 34, 2311. (b) Pedireddi,
V. R.; Chatterjee, S.; Ranganthan, A.; Rao, C. N. R. J. Am. Chem. Soc. 1997, 119,10867. (c) Ranganathan, A.; Pedireddi , V. R.; Rao, C. N. R. J. Am. Chern. Soc.
1999, 21 , 1752. (5)Yaghi,O.M. Acc.Chem. Res. 2001, 34, 319.
Email: pediredi@ems.ncl.res.in

A4-64

FORMATION OF SHEET 'IYPE S'IRUCTIJRE FROM CASHEW NET SHELL LIQUIDUSED AS A MONOMER FOR POLYESTER SYNTIIESIS

Vedavati. G. Puranika, Rahul D. Shingteb and Prakash P Wadgaonkarb, a:
Physical Chemistry Division., b : Polymer Chemistry Division, National Chemical
Laboratory, Pune- 411008, India.
A new bisphenol (a), has been synthesized from the cashewnet shell liquid (CNSL).

Its preparation and use for polycarbonate synthesis has been patented 1 . Crystalsof C 33 H 50 0 2 belong to the triclinic space group P-1, a= 6 .938 (1), b = 9.907(1), c =21.841(3) A, a = 87.982 (3) 0 , ~ = 83.377 (3) 0 , y = 84.644(3) 0 , V = 1483.9(6)A3 .
Data were collected on Bruker SMARr APEX CCD Single Crystal X-ray
Diffractometer using Mo-Ka radiation. The structure was solved and refined using
SHEU(I'L Present R = 0.079, for 1236 unique observed reflections. Crystal
structure shows a long alkyl chain (b) of 15 carbon atoms. The alkyl substituentsfrom adjacent H-bonded chain interdigitate and crystallize to form a sheet.
Between the polar groups, net work of 0-H ... 0 hydrogen bonds are seen a longwith C-H ... n interactions. The long non-polar C15

\
(b)
(a)

(c)

alkyl chain interacts with the chains from above and below to form sheets
through weak vander Waals forces (c).
Reference: 1US Patent No. 6255,439 (2001).
Email : vedavati@sil.ncl.res.in

A4-65
ABSOLUTE CONFIGURATION OF SPIRO ~-IACTAM: CRYSTAL STRUCTURE OF
N(4-METHOXYPHENYL)-3-(SPIRO
1,3 OXATIIIANE)-4-PHENYL-AZETIDINE-20NE

Vedavati. G. Puranika, D. Krishnaswamyb, B. M. Bhawa lb and A. R. A. S .
Deshmukhb, a: Physical Chemistry Division.,.b: Organic Chemistry Division,
National Chemical Laboratory, Pune- 411008 , India.
The spiro ~-lactam m. N (4-methoxyphenyl)-3-(spiro 1,3 oxathiane)-4-Phenylazetidine-2-one, was synthesised via ketene imine cycloaddition reaction(Staudinger Reaction). Deprotection of the oxathiolane group will give 3-oxo-13lactam, which is an important intermediate for the synthesis of various
biologically important compounds which show ~-lactamase inhibitor activity 1 .
They are also precursors for the 3-hydroxy-4-aryl-~- lactams of which 4-phenyl
isomer:H=N ~O M e~-

K etene
Imine

___.

e~~~:rq

II

is used as a synthon for the Taxol side chain2 . Crystals of C 26 H29 N0 3 S belong toorthorhombic, space group P2 12 12 1 , a= 6 .442(4), b = 18.091(1), c = 19.393(1) A
V= 2260.1(3) A3 . Data were collected on Bruker SMARr APEX CCD Single Crystal
X-ray Diffractometer using Mo-Ka radiation. The structure was solved and refinedusing SHELXTL Least squares refinement of scale, positional and anisotropic
thermal parameters converged toR= 0.042, Rw = 0.094 for 5355 unique observedreflections. Molecular structure shows that the approach of imine is from the
opposite side of gem- dimethylmethylene bridge.
References: 1 .Buynak, J. D .. Doppalapudi, V. R., Frotan, M., Kumar, R. andChambers, A. Tetrahedron, 2000, 56, 5709 2 . Srirajan, V., Deshmukh, A. R.A. S .
and Bhawal, B. M. B. Tetrahedron, 1996, 52 , 5585
Email : vedavati@sil.ncl.res.in

A4-66

S1RUCTURAL AND CHEMICAL PROPERTIES OF NITRIDO ANDCARBONYL CLUSTERS OF RUTIIENIUMNITRENE

Wing-Tak Wong, Department of Chemistry, The University of Hong Kong ,Pokfulam Road , Hong Kong, P.R. China.
Nitrido and nitrene clusters are members of a potentially vast class of mixed
transition metal-main group compounds.
Such molecules are currently of
structural and chemical interest since they offer opportunities to evaluate thevalidity of current models of bonding for mixed polynuclear systems and to
improve on the degradative instability of homonuclear metal compounds. Metal
surface-bound nitrido and nitrene species are believed to be an integral part in a
number of heterogeneously catalyzed chemical processes such as nitrogen oxide
reduction, the Haber process and hydrazine decomposition. In light of the metalcluster-metal surface analogy, the low-valent nitrido and nitrene are particularlyinteresting. In several surface reactions involving NO or N2 , adsorbed nitrogenatoms are known to be key intermediates. To enhance our understanding in thesesystems, we have developed some synthetic routes to tetranuclear ruthenium andruthenium-cobalt carbonyl clusters containing nitrido or nitrene ligands . Theirstructural and chemical properties have been investigated. These clusters display
novel metal-nitrene core structures and their electrochemical properties together
with the 15-N NMR spectroscopic studies have been investigated. The magnetic
nuclear deshielding of nitrene N-atoms increases with the nuclearity and electronaccepting ability of the organic substituent bonded, while the chemical shift of aninterstitial nitride increases with compression of the interstitial nitrogen in a
metal cluster.
E-mail : wtwong@hkucc.hku .hk

A4-67

CRYSTAL STRUCTIJRE OF TilE NOVEL CU ( II ) POLYNUCLEAR NET-STILECOMPLEX OF N, N-BIS (BENZIMIDAZOL-2-YLMETHYL) AMINE

Xiao-Lan Liu Ru Zhao and Fang-Ming Miao College of Chemistry and Life Science ,Tianjin Normal University, Tianjin 3 00074, P.R.China
A novel Cu(II) polynuclear net-style complex of N, N-bis(benzimidazol-2ylmethyl)amine was synthesized and its crystal structure was determined by Xray
diffraction
method.
The
crystallographic
data
is
as
follows:
C4 zH 4 oN 1z0 17 Cl 4 Cu 2 , mr=1253.74, monoclinic system, space group Cc,
a=2.771(4). b=0.9432(ll). c=2.501(3) nm, ~=120 . 17(5) 0 , V=5.652(1 3) nm3,
Dc=l.473 Mgjm3, Z=4, F (000)=2552 , j.!=l.017 mm-1, R=0.0661, wR=0 .1462 ,8=0.971. The crystal structure shows that one stoichemistry molecule composedof two Cu(II) ions, two N, N-bis (benzimidazol-2-ylmethyl) amine, one 4 , 4bipyridyl as bridge, one water and four Cl0 4 - . A lot of stoichemistry molecules arelinked by Cl0 4 - to form one layer of net-style structure (see figure 1).

Figure 1 One layer of net -style structure of the complex of C4 2 H 4 oN 12 0 17 Cl 4 Cu 2
Email : miaofm@public.tpt.tj .cn

A4-68S1RUCTURAL STUDIES OF NEW DIORGANOTIN DITillOCARBAMATES

Y. Farinaa , A.H. Othmana, I. Babaa, S.W. Ngb and H.-K. Func, aschool ofChemical Sciences & Food Technology, Faculty of Science & Technology,
Universiti Kebangsaan Malaysia, 43600 Bangi,
bJnstitute of Postgraduate
Studies , Universiti Malaya, 50603 Kuala Lumpur, ex-ray Crystallography Unit,
Universiti Sains Malaysia, 11 800 Penang.
Dithiocarbamates and organotins have been cited in the literature as compounds
that can show biological activity. Some dithiocarbamates such as imuthiol(sodium diethydithiocarbamate) has been utilised in the pharmaceutical industry
while the organotins have been investigated for its anti-tumour activity. The neworganotin(IV) dithiocarbamates derived from various secondary amines weresynth esised using a method where the ligands were generated in situ and reacted
directly with the diorganotin(IV) moieties. Two crystals I and II were derived fromthe reaction involving 2-(2-hydroxy-ethylamino)-ethanol, while that with 2methylamino-ethanol and di-iso-propyl-amine afforded III and IV respectively.
I
II

..,
-~
:"' ~ - #

--

-

III

IV

The crystal structures of I, II, III and IV showed that the tin atom formed a six coordinate cis bis-chelated complex. The dithiocarbamate ligands chelated
anisobidentically with a distinct short and long Sn-S bond distances in I and IV,
while II and III demonstrated both anisobidentate and isobidentate chelations.
The angle subtended at the tin atom by the two alkly groups is bigger than that by
the two aryl groups due to steric requirements . The same trend was reported by
Lindley and Carr (1 974). The geom etry around the tin centre was not affected by
the presence of hydroxy groups, which gave rise to intermolecular andintra molecular hydrogen bonding in the crystal lattice.
Lindley, P .F., a nd Carr, P .. J. Cryst. Mol. Struct., 1974, 4 : 173-185.
Email: farina@pkrisc.cc.ukm .myA4-69
THE NOVEL LINEAR NONANICKEL METAL S'IRING [Nig(ug-PEPTEA)4(X)(Y) ]COMPLEXES X=Y=SCN- AND X=CF3So 3-,Y=CH30-

Yih-Lih Jang. Gene-Hsiang Lee, Shie-Ming Peng*. Department of Chemistry
National Taiwan University.
The synthesis, structure and properties of [Ni9 {peptea} 4 {X)(Y)]. X=Y=Cl-, X=Y=SCNand X=CF3 S03 -, Y=CH 3 0 -,{pepteaH 4 = pentapyridyltetraamine} metal string
complexes are reported. The nonanickel unit is essentially in a linear arrangement
and is helically wrapped by four all-syn type peptea4 - ligands. There are two axial
ligands { X and Y} attached at terminal nickel ions. According to the structural,
analysis the complex exhibits D 4 symmetry and there are four sets of Ni-Ni
distance, which are 2.364{2}, 2.283{2}, 2 .243{2}, 2.227{2} for X=Y=SCN- from outer
to inner, respectively. For these complexes , the average bond distance of Niinner-N
are short, consistent with a square planar, low spin arrangement of nickel{II} ions.
The termianl Nin ions ,Ni{l} and Ni{9}, are in a square-pyramidal form with long
Ni-N distance and high-spin state ~ A temperature-dependent magnetic study ofthese complexes, X=Y=Cl- , X=Y=SCN- and X=CF3 S0 3 -, Y=CH3 0 -, indicate that
there is a weak antiferromagnetic interaction between the two terminal high-spinnickel{II} ions with J = -2.lcm-1, -0.2 cm-1 and -0.9 cm-1, respectively. This
interaction is smaller than those of similar trinuclear {J= -99 cm-1}, pentanuclear{J= -8.3 cm- 1} and heptanuclear {J= -3.8 cm-1} complexes.

X

Email: jangyl.tw@yahoo.com.twyA4-70CRYSTAL STRUCTIJRE OF CHOLESTERYL 2,4-DICHLOROBENZOATEYoung Ja Park, Department of Chemistry, Soak Myung Women's University,
Seoul, KOREA 140-742.
Crystal of 2,4-dichlorobenzoate(C 3 4 H 48 0 2 Cl2 ), a cholesterol derivative, areorthorhombic, space group P2 12 12 1 , Z=4, a=9 .283(2), b=l3.462(3}, c=24.706(4)A,
Dc=l.20 g/cm3 . The intensity data were collected on a Nonius CAD-4
diffractometer with a graphite-monochromatized Mo-Ka radiation to a maximum
28 value of 52°.
The structure is solved by direct methods and refined by Fourier and full matrix
least-squares methods. The present R factor is 0.099 for 1542 observedreflections.
Compared with other cholesterol derivatives, the cholesteryl ring and tail region of
the molecule are normal. The structure of cholesteryl 2,4-dichlorobenzoate
molecules, have their tetracyclic systems almost · parallel to each other. The
molecular long axes are parallel to the c-axis and these molecules stack along 2 1
screw axes. Cholesteryl 2,4-dichlorobenzoate belongs to the layer type crystal
structure as in most cholesteryl esters and cholesteryl carbonates.
Email : yjpark@sookmyung.ac .kr

A4-71S1RUCTURE ANALYSIS OF UNSTABlE SPECIES PRODUCED BY PHOTO
IRRADIATION

Yuji Ohashi, Department of Chemistry and Materials Science , Tokyo Institute ofTechnology, 0 -okayama, Meguro-ku, Tokyo 152-8551 , Japan.
Many organic reactions proceed by multi-step processes in which intermediate
molecular species are involved in the conversion from one molecule to another.
Such intermediate molecules, in general, are so unstable at room temperaturethat the structure analysis has been considered to be very difficult. However. theunstable species produced by photo irradiation may be trapped in the crystalline
lattice at low temperatures and the structures can be analyzed by X-ray
technique. Recently we analyzed the structures of a triplet carbene and a nitrene
produced in crystalline lattice by X-rays when the reactant crystal was irradiatedwith UV or visible light at 80 K. Another example is the photo-excited structureof the platinum complex, [Bu 4 N] 4 [Pt2 H 2 (pop) 4 ] (pop = [P 2 0 5 H 2 ] 2 -). Two Pt atoms
are linked by four pop ligands in the anion. The unit-cell volume decreased when
the crystal was irradiated with visible light and returned to the original cell when
the light was off. The three-dimensional intensity data were collected with thelight on and off at low temperatures. The significant difference in molecular
structure was observed between the structures at light-on and -off states; the PtPt distance significantly decreased at the light-on state. The shortening of the PtPt distance well explains the excited state of the Pt-Pt orbital of the anion
assumed so far .
Email: yohashi@cms.titech.ac.jp

A5 : Cr yst all og rap hy in ma ter ial s
sci enc e\•.AS- 1STRUCTURE OF TIIE MORPHOTROPIC PHASE BOUNDARY (MPB) PHASE IN (1x) [Pb (Mg 1 ; 3 Nb 2 ;3l0 3 ]-xPbTi0 3 (PMN-P11 CERAMICS

Akhilesh Kumar Singh, S.K.Mishra and Dhananj ai Pandey, School of Materials
Science and Technology, Institute of Tech nology, Banaras Hindu University.
Varanasi-221005, India
PMN-PT ceramics possess excellent electromechanical properties useful for
piezoelectric transducer and actuator applications . The phase diagram of thissystem exhibits an MPB which separates tetragonal (T) and rhombohedral (R)phase fields similar to that in the well known Pb (ZrxTi 1_x)0 3 (PZT) system. The T
and R phases are believed to co-exist in the MPB region. Different workers havereported different compositional widths of the coexistence region depen ding upon
synthesis route adopted [Kelly et al. J .Am .Ceram.Soc. 80, 957, 1997, Shrout et al.
Ferroelectrics Lett. 12, 63 1990].
In this work we have used a new method of synthesis and shown that the width ofthe coexistence region is about 6x:o=0.05 which is an order of magnitude smaller
than that reported by Kelly et al. Further by using Rietveld refinement of x-ray
powder diffraction data. we have shown that the structure of PMN-PT in the MPB
region is monoclinic with space group Pm and not the mixture ofT and R phases.
hitherto believed. The lattice p a rameters of the monoclinic cell (x=0.34) are foundto be aM =4 .03A, bM=4 .00A. cM=4.01A and ~=89.86 degrees. This structure isdifferent from the monoclinic structure with space group Cm reported recently for
PZT.
Email : dpandey@banaras .ernet.in

A5-2

MICROTOPOGRAPIUC STUDY OF DOPED CRYSTALS OF LEAD IODIDE

Alka Garg Jain a and G.C.Trigunayatb. aoargi College,Siri Fort Road ,New Delhi. 110049. b Department of Physics &Astrophysics,Delhi University,Delhi - 110007.
Both undoped and doped crystals of lead iodide have been grown by the Vapour
technique. Growth features on the basal (000 !)surface of the undoped and doped
crystals were studied by optical and scanning electron microscopy. The mostfrequently observed growth feature has been the existence unevenly spaced
hexagonal/trigonal parallel growth steps. The steps presumably arise from layer bylayer growth mechanism as confirmed by calculation of Jackson's interface
roughning factor.The micrographs of the doped crystals display the familiar
phenomenon of bunching of growth steps to a smaller or larger degree.
The"bunched" step is built up , because the individual small steps slow down as they
move across the crystal surface, thus allowing the succeeding layers to catch up
with front layers . This slowing down is caused by the impurities on the surface.
When doped crystals were left over-night in the fumance ,they developed la rge
number of thermal hexagonal etch pits formed by the evapora tion of the material on
the surface in a manner reverse to that of crystal growth .They presumably form at
impurity - contained locations or at impurity aggregates
Email : dee nee@bol.net.in

A5-3

RELAXOR FERROELEC'IRIC PHASE TRANSffiON
S'IRUCTIJRAL AND DIELEC'IRIC STIJDIESIN

Pb 0 .50Ca 0 . 50Ti0 3 :Arnreesh Chandra, Rajeev Ranjan and Dhananjai Pandey, School of Materials
Science and Technology, Institute of Technology, Banaras Hindu University,
Varanasi- 221005, India
Studies on Pb 1 _xCaxTi0 3 (PCT) have attracted enormous attention . While the effectof low Ca2 + content (x<0.40) on the structure and phase transition behaviour of
PCT is well understood, there are several conflicting reports for X>0.40 andespecially for the composition x=0.50. Sawaguchi and Charters (J . Am. Ceram.
Soc., 42, 158, 1959) reported that the temperature variation of dielectric constant(EI(T)) in PCT50 ceramics prepared by conventional solid state route exhibit two
peaks while Ganesh et ai (J. Am. Ceram. Soc., 80, 653 , 1997) have observed onlya single peak. Ranjan et ai (Appl. Phys. Lett., 70, 3221 , 1997) have reported
relaxor ferroelectric transition in PCT50 samples prepared by a semiwet route.
Rietveld analysis of powder x-ray diffraction data on PCT50 samples obtained byconventional solid state route reveals the presence of two phases with P4mm andPbnm space groups due to limitations of the solid state route. EI(T) measurements
also reveal two peaks in E*(T) corresponding to a ferroelectric and a relaxor
ferroelectric phase. Following Ranjan et al, we propose that the orthorhombic
phase is the relaxor ferroelectric phase and it has got tilted octahedral structure
similar to CaTi0 3 . We have also studied the effect of sintering temperature on therelative proportions of these two phases.
Email : dpandey@banaras.ernet.in

A5-4

INVESTIGATION ON SYNTHESIS ,CHARAC'IERISATION AND EFFECT OF Ag
DOPING ON THE TRANSmON 'IEMPERATURE AND CRITICAL CURRENT
DENSTIY OF Hg1-xPbxBa2Ca2Cu308+B (0. 1::; x ::; 0 .5) HTSC TAPES

Anjana Asthana and O.N.Srivastava, Dept. of physics, B.H.U Varanasi, India
Pb-doped Hg1223 HTSC tapes have been synthesized by annealing the precursor
tape (fablicated by doctor blade tape casting technique) in the environment ofHg(Pb) vapour in an evacuated sealed quartz tube at 87ooc for 8 h. The HTSC
tapes with x ranging between 0.1 and 0.5 exhibit high temperature
superconductivity at temperatures falling in the range of 110-119 K. The tapesample with optimum doping of Pb 0 .35 has a highest Tc of ~ll9K and 5 . 1x103
A/ cm 2 . Gross structural charactelisation of as-synthesised Hg(Pb) HTSC tapesample shows the dominant presence of Hg(Pb)-1223 tetragonal phase. Assynthesised Hg(Pb)Ba 2 Ca2 Cu 3 0s+o HTSC observed under transmission electron
microscope also confirmed the dominant presence of Hg(Pb) 1223 tetragonal,
phase.With the slight addition of Ag into optimally Pb doped Hg- 1223 tapesample, Tc has been found to increase slightly but there is significant
enhancement of Jc up to a optimum concentration of Ag. The highest Tc of ~ 123
K and highest J c of ~2.5 x10 4 A/cm 2 is obtained for the tape sample having Ag
concentration of 0.2 i.e ., (Ag 0 .2 ) being an order of magnitude higher than the J c ofAg free optimally Pb-doped Hg-1223 tape samples . The surface microstructuralcharacterisation of the optimally Pb doped HTSC tape sample show quite uniform
platelet like grain stucture.
Email : asthanaa@rediffmail.com

A5-5

INFLUENCE OF TilE PARAMETERS T AND icum(T)S'IRUCTURAL CHARACTERISTICS OF POLYMERS

ON

TilE

CRYSTAL

Anjana Jain and Kalyani Vijayan, Materials Science Division, National Aerospace
Laboratories, Bangalore 560 017, India.
Thermally induced changes in th e crystal structural characteristics are often
associated with lattice expansion, contraction, phase transformations etc. These
effects are generally identified by th e parameter, temperature(T). at which they a refound to occur. Detailed investigations on the crystal structural characteristics ofthermally aged polymers have shown that in addition to the parameter T, theduration of cumulative exposure to a constant temperature, tcum(T). also
introduces changes in the crystal structural characteristics, very similar to the
influence ofT. The combined role of the parameters T and tcum(T) has led to theidentification of a (T, tcum(T)) effect on the crystal structural characteristics viz.,changes introduced at temperature T 2 can recur at temperature T 1 (< T 2 ) also, if
th e exposure to the latter is long enough. Details of the observations based on the28, intensity, half width and azimuthal spread of reflections from various
thermally aged polymers will be presented in this paper.
Email: janjana@css.cmmacs.ernet.in

A5-6

PRELIMENARY X - RAY STIJDIES OF THE MESOGEN TRANS, TRANS - 4 - N PROPYLBICYCWHE~4'-CARBONITRI1E AS A FUNCTION OF 1EMPERATURE

Kanishka Bhowmick and Anuradha Mukhopadhyay, Dept of Physics, Jadavpur
Univeristy, Kolkata- 700032, INDIA.
The compound trans, trans - 4 - n - propylbicyclohexyl - 4' - carbonitrite(abbreviated to CCH 3 ) is a member of the homologous mesogenic series of
cyanocyclohexyl cyclohexanes having the structural formulaCnH2n+
~
_ __
~--

~

CN,

(n=3 for CCH3 ). The Compound CCH 3 (molecular formula C 1sH2 7 N) exhibits thefollowing phase transitions
58°C

Solid

80°C
IIJWemat~

Isotropic_.. :( 8°

A4°

_AR0

57°

Smectic1 ~ Smectic2~ Smectic~ Smectic~ Nematic -E-----Though much work has been done on the compound and other members of theseries including its crystal structure determination [1] in the solid phase, not all
the smectic phases have been identified . Also the intermolecular separation 'd 1'
and apparent molecular length/ layer thickness 'd 2' and their variation withtemperature over the various mesophases have been studied with a view todetermining d 1 and d 2. X-ray photographs have been taken and d 1 , d2 calculated
from the radii of the rings obtained on the photographic plates at various
temperatures. Correlation is sought between the solid state cell parameters [1]and the parameters d 1 and d 2 in the liquid crystalline phase.
References :[1] W. Hasse and H.Paulus. Mol. Cryst. 100, 111- 126 (1983)

Email : ann@juphys.emet.in

A5-7
CHARA.C1ERIZATION OF STABILIZEDCOOPRECIPITATION METHODYTRRIA-ZIRCONJAPRODUCED

BY

Bambanga, Ruslana, Sri Soejatia, R. Charnayb, aRessearch Center for Materials
Science, Department of Physics , University of Indonesia, Kampus UI, Depok
Jakarta 16424, Indonesia, b Ecole Centrale de Lyon, MMP laboratory, France
The Coo precipitation method was used to produce stabilized ytrya-Zyrconia
ceramic. The samples were synthesized from Zr0Cl.8H 2 0 and Y-acetate, withpurity better than 99%, available commercially from E- Merck and Aldrichrespectively. The content of Ytrya was 7%, 9%, and 11% mole . The produced
precipitate was calcined at 500 °C. Two kinds of particle size i.e. 0.5 1-!ffi and 5 11m
obtained from milling were pelletized under 5 ton pressure and then sintered attemperature: 1100 °C, 1200 °C, 1300 °C, and 1400 °C for 2 hours . Structural
analysis shows that the crystal structure is monoclinic. Particle size and sintering
temperature influenced greatly on electrical properties as well as its
microstructure, but it did not influence to crystal phase. Samples with size 0.5
11m have densification = (93 -95) %, porosity < 2%, hardness Vickers = (13- 15)
Gpa, coefficients of thermal expansion= (16- 20) x 10 -6 ;oc. Samples with size 5
11m have densification = (83 -84) %' porosity= ( 14 -17) %, hardness Vickers = ( 10-12) Gpa, electrical conductivity at 100 °C < 0.01 (Ohm em) -1 , and coef. ofthermal expansion= (15- 18) x 10-6 ;oc.
Email : bambang@fisika.ui.ac.id , amirah@indosat.net.id

A5-8
HARDNESS, FRACTURE MECHANICS AND CRACK PROPAGATION STUDIES ON
MELT GROWN DOPED KMgF3 CRYSTALS.

Banwari Lal, K.K.Bamzai & P.N.Kotru. CGMR-Lab., Department of Physics,
University of Jammu, Jammu- 180 006 (India).
Fresh (100) cleavages of melt grown doped KMgF3 crystals, grown by Czochralski
pulling technique with 5% doping of NiF2 , were subjected to indentation induced
hardness testing studies using Vicker's micro hardness tester mhp - 100 attached
to Neophot-2 of Carl Zeiss, Germany. The Vicker's micro hardness value (Hvlranges from (4 .65-2. 72) x 102 Kg/ mm 2 in the load range of 10-100 g respectively.
The variation of micro hardness with load is best explained by Hays and Kendall's
law and the value of Newtonian resistance pressure (W) offered by the sample isfound to be 19.59 x 10-3 Kg. The fracture toughness (Kcl determines how muchfracture stress is applied under u niform loading and its value is found to vary
between (0 .0720-0.0602) x10-3 Kg/J..Lm3/ 2 in the load range 20-100 g respectively.
The brittleness index (Bj) and yield strength (o'yl are reported to lie in the range(5 .98-4 .52) x J..Lm- 1/ 2 and (143.52-90 .78). From the ratio of crack length to half
diagonal length (c/a), it is indicated that these crystals exhibit only median typesof cracks and brittleness of 1- 4 standard.
Email : pn_kotru@ yahoo.com

A5-9

THE RElATIONSHIP BE1WEEN STRUCTURE AND NONLINEAR PROPERTIES OF
Bi 2 B 8 0 15 SINGLE CRYSTALS*

Bing Teng, Wentao Yu, Jiya ng Wang, Xiaobo Hu, Shengming Dong State Key La b
of Crystal Materia ls, Shandong University, Ji 'n a n 250100, Peo ple's Republic of
China
The borate family of crystals plays a very important role in the field of n o nlin ea r
optics . A large number of borate crystals, including ~ - B a B 2 0 4 (BBO) , LiB 3 0 5(LBO), RECa 4 (B0 3bO(RECOB, RE= Y, Gd, Nd, Sm) and Bi8 30 6(BIBO), have beenstudied or some are useful NLO crystals.
Bi2Bs0 15 melts congruently at 715 °C. It has two modifications, i. e. a h igh
temperature phase (a.) and a low temperature phase (~) . The structure of ~ - form
Bi2Bs 0 15 was determined for the first time by BRUKER-P4 four -circle
diffractometer. It is monoclinic with a noncentrosymmetric structure, where[B305] rings and [Bi0 6] octahedra in which the bismuth cation with a lone-pairelectron are located. Similar to BBO, the NLO-active clusters in a Bi2B8 0 15
crystals are [B 30 6] rings . According to the anionic group theory. the a nionicgroups [B30 6] with the distortions of the idealized structures h ave the microscopic
contributions to the second-order susceptibility of the group. In addition, [Bi06l
octahedra with a lone-pair electron in Bi do contributes to the NLO effect. The
above structure factors show that Bi 2B 8 0 15 is a potential NLO crystal.

* This work is supported by a Grant for the State Key Program of China ..
Email : bteng@icm.sdu.edu .cn

A5-10S1RUC1URALINVESTIGATIONSSUPERCONDUCTING SYS'IEM

OF

La-2125

MIXED

OXIDE

S. Rayaprola, Kl:ushna Mavania, D. S. Ranaa, C. M. Thakera, R.S. Thampia, D.G.
Kuberkara, S .K. Malikb and R.G. Kulkarnia aDepartment of Physics, Saurashtra
University, Rajkot 360 005, India, and hSolid State Physics Division, T.I.F.R,
Mumbai 400 005. India.
Crystallographic studies on the (La2-xNdxlCayBa2Cu 4 +yOz [y = 2x; 0.0<X<0.5]
samples are carried out using neutron diffraction technique. The analysis of theneutron diffraction patterns for the series of samples with 0.0 < x < 0.5 was doneusing Rietveld fitting program. The La 2Ba2Cu 4 0 z (La-224, x = 0.0) exhibits
tetragonal phase and is a non-superconductor which becomes superconducting
on addition of a 'CaCu0 2' rock salt like layer with maximum Tc of 78K. It is
important to note the significant role played by Ca-doping in improvising thesuperconducting properties. Analysis of the structural data reveals that, as Caconcentration increases , the unit cell volume decreases while Tc increases with amaximum value of Tc - 78K for x = 0.5. The detailed crystal structure for
LaNdCaBCO series of samples has been studied in the light of changes in bondlengths and bond angles with increase in Ca-concentration and it's role in'turning on' the superconductivity.
Email: dgk@rajkotonline.com. dgk@adl.vsnl.net.in

A5-llRECENT DEVEWPMENTS IN STRUCTURAL AND PHASE 1RANSIDON STUDIESON Pb(ZrxTil_J03 CERAMICS

RaginP, Rajeev Ranjana, S . K. Mishraa. B. Kennedyb and Dhananjai Pandeya,aschool of Materials Science and Technology, Institute of Technology, Banaras
Hindu University, Varanasi-221005, India andbSchool of Chemistry, The
University of Sydney, NSW 2006, Australia.
We report the results of structural, dielectric and piezoelectric investigations onhighly homogeneous Pb(Ti 1_xZrxl0 3 (PZf) ceramics prepared by a novel semi-wet
route. Careful analysis of the x-ray diffraction profiles have revealed that thestructure of PZf on the Zr rich side (~0.530) of the morphotropic phaseboundary (MPB) is not rhombohedral, as hitherto believed for decades, but is
monoclinic. Results of the Rietveld analysis of the room temperature powder XRD
data are presented for 0.515~0.530. We show that the co-existence ofmonoclinic (FMHI) and tetragonal (FTl phases for x=0.520 and 0 .525 is due to afirst order phase transition. Piezoelectric and dielectric measurements as afunction of temperature for 0.515~<0 . 550 have revealed two anomalies
corresponding toFT to FMHT and FMHT to FMLTtransitions discovered by Noheda etal [Phys . Rev. B 61(2000) 8687) and Ragini et al [Phys. Rev. B 64 (2001) 054101).
respectively. Neutron diffraction data is presented to show that the FMHT to FMLTtransition is an antiferrodistortive cell doubling transition associated with phonon
instability at the R-point of the cubic Brillouin zone . We show that the spacegroup of the FMLT phase is Pc which is different from the Cm space groupproposed by Noheda et al for the FMHT phase .
Email : dpandey@banaras.emet.in

A5-12
SMALL ANGLE X-RAY SCATTERING OF MESOPOROUS Zr0 2 XEROGEL

Zhi Hong u a, Dong Wua, Yu Han Suna, Zhao Hui b, Jun Wangb, Bao Zhong
Dongb. astate Key Laboratory of Coal Conversion, Institute of Coal Che mis try,
Chinese Academy of Sciences , P. 0 . Box 165, Taiyuan 030001, P. R. China.
bSynchrotron Ra diation La boratory, Institute of High Energy Physics , Chines e
Academy of Sciences , P. 0. Box 918 , Beijing 100039, P. R. China .
Zr0 2 xerogel wa s prepared using sol-gel process from the mixture ofZr(OC3H 7 l4;3H20:30(C2H 4 0Hb;0 . 1AEOg:65C2H50H; then the mixture wa stransferred into a stainless autoclave lined with Teflon for the thermal treatment
at 23o·c for 72h; at last the resulted precipitation wa s filtered , washed and driedat so·c for overnight. So produced sample possessed mesoporous structure as N2
adsorption-desorption n;J.easurement has indicated . Small angle X-ray scattering(SAXS) using synchrotron radiation as X-ray source with a long-slit collima tionsystem at Beijing Synchrotron Radiation Laboratory wa s used to study the
structure of the mesoporous Zr0 2 xerogel. It is seen that the Debye plot of J obs(qj ·2 /3 versus q 2 deduced from the original m easured scattering data is not linea r but
presents a downward concave curve . It is obvious that the scattering does notobey Debye's theory but shows a positive deviation from Debye's theory,suggesting that the sample is not an ideal two-phase system and there exists
micro-inhomogeneity of electron density within the solid phase of Zr0 2 xerogel.
This is probably due to the crystallization under 230"C is not b eing full and theamorphous matter existing in the skeleton. i.e. the sample is in semicrystalline
state as confirmed by XRD pattern. Here, we extend Debye's equation from ideal
two-phase system to non-ideal two-phase system that shows a positive deviationfrom Debye's theory; and then we correct the deviation from Debye's theory andgive information on the microstructure of the m esoporous Zr02 xerogel.
Email: wudong@public .ty.sx.cn

A5-13
STRUCTIJRE OF (n=4) FERROELECTRIC AURIVILLIUS PHASES: AB4~0 1 s (A=Ba,Sr and Ph)

G. Nalini and T . N. Guru Row, Solid State and Structural Chemistry Unit, Indian
Institute of Science, Bangalore 560012, India.
The room temperature structure of three ferroelectric compounds belonging to
the Aurivillius family (n=4). ABi4Ti40 15(A=Ba,Sr and Pb) have been analyzed
using high resolution powder X-ray diffraction methods. BaBi4Ti4015 crystallizes
in 14/mmm space group with a =3.8566 (1) and c=4 1.8457(14)A. The structure h as
been refined by Rietveld method to Rp=5.40%, Rwp=7.16% and Rt 1• hk1J=l0.49%.
On the other hand SrBi4Ti 4 0 15 and PbBi 4Ti 4 0 15 crystallize in (nearlyisomorphous) space group A2 1 am with a=5.4510(4). b=5 .4410(4) and
c=41. 0233 (1 3)A and a =5.42 55 (1). b=5.4440(1) and c=41.4023(13)A respectively.
The starting model for SrBi4Ti4015 and PbBi4Ti401 5 was derived from abinitio
methods u sing the package EXPO together with the information available in the!COD database. The model was fu rther refined to Rp=5.63%, Rwp=7 .36% Ro.
hktl=8 .90% and Rp=7 .25% Rwp=l0.59% and Ro. hk1J=l0.25% respectively. It isseen that the A cations Ba and Sr are disordered over the Bi sites. However, thePb analogue has a well-defined site at x=0.281 6(7). y=0 .2586(6) z =0.2185(1) for
Pb which clearly indicates that Pb is the 2 + oxidation state. Also the B-0 bonds inthe perovskite layers are highly distorted forming the zigzag chains along the 'c'axis . There is a general displacement of the Bi atoms along the a axis w hich is
responsible for the ferroelectricity in these compounds .
Email : nalini@sscu.iisc.ernet.in

A5-14FORBIDDEN REFLECTIONSABSORPTION EDGEOFHEMATITE(F~O:ll

NEAR

1HE

Fe

K-

Hidetaka Sawai, Ayako Watanabe, Yoshiyuki Ninomiya, Jun Kokubun and
Kohtaro Ishida Department of Physics, Faculty of Science and Technology, Tokyo
University of Science, Noda, Chiba 278-8510, Japan.
In order to investigate anisotropy of electronic and magnetic scattering fromhematite, alpha-Fe 2 0 3 , we measured the forbidden reflections near the iron Kabsorption edge using synchrotron radiation. At room temperature hematite hasan antiferromagnetic structure. The spins, however, are slightly canted, and it has
small magnetic moment perpendicular to [001]. We mounted a natural hematite
crystal with a (001) surface on a four-circle diffractometer. Energy spectra andazimuthal angle dependence of the (003) and (009) reflections were measured.
The (003) and (009) reflections have similar energy spectra, which show only one
r~sonant peak in the pre-edge region and a continuous non-resona nt tail below
the edge. Finkelstein et al. [1] attributed the peak to the electronic quadrupoletransitions . We measured the azimuthal dependence of the integrated intensities
at the peak position and the non-resonant tail. The azimuthal dependence of the(003) reflection measured for non-resonant tail shows twofold pattern. The site
symmetry of iron atoms in hematite is 3, therefore this profile should be caused
by non-resonant magnetic scattering. The azimuthal dependence of the (003)
reflection measured at the peak position showed threefold pattern. On the other
hand, the profile of the (009) reflection at the peak position showed threefold likepattern, but not a complete threefold pattern. We suppose that the resonant peakconsists of two components, electric and magnetic scattering, and they intricatelyinterplay.
[1) K. D. Finkelstein, Qun Shen and S . Shastri: Phys. Rev. Lett. 69 (1992) 1612.
Email : crystal@ph.noda.sut.ac.jp

A5-15X-RAY STIJDY ON THE EFFECT OF HEAT TREATMENT ON THE GROWTII MODE
IN ZnSe HETEROEPITAXY ON Te-TERMINATED GaAs (001) SURFACES

Hiroshi Chiba, Tomohiko Tagawa, Takaaki Isikawa, Takumi Matumoto, Hiroyuki
katoh,and Kohtaro Ishida. Department of Physics . Faculty of Science a nd
Technology, Tokyo University of Science, Noda, Chiba 278-8510, Japan.
The II-Vl/III-V heteroepitaxiallayers have been applied to the fabrication of wideband-gap optoelectronic devices. For heteroepitaxy of ZnSe on GaAs, the epitaxial
growth is relatively easy, since the lattice space mismatch between the two
crystals is small, 0.27% at RT. However, a ZnSe epitaxial layer grown on a GaAs
substrate contains many lattice defects which affect performance and reliability ofa device. The formation of defects in epitaxial layers strongly depends on theinitial pre-growth treatments of substrate surfaces prior to epitaxy, whichconsequently influences the growth mode. Therefore, there have been a great
number of studies on the effects of pre-growth treatments on the growth modeand defect generation.
The effect of thermal annealing of the Te-terminated GaAs (001) surface on theinterfacial structure of ZnSe / GaAs was studied by combining X-ray reflectivity
and diffraction measurements. Comparing the results obtained by the two
methods, we conclude that the growth of ZnSe epitaxial layers has changed froma 3-0 island growth mode to a 2-D layer-by-layer mode, through thermal
annealing. The transition layer between the substrate and epitaxial layers had
electron density equal to that of Ga2Te 3 and the thickness became thinner after
the annealing. However, diffusion of Te into GaAs layers was a lso induced throughthe treatment.
Email : crystal@ph.noda.sut.ac.jp

AS-16
CRYSTAL STRUCTURE OF BanLa4Ti3+n012+3n HOMOWGOUS COMPOUNDS

Hitoshi Ohsato, Takashi Okawa*, Yutaka Kobayashi , and Andrei Kirianov.
(Materials Science and Engineering, Nagoya Institute of Technology. Gokiso-cho . .
Showa-ku, Nagoya 466-8555, Japan. *Daiken Chemical Co .. Ltd, 2-7-9 HanatenNishi, Joto-ku, Osaka 536-0011 , Japan)
The homologous BanLa 4Ti 3+n0 12+3 n compounds are one of the microwave
dielectric ceramics which are key devices holding the information technology.
They have excellent microwave dielectric properties such as high dielectric
constant 8r =45, high quality factor Qf =45000GHz and low temperature
coefficient of resonant frequency ·y =-10ppm/C. The BanLa 4Ti3+nOl2+3ncompounds exist on the tie line BaTi0 3-La4Ti 30 12 in the Ba0-La20 3-Ti0 2 systembeside tungstenbronze-type like Ba 6 _3xRs+ 2xTi 180 54 (R=rare earth) solid solutions .
There are three kinds of compounds : n=1, BaLa4Ti 40 15 ; n=2, Ba2La 4Ti 50 1s ;n=4, Ba4La4Ti7024·
We got single crystals of n=1, BaLa4Ti 40 15 grown by self-flux method. The
crystallographic data are space groul?: P31 c or P31 c, Crystal system: trigonal,
Lattice parameters: a=5 .57A. c=22 .45A. We will present crystal structure modelsof the homologous compound: n=1, BaLa4Ti 40 15 . These compounds have thelayered hexagonal perovskite-like structure, which has a common sub-structurein the crystal structure. There are hexagonal layer included octahedra contactedwith face of polyhedron, and cubic layer included octahedra contacted with
apexes.
Email : ohsato@mse.nitech.ac.jp

A5- 17

SYNTHESIS AND CRYSTAL STRUCTURE OF Ga 2 (P0 4 h(4,4'-bipy}, A NOVELGALLIUM PHOSPHATE CONTAINING EXCLUSIVELY FIVE-COORDINATEDGALLIUM

Hsiu-Mei Lin,a Ching-Yeh Chenb and Kwang-hwa Lii*a,b arnstitute of Chemistry,
Academia · Sinica, Nankang, Taipei, Taiwan 115, R.O.C. bOepartment ofChemistry. National Central University, Chungli, Taiwan 320, R.O.C.
A new gallium phosphate. Ga 2 (P0 4 h(4,4'-bipy). has been synthesized by heating areaction mixture of Ga(N0 3 l3·4H 2 0, 4,4'-bipyridine, H 3 P0 4 • tetraethylammonium
bromide and water under hydrothermal conditions. The resulting product consistsof colorless plate-shaped crystals of the title compound in 73% yield. Its structure
has been determined by single crystal X-ray diffraction. Crystal data: triclinic,
space group P-1. a= 4.9723(9). b = 5.770(1). c = 11.812(2) A. a.= 78.268(3), ~ =89.159(3). y = 88 .344(3) 0 , V = 331.7(2) A3. Z = 1, and R1 = 0.0377. The structure
consists of neutral sheets of gallium phosphate which are pillared through 4,4'bipyridine ligands. A unique structural feature is that each gallium is coordinatedby one 4,4'-bipyridine and four phosphate ligands to form a Ga0 4 N trigonal
bipyramid . It is one of the few examples in which the gallium atoms are
exclusively five-coordinate . The synthesis and crystal structure of the title
compound will be presented .
Email : hmlin@chem.sinica.edu.tw

AS-18

1HE NONLINEARITY, BICRYSTAL FORMATION AND STRUCTURE IN KTiOP04
AND ITS ANALOGUE CRYSTALS*Jiyang WANG, Xiaobo HU, Yaogang LIUState Key Lab of Crystal Materials,
Shandong University, Ji'nan 250100, People's Republic of China. S .
Haussuehl,lnstitute of Crystallography, University of Cologne, Germany.
KTiOP0 4 (KTP) is an excellent nonlinear optical crystal for second-harmonic
generation of lasers . We have successfully grown large size and optical quality
KTP crystal by using flux method. During the growth process, the formation of
bicrystal structure in KTP crystal was observed and then confirmed by etching
method.
Many attempts have been undertaken to grow KTP analogue crystals by doping
and varying the chemical compositions of KTP crystal. We have grown RbTiOP0 4(RTP), KTi0As0 4 (KTA), RbTiOAs0 4 (RTA) single crystals and KTP crystals withdifferent dopants such as Nb, Na, Ga, Cr, Fe, Mn, Zn and rare-earth metals.
In this paper, we report the observation of a bicrystal structure. A simple model is
proposed to explain the formation of the bicrystal structure in KTP crystals. The
relationships between bicrystal structure and crystal properties are discussed .
Growth morphology, defects and nonlinearities of KTP analogue crystals are also
reported in the paper. The relationship between structure and physical properties
is discussed.
Email : jywang@icm.sdu.edu.cn

A5-19CRYSTAL STRUCTIJRE OF 1WO POTENTIAL BATI'ERY CATIIODES
K. SethuSankara b.

M.M. Govindb c
D. Velmuruganb, S. Saravanand , S .
Narasinga Raoe . aDepartment of Physics, RKM Vivekananda College, Chennai04. bDepartment of Crystallography and Bio-Physics, University of Madra s,
Guindy campus, Chennai-25, cnepartment of Physics, S.I.V.E.T College, Chenna i601302., dDeparment of Organic Chemistry, University of Madras,
Guindycampus, Chennai-25 and euniversity of central Oklahoma, USA.
Nitro compounds are well known for their explosive and electrochemical
properties. They are excellent precursors for aromatic amines (dyes) andmedicinally important compounds. The new synthetic methodologies for polynitro
compounds are of much importance in chemical industries and defence research
today. ()(-Nitrostilbenes are excellent precursors for f3 - phenylethylamines which
possess important biological activities . The studies on the crystal structure ofcompound (1) and (2) will help in understanding the detailed conformation of themolecules.
Crystal data are as follows: compound (1) C 14 H 8 N4 0 8 ,Monoclinic, P2lfc, a= 8.289(1), b= 11.353(2), c=16.716(2) A, f3 =100.74(1) 0 ,V=1545 .5(4) A3 and Z= 4 . Compound (2) C 1s H10 N4 010 Monoclinic, P2 1 /c a=
7.0964(1), b= 8 .550(3), c=28 . 101(5) A, f3 =90.87(3) 0 , V=1704.7(1) A3 and Z= 4. The
structures were solved by direct methods procedure using SHELXS97 program
and refined using the full matrix least squares technique using SHELXL97. The
final R- factor for compound (1) is 0.079 for 3836 symmetry independent [I >2cr(l)] reflections and for compound (2) is 0.052 for 31 OS symmetry independent [I> 2cr(l)] reflections. The details of the structural aspects will be presented.
Email: ksethu@md3.vsnl.net.in

AS-20CRYSTAL GROWTH AND X-RAY STRUCTIJRAL REFINEMENT OF POTASSIUM
ACID PH1HALA1E SINGLE CRYSTALSK. Srinivasana and P. Ramasamyb, acrystal Research Centre, Alagappa University,
Karaikudi-630 003. Tamil Nadu. India, bCrystal Growth Centre, Anna University,
Chennai-600 025, Tamil Nadu, India.

Potassium Acid Phthalate, is also known as KAP, is a good electro-optic and nonlinear optical material and also used as an analyzer material in X-ray
spectroscopy. It is a semi-organic compound, crystallizes from its aqueous
solution. Habitual morphology of the KAP crystal has 14 natural growth faces
with dominating (0 10) plane . In the present investigation, KAP single crystals ofgood optical quality were grown by solution growth methods. Solubility of KAP ina range of temperature was determined and Solubility coefficients at different
temperatures were calculated. The stability of the solutions in theirsupersaturated region was judged by measuring their metastable zone width by
nucleation method. A novel method to enhance the metastable zone width byincorporating chelating agents was first time introduced into the world literature.
The grown crystals were subjected to X-ray single crystal structural refinement
analysis. X-ray data were collected at room temperature on a Siemens AED single
crystal diffractometer using CuKa radiation (1= 1. 541 78A) in the q range 3-70°. In
total, 861 reflections were collected and a check was monitored for every 100
reflections. The data were corrected for Lorentz and Polarization effects. The basic
structure was refined using SHELX93 and the geometry of the molecules wasdetermined using Crysruler package and the drawing was obtained through
ORTEP3 program. The refined KAP structure belongs to orthorhombic system withspace group Pca21. The cell constants are: a=9.622A. b= 13.329A and c=6.468A
and the cell volume is 829 A3. The "R" factor for the entire refinement was 0.076.
Results will be presented in detail.
Email: nivas_5@yahoo .com

A5-21SWDIES ON NIOBIUM SUBSTITUTED HEXAGONAL CESIUM WNGSTEN
BRONZES

K.R.Dey 1 , A. Hussain I, C.H.Ruscher2· l Department of Chemistry. University of
Dhaka. Dhaka -1000 , Bangladesh. 2Institut fUr Mineralogic
Universitat
Hannover. Welfengarten 1 . D-30167 Hannover. Germany.
Tungsten bronzes are well-studied non-stoichiometric compounds having
interesting chemical and physical properties 1 . Bronzoids are fully or partly
oxidised analogues of bronzes, which are subjects of recent investigations 2.
Niobium substituted hexagonal tungsten bronzoids. MxNbyW 1_y03. where M= K
and Rb have been reported recently3.4.
Samples of CsxNbyW 1 _y0 3 with x= 0.25. 0.3 andy ~0 . 20 have been prepared fromappropriate amounts of Cs 2W0 4 , W0 3 .W0 2 and Nb 20 5 at 800°C by solid statemethod. The samples were examined by optical microscope and also characterizedby X-ray powder diffraction and spectroscopic methods.
The x-ray powder pattern of the samples reveal that Hexagonal Tungsten Bronze(HTB) type compounds could be synthesized with x = 0.25 and 0~30 and y ~ 0.1 .
The cell parameters increase with increasing niobium content, however, the .!!
value shows some scattering. The optical reflectivity of the powder samples of
CsxNbyW 1_y0 3 can be explained by Drude- free carrier model. The IR spectra of
the pure Cs-HTB with x;?: 0.25 show metallic behavior with very low absorption .
But the peak intensity of the spectra of niobium substituted Cs-HTB increases
with increasing niobium content due to the decrease in carrier concentration.
l. Ph.Labbe. (1992) Key Engineering Materials. 68,293-339.
2 . Magneli , A. (1989) 12th European Crystallographic meeting, Moscow.
3. Gesing, Th.M .. Ruscher . C.H. a nd Hussain, A. (2001) Z. l'.ristallogr.NCS.
216,37-38.
4. Hussa in, A.. Ul-Monir, A., Murshed, M.M . and Ruscher,C.H. (in press) Z .
a norg. allg.Chem.

Email : nitub@bangla. n etAS-22

1HERMALLY INDUCED RESIDUAL CHANGES IN 1HE CRYSTAL S1RUCTURAL
CHARACTERISTICS OF SOME POLYMERSAnjana Jain and Kalyani Vijayan, Materials Science Division, National Aerospace
Laboratories, Bangalore 560 017, India.
Polymeric materials have an extensive range of applications, which may include
repetitive use at elevated temperatures. Do repeated thermal exposures affect theinitial structural characteristics? From a detailed study of five polymers exposed
to temperatures in the range 150 to 700°C for durations ranging from lOs to-7000h, it has been established that the parameters intensity, 28. halfwidth andazimuthal spread of X-ray reflections manifest significant residual effects. The
shifts in the above mentioned parameters indicate introduction of changes in thephysical characteristics viz., crystallinity, unit cell dimensions, crystallite size
and/or microstrain and degree of molecular alignment respectively. As a typicalexample, it may be mentioned that after 1700 h of cumulative ageing at theconstant temperature of 250°C, the high strength, high modulus aramid fibre
Kevlar 49 loses -50% of its X-ray crystallinity. Such a reduction implies
deterioration in the exceptionally good initial tensile characteristics of the fibre,
which has also been confirmed experimentally. Details of the residual effects ofthermal ageing on the crystallographic characteristics of the polymers Kevlar,
Nomex, Twaron, Nylon6,6 and Teflon have been studied in detail and this paper
summarizes the results. The residual effects are indeed distinct from changes
associated with phase transformations.
Email: kavi@css.cmmacs.emet.in

AS-23

X-RAY FIBER DIFFRACTIONCOMPLEXS'IUDY ON

CHITOSAN/HYDROIODIC

ACID

K. Noguchia, S . Yokoyamaa, Y. Hanafusaa, K. Okuyamaa and K. Ogawab, aFacultyof Technology, Tokyo University of Agriculture and Technology, Koganei, Tokyo
184-8588, Japan, and bResearch Institute for Advanced Science and Technology,
Osaka Prefecture University, Sakai, Osaka 593 , JAPAN

Crystal structures of two polymorphs of chitosan/hydroiodic acid(HI) complex
were investigated by X-ray diffraction.
One of the polymorphs (form I, fiber
repeat= 10.26A) was obtained by immersing tendon chitosan in a colorless 6M HI
aqueous solution for 20 minutes at room temperature. The other (form II, fiber
repeat=39.85A) was prepared by immersing in a brownish HI aqueous solution for
24 hours at 4'C. All the 39 observed reflections of the form I could be indexed interms of a monoclinic unit cell with dimensions of a=9 .43(3), b=9 .86(2), c(fiberaxis)=10.26(3)A, and ~=105.1(2)'. The intensity distribution in the fiber pattern
together with the cylindrical Patterson map of the form I indicated that C ionswere aligned along the c-axis at about 5A interval and make a columnar
structure. After locating r ions, the positions of chitosan were examined by thedifference Fourier map. The sites of the C ions in the unit cell were very close to
those of the water molecules in the hydrated form of chitosan.
In addition,
crystal structure of chitosan/HI form I was quite similar to that of chitosan/nitricacid complex.
It was suggested that the columnar structure of water in thehydrated form plays an important role for the complex formation.
Email: knoguchi@cc.tuat.ac.jp

AS-24

STRUCTURALSTUDIESOF ATOMIC .ARRANGEMENTSAND
MAGNETIC
CORRElATIONS IN PT-RICH PT-MN ALLOYS BY DIFFRACTION TECHNIQUES
K. Ohshimaa, M. Takahashia, T. Sembiringa, T. Shishidob, arnstitute of Materials

Science, University of Tsukuba, Tsukuba 305-8573, Japan, blnstitute for Materials
Research, Tohoku University, Sendai 980-8577, Japan.
APt-rich Pt-Mn alloy system has been known for a long time to have a Cu:0-u orderedstructure (L1 2 ) below the order-disorder transition temperature, Tc, whose regions
extend from 10 to 35 at. % Mn. Several structural chara cteristics in Pt-rich Pt-Mn alloy
system h ave been newly found with the use of electron, X-ray and neutron diffraction
techniques. A cubic ABC 6 -type ordered structure exists in a composition range between
12 and 14 at.% Mn below 900 K, where A, B and C correspond to MnxPtl-x• PtxMnl -x
and Pt (x>1/2), respectively. A two-step phase transition from ABC 6 -type structure toL1 2 and from L1 2 to A1 appears in this narrow composition range. The shape ofmagnetic diffuse scattering below room temperature strongly depends on both the heat
treatment and the composition. For Pt-12 at. % Mn, diffuse maximum is observed at(l /2,0 ,0), which is due to short-ranged spin-density wave correlation originated by
nesting a Fermi surface in the disordered state. In the ordered state , split diffuse
maxima are also observed at (1/2, 1/2,0) and (1/2,0,0). A Fermi surface nesting effect isenhanced due to the development of the atomic long-range ordering. For Pt-14 at.% Mnalloy, magnetic superlattice reflections appear at (1/2,1/4 ,0) and its equivalent
positions in addition to the weak magnetic diffuse scattering ; the antiferromagnetic
ordering appears below 20 K. For Pt-16 at.%. Mn alloy, there was no magnetic diffuse
scattering. It is realized that there are strong relations between the atomic arrangement
and magnetic correlations in Pt-rich Pt-Mn alloys.
Email : ohshima@bk.tsukuba.ac.jp

A5-25
1HE INFLUENCE OF DIVALENT ELEMENTS (A'=Sr, Ca) ON CRYSTALS1RUC1URE AND MAGNETIC PROPERTIES OF La 1 _~'xMn0 3 (O<x<0.5) .

Le Thi Cat Tuong and Phan Vinh Phuc. Institute of Materials Science, Hoang

Quae Viet street, Cau giay, Hanoi, Vietnam
In La 1 _xA'xMn0 3 (A'=Sr, Ca), when the La3 + is progressively substituted bydivalent cations, the proportion of Mn 4 + increases and this leads to a change inmagnetic properties, crystal structure and other properties. In this paper westudy the influence of Sr2 + and Ca2 + with various contents on crystal structure
and magnetic properties of La 1_xA'xMn0 3 . The Mn 4 + content and some lattice
parameters were calculated from results of Rietveld refmement of crystal structurewith x-ray powder d iffraction data. The obtained results were also used to explain
magnetic properties of these materials.
Email : nbaan@netnam .org.vn, pvphuc@ims.ncst.ac.vn

.AS-26

IMPROVEMENT OF MECHANICAL PROPERTIES OF FERRO CAST DUCTllE 60
IRON TO ADI WI'IHOUT HEAT 1REATMENT

Lukito, Bambang Soegijono, Muhammad Hikam Material Science Program,
Jl. Salemba Raya No 4
Department of Physics, University of Indonesia
Jakarta 10430. Indonesia
The nodular ductile iron is increasingly being used due to the benefits it offers
over other alternatives, especially in vibrational absorbtion. Here we report a
study of Ferrocast ductile FCD 60 (whose main elements are 3.5 % C. 2.5 % Si,
0 .02 % P , 0.5 % Mn. 0.02 %S. and 0.3 % Cu ). a material used in the Front Hub ofMercedez cars . The tensile strength of FCD was 60 600 Njmm2 and its elongation
was 6%. The common methods to change the mechanical behaviour of a material
are to use the heat treatment process or to add an alloy. Here we aim to obtaincore nodular Austemper Ductile Iron (JIS G 5503, atleast 900 N /mm 2 tensile
strength and an elongation of 4%) without either the heat treatment or adding an
alloy. The method used here is to increase the proportion of Mn to 0.9% and Cu to
0.5%. Various analyses carried out through X-ray flouresence, X-ray diffraction ,scanning electron microscopy and Gas chromatography (RADIOGRAPHY TEST)
reveal an average tensile strength of 898.10 N/mm2, an elongation of 5.87% and ahardness of 263 HB for the nodular ductile iron, thus obtained, comparison with
the JIS standards suggest that the mechanical behaviour of the material has
approached that of the lowest level of Austemper Ductile Iron.
Email : lukie@yexa.eng.ui.ac.idAS-27RElATIONSHIP BE1WEEN ISOMERIZATION OF HOST FRAMEWORKS AND
PACKING COEFFICIENTS OF HOST CAVTI1ES IN ORGANIC POROUS CRYSTALS

Masashi Shigesatoa, Nungruethai Yoswathananonta. Kazuki Sadaa, Mikiji Miyataa,
Kazunori Nakanob, Kohji Tashiroc. aMaterial and Life Science Graduate School ofEngineering, Osaka University, Yamadaoka2-1, Suita, Osaka 565-0871,Japan,bNagoya Municipal Industrial Research Institute, 6-3-4-41 Atsuta. Nagoya, Aichi
456-0058, Japan, cGraduate School of Science, Osaka University, l-1
Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
Polymolecular hosts are built with noncovalent bonds. It is difficult to design ahd
construct host frameworks on purpose, because the frameworks change
significantly according to molecular structures of host and guest molecules. Here
we report a systematic & quantitative study of molecular recognition of steroidal
bile acids by using a parameter called Packing Coefficients of host cavities(PCcavttyl · PCcavity is the ratio of the volume of host cavity to the volume of guest
molecules. We found the correlation between the framework isomerizations andPCcavity in a series of inclusion compounds of cholic acid with monosubstituted
benzenes. We have previously reported that the PCcavity are in the small range of
55 - 70%. Here, we report correlations between host framework isomerizations
and PCcavity in various inclusion crystals of organic porous compounds withvarious guests. Organic porous compounds change the host frameworks and/ or
the host-guest ratios to fit the shape and volume of guest molecules.
It isassumed that PCcavtty of all the organic porous compounds are in the small range.
Stability of organic porous inclusion crystals depends on the PCcavity· However
hosts with hydrogen bonds between hosts and guests have relative larger range ofPCcavity than hosts without hydrogen bonds between hosts and guests . This isbecause the hydrogen bonds between hosts and guests expand the PCcavtty·
Email : shigesa@ap.chem.eng.osaka-u.ac.jp

A5-28

EFFECT OF Pb ON CRYSTALLOGRAPIDC STRUCTURE AND
DENSTIY OF Ba 1 _xPbxTi03 CERAMIC WITH x (NOMINAL) = 0.5

ELECTRON

Bambang Soegijono, Nofrijon, Muhammad Hikam, Materials Science Program,
Department of Physics, University of Indonesia, Jl. Salemba Raya No 4 Jakarta
10430, Indonesia.
The effect of Pb on crystallographic structure and electron density of Ba 1 _xPbxTi03
ceramic, where x (nominal) = 0.5, has been investigated . The samples weresynthesized using powder metallurgy method from BaC03. PbC03 and Ti02. withpurity better than 99%, available commercially from E-Merck. The X-ray
diffractograms obtained at room temperature were refined using the
crystallographic software package GSAS. Structural analysis shows that the
crystal is Bao. 7 Pb 0 .3Ti0 3 with the perovskite-type BaTi0 3 structure, the spacegroup tetragonal P4mm, a= 3.943(1) A, c = 4.055, V = 63.035 A3 with 19 refined
variables , the goodness of fit x2 is of 2.115 and the residual parameters Rp and
Rwp are of 18.630% and 23.640% respectively. These results Lrnply that Pb has noeffect on the non-centrosymmetric structural change of barium titanate, except tocontract a and b parameters and to extend c parameter with c/ a ratio to 1.03.
Studies on electron density show that the electron density measurements are
consistent with the calculated structural parameters with maximum ~p = 7 .965
eA-3 and minimum ~p = -2.555 eA-3. The final results show that there is anincrease in electron density at the substitute ion positions with maximum p =180.069 eA-3 and 172,105 eA-3 for the observed and the calculated value
respectively. The.se values are greater than the one from barium titanate. There is· approximately 56% (53%) increase in observed (calculated) maximum electron
density as compared to an approximate 33% when Pb substitutes Ba.
Keyword: barium titanate , lead titanate. X-ray diffraction, electron density

Email: hikam@fisika.ui .ac.idA5-29GROWTII OF lflGH DENSI'IY GRAPHITIC NANOTIJBES (GNT) AND TIIEIRSTRUCTIJRAL/ MICROSTRUCTIJRAL CHARACTERIZATION

Anchal Srivastava and O.N. Srivastava. Deptt. Of Physics. Banaras Hindu Univ.
Varanasi- 221005, India
In the present investigation, the controlled high density multi walled aligned
carbon nanotubes bundles have been synthesized by pyrolyzing a spray solution
of Ferrocene (Fe(C5H5]2 and Benzene [C6H6] in an Ar atmosphere at -900oC . A
Carbonious hollow cylinder containing high density aligned GNT of length -Scmand thickness 0.1 mm with outer and inner diameters are 1 em and 9cm has
produced. The GNT grows in redial direction of the cylinder. Scanning electron
microscope (SEM) images show that the optimum length of tube bundles is very
long and approaches -0 . 1 mm. The bright field (BF) and dark field (DF) images oftransmission electron microscope (TEM) show that Iron (Fe) has encapsulated
inside the tubes during synthesis process Selected Area Diffraction Pattem (SAD)
confirms that Fe exist in side the tube in crystalline form (bee) having lattice
parameter 2. 8664A.
Email: hepons@yahoo.com

A5-30FLUXED MELT TECHNIQUE OF CRYSTAL GROWTII AS APPLIED TO OXIDECRYSTALS -A BRIEF REVIEW

P.N.Kotru, Crystal Growth & Materials Research Group, Dept. of Physics &Electronics, Univ. of Jammu, Jammu- 180 006 (India).
Fluxed melt technique of crystal growth has established versatility in obtaining
single crystal growth of a wide range of materials. The salient features of thistechnique with special reference to oxide crystals bearing perovskite andhexagonal structures are described. The main objective of growing crystals in thelaboratory is to achieve high quality materials for device applications and forscientific investigations. Assessment of their physical and chemical perfection
through various probes is essential. Flux growth has the advantage of producing
facetted crystal, thus making it possible to use optical and scanning electron
microscopy supplemented by energy dispersive X-ray analysis (EDAX) as anintegrated method of investigating the defect structures in the crystals. Ra re ea rthperovskite structured crystals of RA10 3 , RCr0 3 & RFe0 3 are interesting materia ls
on account of their optical and magnetic properties. Ferrites, in general, aretechnical materials which find applications as permanent magnets, magnetic
recording, computer, microwave communication devices, radios and televisions ,telecommunication and other uses as in copying devices. magnetostrictive
vibrators, electromagnet cores etc. Application of hexaferrites in devices operating
at higher microwave and mm- wave frequencies is interesting. The renewal ofinterest in hexaferrites as "classical high frequency ferrites" has been realized. The
devices of these types require high quality crystals. The development of growthtechnology of perfect single crystals either in the form of bulk or of thin epitaxial
films is of immense importance. The LPE growth of hexaferrites requires asuitable and perfect substrate . The defect characterization of rare earth perovskite
structured crystals (RA10 3 , RFe0 3 & RCr0 3 ) and substituted/ unsubstituted
hexaferrites using surface methods like optical and scanning electron microscopy
supplemented by EDAX techniques and etching as well as bulk methods such as
X- ray topography is described and discussed. The defects and sources thatgenerated them are traced. The major challenges in the fluxed melt growth of very
perfect crystals are identified.
Email: pn_kotru@yahoo.com

A5-31DISWCATION ETCHING STUDIES ON NATURAL NATROLITE CRYSTALS.

P.R.Dhar, K.K.Bamzai, P.N.Kotru, Crystal Growth & Materials Research Group,
Dept. of Physics & Electronics, Univ. of Jammu, Jammu- 180006.
Natrolite bearing chemical composition as Na 2Al 2 Si3 0 10 . 2H2 0 belongs tonatrolite group having an orthorhombic structure. It exhibits cleavage along m(110) and b (010). the former being much more perfect than the latter. Etchingexperiments on (110) cleavages of natural natrolite crystals have been performed,
taking different concentrations of H 3 P0 4 in the range of 5-40% at different
temperatures ranging from 20 to 80°C. Effect of concentration and temperatureon the depth and lateral extension of etch pits is critically studied . Velocities of
etching along and perpendicular to (110) surfaces at different temperatures andconcentrations are calculated. The results of etching kinetics are presented anddiscussed. It is reported that the etching behaviour follows Arrhenius equation.
The Arrhenius factor and activation energies are calculated. It is reported that
10% H 3 P0 4 at 40oc yields best results so far as etching is concerned. The
dislocation densities are measured. Co'm parison of etching of indented andunindented cleaved (110) planes of natrolite is presented. It is reported thatthough the dissolution rate of area around indentation is greatly enhanced, it
does not increase the density of dislocations . The implications are discussed.
Email: pr_dhar@rediffmail.com

A5-32AN OVERVIEW OF SOME SUBSTIW1ED BIPHENYLS IN RESPECT OF THEffi
SINGLE CRYSTAL GROWTH AND X-RAY CRYSTAL S1RUCWRE ANALYSIS

Rajnikant. V. K. Gupta, Dinesh and Ashok Kuma r. Crystallography Laboratory,
Department of Physics. University of Jammu. Jammu Tawi- 180 006, India .
There is scant availability of literature on the single crystal growth an d Lhreedimensiona l structural aspects of substituted biphenyls . The work re porled inthis paper is an overview of three separate studies carried out on two kind s ofsubstituted biphenyls i.e. 2,3,4-monosubstituted and 4,4'- linearly chained
biphenyls (Liquid Crystals), with an aim to prepare X-ray diffraction qua li ty s ingle
crystals of a series of chemically-similar-looking substances using s low
evaporation and vapor precipitation techniques, and determining the th ree dimensional structures of the grown materials using X-ray Crystallogra phic andComputational techniques. The study being reported is first of its kind on a seriesof biphenyl systems where an attempt has been made to:i)investigate the role of solvent system in achieving quality crys ta lliza ti on .
ii)
Study the phenomenon of polymorphism and multiple mol ec u les inbiphenyls .
iii)
obtain the three-dimensional molecular and crystal structures .
iv)
Study molecular packing, and·v)
establish a correlation between the solvent system, crystal qu ality andcrystal structure
Email : rkantverma@rediffmail.com

A5-33

DIELECTRIC AND MECHANICAL CHARACTERIZATION OF SAMARiuM DOPEDLEAD TITANATE CERAMICS.

Rave nder Tickooa, K.K.BamzaP, R.P.Tandonb and P.N.Kotrua , a CGMR Lab.
De partment of Physics and Electronics, University of Jammu, Jammu b
De partment of Physics and Astro-Physics University of Delhi. Delhi.
Modified lead titanate ceramics have emerged as promising materials forpi ezoelectric applications owing to large electro-mechanical anisotropy in the
coupling factors a long transverse direction of polarization. These modified
mate rials have potential for high frequency applications. Samarium doped leadtitanate ceramic compositions (containing 2-20% samarium) have been preparedusing solid state reaction method. Dielectric studies show peaks at transition
temperature in a ll compositions: the magnitude of peak width being dependent on
the frequency of measurement. The transition temperature decreases at t.he rateof -12° C/mol% of samarium substitution. Mechanical characteristics of theseceramic samples were investigated using Vicker's Microhardness testing device.
The value of microhardness (Hvl is observed to be dependent on load applied. Hvdecreases rapidly in the load range of 0.1 to 0.5 N and thereafter achieves
saturation. The behaviour of the dependence of Hv on load (0 . l to 1 N) is similar in
all concentrations of the dopant (Sm) compositions, a lthough the maximum valueof hardness increases with the increase in the concentration of samarium. The
behaviour of Hv Vs load is not in accordance with the Kick's law. but thecalculations indicate applicability of Hays and Kendall's law. The load
independent values are calculated using the latter. The micro hardness analysis
and the laws applicable are described and discussed.
Email: ravender_tickoo@yahoo.com

AS-34

BULK CRYSTALS TO Fll.MS : X-RAY DIFFRACTION TO PROBE 1HE S'IRUCTIJREOF PSUEDOBINARY ANTIMONY 1ELLURIDE

S . N. Dhar. C. F. Desai and N. C. Chourasia* . Physics Department, Faculty of
Science,
M.S .UniversityofBaroda,Vadodara
390
002,
Gujarat,India. *Department of Metallurgy, Faculty of Engg. & Technology, M.S. University of
Baroda, Vadodara. Gujarat, India . .
The V2VI3 compounds like Bi2Te 3, Sb 2Te3 and Bi2Se3 are narrow band gap
semiconductors having rhombohedral layer type crystal and display interesting
thermoelectric properties. Amongst these Sb 2Te3 has been found to exhibit p-typeconduction, which no dopant has been found to change ton-type. In an attempt
to improve its thermoelectric properties, the purpose of the present study was toexplore a new aspect of this problem- namely, the interchange of atoms with thesame nominal valence state between structures of different atomic symmetry. In
particular, we have been concerned with the possible interchange of Bi or In with
Sb between Bi2Te3 or In2Te3 and Sb2Te3.
X-ray diffraction ·i s a tool which has been used for investigation of the physicalperfection of the pseudobinary solid solution. The X-ray pattern for bulk and thinfilms of the crystals were obtained for 28 angles between 20° and 60° forstructural determination and to differentiate between phases having the samechemical composition but different crystal structure. The peaks in the powder
pattern of Sb 2Te3 were compared with those in the JCPDS data card and were
found to match readily. The other powder patterns were indexed and the lattice
parameters were evaluated. The patterns show no new peaks introduced by Bi
and In indicating that Bi and In have assumed substitutional positions in the
Sb 2Te3 lattice. The crystallite size was evaluated for films of different thicknesses
from the Full Width Half Maximum (FWHM) of the highest peak of the X-ray
pattern of as-deposited and annealed films . While no reflections corresponding to
the free elements were detected in the case of powder pattern and as depositedfilms. the annealed films show the characteristic peaks of free tellurium. The
results are discussed in the paper.
Email: sumidhar72@yahoo .com

.AS-35SPHERUU'llC
GROWTIIHEPTAMOLYBYDA'IESOF

SINGLE

AND

MIXED

RARE

EARnl

Sanjay Pandita, Vinay Hangloo, K.K.Bamzai, P.N.Kotru and Neera Sahni*. CGMR
Lab., Department of Physics & Electronics, University of Jammu, Jammu-180006 (India), *Department of Geology, Panjab University, Chandigarh - 160 014(India)Rare Earth Molybdates, in general, have the potential of wide application inscience and technology on account of their fluorescent, laser. piezoelectric,
ferroelastic and ferroelectric properties. The rare earth molybdates bearing
a general formula R 2 (Mo0 4 b have been acknowledged as ferroelectric materials.
The growth of single crystals of praseodymium heptamolybdate and mixed
crystals of didymium heptamolybdates is accomplished, by allowing controlled
diffusion of rare earth ions through silica gel impregnated with the lower reactant
providing molybdenum ions. The system used is RC1 3 - (NH 4 ) 6 Mo 7 0 24 - NH 4 N03 HN0 3 - Na 2 Si03 (where R = Pr and Di). The grown crystals were characterized byusing various characterization techniques, which include EDAX, XRD, IR, XRF,
Scanning and Optical microscopy and Thermal analysis. The crystals assume
varied morphologies including platelets, cuboids and spherulites. Spherulitic
growth of praseodymium and didymium is found to be different as that ofgadolinium heptamolybdate. The results are presented and discussed.
Email: s_pandita@ rediffmail.com

A5-36

CRYSTALWGRAPlllC CHARACTERIZATION OF KNb0 3 1HIN FILMS GROWN ON
SrTi03 SUBS1RATES BY LIQUID PHASE EPITAXY

Shirnou Ito, Izumi Masuda, Ken-ichi Kakimoto, Hitoshi Ohsato, Nobuy8su
Adachi, Takashi Okuda, Nagoya Institute of Technology, Gokiso-cho, Showa -ku .
Nagoya, 466-8555,Japan
KNb0 3 is one of the materials being expected as high-performance lead-freepiezoelectric materials in place of the PZT ceramics. Applica tion of this materia lwill make it possible to decrease the size and improve the performance of thepresent electronic machine in such cases as the SAW (Surface Acoustic Wave)filter and the SHG (Second-harmonic generation) element. Because it has suchcharacteristics, we paid attention to a KNb0 3 single crystal thin film, and tried to
grow by means of liquid phase epitaxy (LPE). The high purity materials weremixed according to composition -52.5mol% K2 C0 3 (99.99% purity) and 47.5mol%
Nb 2 0 5 (99.9% purity) - in the platinum crucible, then melted above the meltingpoint and homogenized by stirring. A substrate (about lOmm x 5mm triangl eshapes, t=lmm) was dipped into the melt. It succeeded in growing a (001) KNb0 3
single crystal thin film on the (00 l) SrTi0 3 single crystal substrates as a resu lt. It
is reported about the growth process and evaluated epitaxial relationship bymeans of XRD.
Crystallographic data of KNb0 3 Perovskite-type structure, Space grope:
Bmm2(38). Crystal system: Orthorhombic Lattice parameters: a=3 .9 73A,
b=5.695A. c=5.721A Crystallographic data of SrTi0 3 Perovskite-type structure .
Space grope: Pm3m(22l). Crystal system: Cubic Lattice parameters: a=3.904A
Email : shinrou@mse .nitech.ac.jp

AS-37STUDY OF LATTICE DISTORTION IN UREA DOPED KDP SINGLE CRYSTALS BY
X-RAY DIFFRACTION STUDIESSupama Sen Gupta a nd S. P. Se n Gupta , Department of Materials Science,
Indian Association for the Cultiva tion of Science , Jad a vpur, Calcutta-700 032,
In d ia.
....

In view of th e higher non-linear responses, good thermal and mecha nical stability,a n a ll.e mp t has b een m a d e to grow single crystals of potassium dihydrogenorth oph os ph ate (KD P). d oped. with different mole concentrations of urea usings low eva po ra lio n techniqu e . The e ffect of impurities on the growth, surface
morphology. structura l. a nd optical prope rties have been investigated . With theincrease of dopant concentration (1M% to 10M%). it was found that the dopant
promotes the growth rate. X-ray diffra ction studies were carried out on the
crystals using a Philips X-ray diffractometer with Cu K.-, radiation. X-ray study
revealed that the structures of the doped crystals are slightly distorted ascompared to the pure KDP crystal. This may be attributed to lattice strains withth e adsorption of urea. FTIR and other studies will be carried out · to reveal thepresence of dopants in KDP.
Em a il : msss@ma h endra.iacs.res.in

AS-38MEASUREMENT OF lATTICE PARAMETERS IN SOME MIXED CRYSTALS OFAMMONIUM SULPHATE AND POTASSWM SULPHATE

Susmita Karan and S. P. Sen Gupta, Department of Materials Science,Indian
Association for the Cultivation of Science , Jadavpur, Calcutta-700 032 , India.
Ammonium Sulphate (AS) is a well-known ferroelectric having electro optic
properties. On the other hand, Potassium Sulphate (PS) is an antiferroelectric.
Both of them belong to the same 13-KzS04 family. Hence attempts have been madeto substitute ammonium ion (NH 4 +) by potassium ion (K+l to grow substitutional
mixed crystals of Ammonium-Potassium Sulphate. Mixed system of AS-PS, [KLx
(NH 4 lx bS04 were grown by the method of solvent-evaporation at an ambient
temperature of 25oc for molar concentration of ammonium in the range 0 ~ x ~1.0. X-ray powder diffraction pattems were recorded in a Philips micro-processor
controlled x-ray diffractometer (APD 1710) using nickel-filtered CuKa radiation(A.=l.54A) with an output power of (30kV, 20mA). The cell parameters, namely 'a'(A), 'b' (A), 'c' (A) and cell volume 'v' (A3 ) .of the mixed system with several molar
concentrations( X ) were determined using POWD program. It has been found that
all the three lattice parameters and the cell volume increase linearly with increasein x. The lattice parameters were also estimated theoretically using Vegard's law.
Composition dependence of lattice parameters (a and b) following the above law
shows good agreement with the experimental results. However, an appreciabledeviations from the above law exists in the lattice parameter 'c' which is the polar
axis of the crystal. From the packing consideration, this may be due tocomparably more elongation of the cell in 'c' direction than other two directions.
Emailmssk2@mahendra.iacs.res.in

AS-39CHARGE-ORBITAL ORDERING IN 1HE BlLAYER CMR MANGANITE ~Sr2Mn 20 7 .

Tapan Chattelji, Institute Laue-Langevin, Grenoble, France.
We have investigated the charge/orbital ordering in . 50% hole-doped bilayer
manganite La.Sr2 Mn 2 0 7 by X-ray and neutron diffraction on single crystals. Highenergy X-ray and neutron diffraction revealed superlattice reflections at positions
corresponding to the propagation vector k = (-1/4,1/4,0). Temperature variationof the superlattice reflection indicated the development of a coupledcharge/orbital ordering below Tc0 =225 K which starts melting at about the same
temperature at which A-type antiferromangnetic ordering (TN=170 K) sets in. The
intensity of the superlattice reflections becomes ve·r y small below about 100 K. A
reentrant behavior of the charge/orbital ordered phase has been observed below
about 50 K. We have investigated the resonance X-ray scattering from
La.Sr2 Mn 2 0 7 at the Mn K absorption edge. A strong enhancement of the intensityof the superlattice reflection at Q= (- 1/4,1/4,10) has been observed at the kabsorption edge of Mn. The polarization of the scattered reflection shows
oscillatory behavior between the a- a and a-n channels as a function of theazimuthal angle with a period of about 90 degrees. All these results will be
discussed in terms of newly developed theories of bilayer maganite.
Email : chatt@ill.fr

AS-40THE CREATION OF ''ISLANDS" INSIDEBOMBARDMENT OF THE ELEC1RON BEAMS

Sn(y)Ox~1HIN

FILMS

UNDER

V.Vonga, L.T.Hungb, aLaboratory of Electron Microscopy, National Centre for
Natural Science and Technology, HoangQuocViet Str. Caugiay Hanoi Vietnam andbOepartment of Physics, Chemnitz University D-091 07 Chemnitz, Germany.
SnOx-thin films are widely applied for use not only in many optoelectronic
devices, window heaters, electrodes for displays, but also in the field of gas
chemical sensors. They are either semicondutors or dielectric substances
depending on the amount of the oxygen (value of x in the formula). In recent years
the films were improved by additives ranging from usual metals such as Sb, Al, tonoble metals such as Ag, Pd, Pt. which has given rise to the fomula of al isSn(y)Ox ,in which y is the doped-material . In this work we have been using theelectron beams of the transmission electron microscope EM-125K to study
inelastic collisions inside of the Sn(y)Ox thin films . The TEM- pictures show thatthe islands were created under bombardment of electron beams. Size of the"islands" is less than 10 nanometres. The results also show that the islands
consist of two differential areas, which were represented and contrasted clearly by
black and white .The islands strongly influence the properties of the films .
Email : vvemlab@ncst.ac.vn

A5-41

EFFECT OF SUBS11TUTION ON THE GROWTii OF RARE EARTH MOLYBDATECRYSTALS

Vinay Hangloo, K.K.Bamzai, P.N.Kotru and Neera Sahni*. CGMR Lab.,
Department of Physics & Electronics, University of Jammu , J ammu-180 006(India}. *Department of Geology, Panjab University, Chandigarh - 160 014 (India)
Ra re earth molybdate crystals are technologically important crystals as thesecrystals possess interesting properties viz. , ferroelectric , ferroelastic , piezoelectric,
fluorescent and other important properties. In the present case, we have achieved
the growth of pure Gd-molybdate and substituted Gd-Ba-molybdate and Gd-Srmolybdate crystals, using the system RCl3 - (NH 4 )5Mo 7 02 4 - NH 4 N03 - HN03 Na2Si0 3 (where R=Gd, Gd:Ba, Gd :Sr). The grown crystals were characterized byusing various characterization techniques, which include EDAX, XRD, FTIR,
Scanning and Optical microscopy and Thermal analysis. It is observed that on
addition of Ba or Sr to pure Gd-molybdate crystals, the morphology gets
drastically changed. The pure Gd-molybdate grow as spherulites while as thesubstituted Gd-Ba-molybdate grow as well-facetted crystals. On the other hand
Gd-Sr-molybdate grows in the form of agglomerations of hexagonal crystallites
giving rise to sta r like shape, are illustrated. Experiments to make an in-depth
study of the changes that are brought about in the morphology of crystals on
addition of Ba and Sr are in progress. The implications are discussed.
Email: vinayhangloo@rediffma il.com

AS-42CHARAC1ERIZATION OF POLYCRYSTALLINE IRON SURFACE UNDER lfiGH'IEMPERAIDRE BY SMALL GlANCING ANGLE X-RAYS SCAT'IERING

Y. Fujiia, K. Koikea, T. Nakayamab, K. Yoshidaa, a Faculty of Engineering, Kobe
University, Kobe 657-8501. Japan, b Materials Research Laboratory, Kobe Steel,Ltd., Kobe 651-2271, Japan
Characterization of polycrystalline iron surfaces by small glancing angle X-ray
scattering has performed with use of a compact ultrahigh vacuum (UHV) X-ray
diffractometer. With use of this equipment we investigated mechanically polishedpure iron polycrystalline surfaces (ferrite, 3nines purity) before and after thebaking at 500 for 20 hr in a vacuum of I0-6 Pa. Angular distributions of thescattered x-ray intensity from them were measured at several glancing angle
incidence of the X-ray. A broadening of the scattered X-ray intensity profiles at
small glancing angle incidence of the X-ray appeared on the baked specimen. The
result of this experiment when compared with that of the simulation of somesurface structure models, gives some clues to estimate the surface roughness .
Based on these results, we propose a method of surface characterization.
·
Email : fujiiyos@kobe-u.ac.jp

A5-43ATS SCATIERING FROM CUPRITE, Cu 2 0

Yoshiyuki Ninomiya, Ayako Watanabe, Hidetaka Sawai, Jun Kokubun and
Kohtaro Ishida. Department of Physics, Faculty of Science and Technology, Tokyo
University of Science, Noda, Chiba 278-8510, Japan.
Using ATS scattering [1], we can obtain local information about anisotropic
environment for a specific atom. Though the scattering is very weak comparedwith Thomson scattering, we can obtain only an anisotropic factor by measuring a"forbidden" reflection because the isotropic part is excluded from the reflection.
Energy spectra of the ATS reflections of cuprite were measured near the Cu Kabsorption edge from 8 .941 keV to 9.023 keV. The spectra are distributed in avery wide range, over 50 eV, but there is no peak below the edge contrary to theobservation by Kirfel et al[2). The shapes of the energy spectra for the 001 and
003 reflections are essentially the same. This result indicates that these ATS
scattering are caused by dipole transition process . In fact, the observed azimuthal
dependence at 8.982 keV and 8.998 keV agrees with the curves calculated fromatomic scattering tensors of second rank. The magnitude of an off-diagonal
element of the scattering tensor for one copper atom is 1.9 electrons for the main
peak at 8.982 keV. This value is very large compared with that for one iron atom
in iron pyrite and magnetite, 0.2 and 0.3 electrons, respectively.[3,4) We presume
that this large anisotropic term is due to the anisotropic environment of thecopper atom with a strong linear coupling between oxygen atoms.
[1) V. E. Dmitrienko: Acta Cryst. A39 (1983) 29.
[2) A. Kirfel et al.: Acta Cryst. A47 (1991) 180.
[3) J . Kokubun et al.: J. Phys. Soc. Jpn . 67 (1998) 3114.
[4) K. Hagiwara et al.: J. Phys. Soc. Jpn. 68 (1999) 1592.
Email : crystal@ph.noda.sut.ac.jp

('A6 : Cry stall ogra phy in biology,:med icine ~nd pha nna colo gyA6-lA NOVEL REVERSED WOBBLE PAIRJNG OF OXIDIZED TIIYMINE RESIDUEWITH GUANINE RESIDUE IN B-FORM DNA, AND ITS BIOLOGICALSIGNIFICANCE

A. Takenakaa, M. Tsunodaa, T. Sakauea, S. Naitoa, T. Sunarnia, N. Karinob, Y.
Uenob. A. Matsudab, aGraduate School of Bioscience and Biotechnology, Tokyo
Institute of Technology, Yokohama 226-8501, Japan, and bGraduate School of
Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Activat~d oxygen atoms such as those of hydroxyl radicals, hydrogen peroxide andhydrogen superoxide anion radicals are potent mutagens. which produce several
damages in DNA. Thymine base is oxidized to form 5-formyluracil (f3U). In DNA
replication. f3U induces mis-incorporation of non-complementary nucleotide into
a newly synthesized DNA strand. To investigate the hydrogen-bonding property of
f3U residue. crystal structures of DNA dodecarners with the sequences ofd(CGCGXATf3UCGCG). where X is A or G, have been determined.
The
dodecarners are associated to form a B-form duplex so that f3U interacts witheither A and G. Electron density maps show that the f3U:A pairs occur only in the
Watson-Crick geometry, and that there are two types of f3U :G pairs. In the latter
cases, one is wobbled and the other is also wobbled , but in the opposite direction.
Such a reversed wobbling is a new type of pairing mode. Structure modeling of
DNA polymerase with DNA fragments containing f3U suggests that the WatsonCrick-type :f5U:A pair is acceptable in the enzyme with no structural interference,and that the wobble f3U:G pair is sterically hard to enter the binding site of the
enzyme, but the reversed wobble f3U :G pair is acceptable . This mis-incorporation
may induce mutagenesis.
Email : atakenak@bio. titech.ac.jp

A6-2
OPENING AND CLOSING OF THE ACTIVE STIE OF C. PERFRINGENS ALPHATOXIN BY ITS LOOP MOVEMENT ·- IS IT 'IRIGGERED BY MEMBRANE
BINDING OR BY CALCIUM?

Ajit K. Basak 1 ,_A. Cole 1 , C . E. Naylor 1 , D. S. Mossl , J. Miller2, and R. W.
1'itball2. 1 Deptartment Of Crystallography, Birkbeck college, Malet Street,
London WClE 7HX, 2Defence Science and Technology Laboratory, CBS Porton
Down . Salisbury, Wiltshire SP4 OJQ , UK

Clostridium perfringens is a gram-positive anaerobic ubiquitous bacterium andsecretes a range of t9xins of which the a-toxin is the key determinant in gas
gangrene and also implicated to several other diseases in man and animals .
Alpha-toxin is secreted by the bacterium, and lowers the oxygen pressure intissues, allowing the proliferation of the bacterium. Tissue necrosis occurs at
the rate of a few cm/hr and is accompanied by a foul smelling exudate, which isthe product of anaerobic fermentation , toxemia, and finally death with in few
days. The only treatment is high dose of antibiotics or amputation of the organs.
The toxin is a 370'- residue, zinc metalloenzyme, phospholipase C , and binds tomembranes in the presence of calcium.
We have solved the 3D-structure of a-toxin, in two different conformations: aclosed and an open form . Re·c ently we have also determined the 3D-structure ofthis toxin in presence of Ca2+ at pH4 .7 and 6.8 in order to address its mode offunction. The structure is composed of two domains: an N-terminal domain
made of a nine-helix bundle and a C-terminal domain, which is an anti parallelbeta sandwich.
The opening and closing of its active site and its implication towards its
mechanism of function with the cell membrane will be discussed .
Email: a.basak@mail.cryst.bbk.ac.uk

A6-3

CRYSTAL .STRUCTURE OF A RIBOSOME INACTIVATING VISCUMIN FROMINDIAN VISCUMIN ALBUM AT 2.8A. RESOLUTION

Vandana Mishraab, Ashok K. Varmaa, Savita Yadava, R.S.Sharmac, C.R.Babubc,
and T .P.Singha, aDepartment of Biophysics, All India Institute of Medical Sciences,
New Delhi-llO 029,lndia. bDepartment of Botany, University of Delhi, Delhi llO
007 ,India. ccentre for Environment Management of Degraded Ecosystems,
University of Delhi, Delhi 110 007,India.
Many Plants produce Ribosome Inactivating Proteins(RIPs)-enzymes that act onribosomes in a highly specific way, thereby inhibiting protein synthesis. Some
RIPs can bind to and enter cells, making them among the most-toxic substances
known so far . The lectins from mistletoe belong, like ricin, abrin and modeccin to
the group of toxic lectins of A and B chains. The A chain is an enzyme whereas
the E chain is a lectin. The heterodimeric toxic viscumin was isolated from apartial-parasite obtained from Indian western Himalayas. The purified viscumin
was crystallised by hanging drop vapour diffusion method against the same buffer
containing 55% ammonium sulphate. The crystals belong to hexagonal spacegroup P6 5 22 with a = b = 109A and c = 309.4A. The structure has been
determined by molecular replacement method and is currently being refined. The
present R-factor is 23.2% for all data to 2.8 A resolutions . The overall protein foldis similar to ricin. It shows considerable sequence and structural differences withthe european viscumin. The root mean-square-devia tions (r.m.s) calculated for carbon atoms of european ML-1 and Indian viscumin show higher deviation for
the A chain and lower for the B chain. The highest deviations are found for the
residues on the surface . The association of A and B sub units is predominantly
hydrophobic in nature.
Email : che072s@yahoo.com

A6-4

INSIGHT TO STRUCTURAL SUBSITE RECOGNITION IN PLANT TlllOL
PROTEASE-INHIBITOR COMPLEXES: UNDERSTANDING 1HE BASIS OF
DIFFERENTIAL INHIBffiON AND 1HE ROLE OF WATER

Supama Bhattacharya, S. Ghosh, S. Chakraborty. B.P Mukhopadhayay and Asok
Banerjee* . Biophysics Department. Bose Institute. Calcutta 700054. India
This work represents an extensive MD simulation I water-dynamics studies on aseries of complexes of inhibitors leupeptin, E-64, E-64-C. ZPACK and homologous
plant cysteine proteases (actinidin, caricain, chymopapain, calotropin 01) of
papain family with a view to understand the various interactions, nature of waterbinding, factors influencing it and the structural basis of differential inhibition.
The tertiary structure of the enzyme-inhibitor complexes were built by visualinteractive modeling and were subjected to energy minimization followed bydynamic simulation of 120 ps in water environment. DASA study with andwithout the inhibitor revealed the contribution of potential subsite residues
involved in inhibition. Though the interaction involving main chain atoms arequite similar. critical inspection of the model complexes reveal some significant
differences in the side chain interactions in S 2 -P2 and S 3 -P3 pairs due toalteration in residues arising from sequence differences in the equivalent positionsof respective subsites leading to differential inhibition. The key finding of thepresent study is a conserved site of a water molecule near oxyanion hole of the
enzyme active site. which is found in all the modeled complexes as well as in theseveral solved crystal structures of papain family either native or complexed .
Conserved water molecules at the ligand binding sites of these homologous
proteins suggest the structural importance of the water, which could effectively
change the conventional definition on chemical geometry of inhibitor binding
domain by changing its shape thus affecting the complimentarity. Again. th ewater mediated recognition of inhibitor to enzyme subsites (P 11 ... H20 .... S 11 ) ofleupeptin acetyl oxygen in caricain and chymopapain may also be an additional
information, which could offer valuable insight to potent inhibitor design.
Email: ashoke@bic.boseinst.ernet.in, abbp l @yahoo.com

A6-5

RECEPTOR BASED DRUG DESIGN OF NSAIDS: A KNOWLEDGE BASED
MOLECUlARMODELLING
STUDY
OF
COX-1
WI1H
N-PHENYLDICHLOROACETANILIDE.

Asok K. Pal, S.Bhattacharya, A.K.Bera. S.Ghosh, S .Chakraborty and Asok
Banerjee*.
Apart from their extensive chemical significance, the anti-inflammatory and anti
pyretic activities of acetanilide group of compounds and their derivatives are well
documented (Goodman, L.S., & Gilman, A. gth edition, vall, 1991}. Non-steroidal
anti-inflammatory drugs (NSAID} are potent inhibitors of the synthesis of
prostaglandins. The pharmacological target of NSAIDs is Cyclooxygenase (COX.
also known as PGH synthase}, the enzyme responsible for forming prostaglandin
from arachidonic acid. Prostaglandins are potent mediators for causing
hyperanalgesia associated with inflammation and pyretic response. To select andscreen out prospective candidates with appropriate stereochemical geometry as
potent drug with low toxicity for the suppression of elevated level of inflammationand fever, synthesis and crystal structure determination of N-phenyl
dichloroacetanilide (C 8 H 7 NOC1 2 } was done previously (Pal et a1 .. 1998}. A close
inspection of binding site and molecular recognition in a number of reported
structures for complex of cyclooxygenase with different structural classes of
NSAIDs (Picot et al., 1994; Loll et al., 1995; Loll et al. , 1996} has enabled us to
identify the key residues of the enzyme and a possible binding mode of acetanilidewith COX-1 . Difficulties associated with membrane protein crystallization have
prevented us from obtaining strongly diffracting crystals of COX-aceta nilide
complex till now and motivated us to build computer aided knowledge basedmodel of the complex to understand structure function relationship of therecognition when crystallization trials are being performed simultaneously. The
three dimensional model structure of cox-acetanilide complex may be useful as aprobe for solving the crystal structure of the same protein-inhibitor complex andadditionally it serves as a structural reference for protein engineering experiments
aimed at redesigning the functional properties of bio-active acetanilide.
Email: ashoke@boseinst.emet.in, abbp1@yahoo.com

A6-6
REFINEMENT OF 1WO STRUC1URES OF 1HE Yl74F MUTANT OF MNSUPEROXIDE DISMUTASE AT ATOMIC RESOLUTION (0.9 A).

Bryan F . Andersona.
Ross A. Edwardsa.
Mei M. Whittakerb, James W.
Whittakerb, Edward N. Baker<: and Geoffrey B. Jamesona. acentre for Structural
Biology, College of Sciences, Massey University, Palrnerston North, New Zealand.
bDepartment of Biochemistry and Molecular Biology, Oregon Graduate Institute,
Beaverton, Oregon, USA. cschool of Biological Sciences, University of Auckland,
Auckland, New Zealand.
Aerobic and many anaerobic organisms contain superoxide dismutases (SODs)
that remove 0 2 -· through a cycle that alternately reduces and oxidises a metal
centre:SOD-Mn3 + + 0 2 -·==> SOD-Mn2 + + 0 2
2
SOD-Mn + + 0 2 -· + 2H+ ==> SOD-Mn3 + + H 2 0 220z-· + 2H+ ==> Oz + HzOz
We have refined the structures of the Yl74F mutant of Mn-SOD from Escherichia
coli at 0 .9 A resolution. The structures are isomorphous and each comprises a
non-crystallographic dimer of -3470 protein atoms, 2 Mn atoms and -880 solvent
molecules. All non-hydrogen atoms have been refined with anisotropic thermal
parameters and the final cycles of refinement have included all protons attached
to non-ionisable protein atoms positioned by calculation. Many of the remaininghydrogen atoms were evident in the resultant difference maps. For wild-type
MnSOD-Yl74F, R 1 (observed data)= 0 .099.
Email : B.F.Anderson@massey.ac .nz

A6-7

CRYSTAL STRUCIDRES OF HUMAN DEOXY AND OXY HAEMOGLOBIN AT
DIFFERENT LEVELS OF HUMIDI'IY

B. K. Biswal and M. Vijayan, Molecular Biophysics Unit, Indian Institute of
Science, Bangalore 560 012 , India.
We have been exploring protein hydration and its consequences using anapproach involving water-mediated transformations in which protein crystals
undergo reversible transformations with change in solvent content whenenvironmental humidity is systematically varied. Using this approach it has beenpossible to establish a relation among hydration, mobility and action in lysozyme
and ribonuclease A. The more complex, but equally well studied, multimeric
protein haemoglobin is now being examined . Exploratory studies involving thesolvent content of met horse haemoglobin have indeed been conducted during theinfancy of protein crystallography. Following a well-laid strategy, the structures ofhuman oxy haemoglobin have been analyzed at relative humidities of 93, 90, 88
and 84%. Also analyzed is a crystal partially dehydrated in an environment of
25% methanol. The corresponding deoxy form was studied at 90% relative
humidity. The native structures, assumed to correspond to close to 100%
humidity, of both the forms are already available. The oxy form does not exhibit
any transformation while the deoxy form does. The low humidity form of the latterhas two crystallographically independent molecules instead of one in the native
crystals. The two molecules exhibit subtle and interesting differences in theirrelation to the liganded molecule.
Email : bichitra@mbu.iisc.emet.in

A6-8
lllGH RESOLUTION CRYSTAL STRUCTIJREINTERACTING FACTOR B (Cm)

OF

HUMAN

CCG 1/TAFll250-

B.Padmanabhan 1 , Takashi Kuzuhara2 and Masami Horikoshil. 2. 1 Horikoshi Gene
Selector Project. ERATO-Japan Science and Technology Corporation (JST). 5 -9-6
Tokodai, Tsukuba, Ibaraki 300-2635, Japan. 2Laboratory of Developmental
Biology, Institute of Molecular and Cellular Biosciences, The University of Tokyo.
l - l - 1 Yayoi, Bunkyo-ku. Tokyo 110-0032. Japan.
Transcription factor TFIID is a multi-protein complex composed of the TATA boxbinding protein (TBP) and its associated factors (TAFs). and is required for
accurate and regulated initiation of transcription by RNA polymerase II. The
largest subunit of TFIID . CCG l, which serves a central architectural role in theassembly of TFIID has the histone acetyltransferase (HAT) activity. To investigate
the functional regulation of CCG l HAT domain, we screened some interacting
factors with this domain using a yeast two-hybrid system. In this search, we haveobtained the eDNA of a novel factor CIB (CCG !-interacting factor B). As the role
CIB protein in the cell is not clearly known, we have initiated crystallographic,
biochemical and genetic studies on this protein.
The CIB protein crystals were grown in l.4-l.5M ammonium sulfate, l5mm urea,
70mM Tris-Cl, pH7.5, using hanging drop vapor diffusion method. Thin plate-likecrystals in the orthorhombic space group P2 12 1 2 with one molecule in theasymmetric unit, with cell dimensions of a= 110.70, b=44.45, c=43.60 A,
appeared in one week. A complete data set was collected to a maximum resolutionof l.7A, using the beam-line BLl8B at the synchrotron facility, Photon Factory,
Tsukuba. The structure was solved by MIR method using SOLVE package and therefinement was carried out using CNS. The present R-factor and R-free is 17.5% &22.0%, respectively at l. 7 A resolution. Surprisingly, the overall tertiary structureof CIB protein is similar to that of a./~-hydrolases . Details of the structure andfunction of the protein will be discussed.
Email : paddy@hgsp.jst.go.jp

A6-9

CRYSTAL S'IRUCTIJRE OF M. tuberculosis CHAPERONIN-10

Bhupesh Taneja and Shekhar C. Mande. Institute of Microbial Technology, Sector
39-A, Chandigarh-160036. INDIA.
Chaperonin-60 and chaperonin-10 are homologues of the well-characterized
GroEL and GroES molecular chaperones of Escherichia coli. Chaperonin-10 or
GroES acts as an allosteric modulator of chaperonin-60 (GroEL) by interactions
through its flexible 17 -residue mobile loop. The chaperonin- 10 of M. tuberculosis(Mt-cpn 10) also acts as an important T-cell antigen during infection. The crystal
structure of Mt-cpn10 has now been solved. c-centered orthorhombic crystals
were obtained with unit cell dimensions (A) of a=77.5, b=62.5 and c=125.6. The
structure was solved by molecular replacement using the main chain coordinatesof M. leprae heptamer using the Amore package of CCP4. The overall structure is
a 4-stranded ~-barrel with two long stretches of highly flexible segments, thedome loop and the mobile loop. The seven subunits in a heptamer have very little
conformational differences and exhibit nearly perfect 7 -fold geometry. Due to theflexibility of the mobile loop, its visualization has not been possible in the standalone structures of chaperonin-10 homologues solved thus far. Our structure
identifies a partially-stable conformation of the mobile loop. Binding sites form eta l ions in the dome loop have also been identified that have recently beenshown to modulate the plastic states of Mt-cpn10.
Email: bhupesh@imtech.res.in

A6-10X-RAY STIJDIES OF 1E1HERED lfiV-1 PRO'IEASE MUTANT AND INHIBITORCOMPLEXES

B. Pillai, S.V.Bhat 1 , 2N. Hariprasad, 2V. M. Kulkarni, K. K. Kannan & M. V.
Hosur*. SSPD, BARC, 1IIT-Bombay, 2UDCT, Mumbai.

HN (Human immunodeficiency virus), which is the causative agent for thecondition known as AIDS (Acquired immunodeficiency syndrome), encodes its
own protease enzyme, HN- PR which is absolutely essential for formation of
infectious virions. The residue at position 95 has been conserved across manydifferent strains of the virus, evnthough this residue is not part of the active site.
Inhibitors of HN-PR have been critical components of the HAART therapy for
AIDS. The emergence of drug-resistant virus necessitates design of very many
chemically different types of protease inhibitors through the process of structurebased drug-design.
We report here the 1.9A structure of the tethered HIV PR carrying a mutation
C95M in one of the subunits. Single crystals of size 0 .3x0.1x0.1mm3 were grownby the hanging drop vapour diffusion method. X-ray diffraction data to wascollected on a RAXIS IIC imaging plate detector system. The cry~tals belonged tothe hexagonal space group P6 1 with cell dimensions a=b=63.15A & c=83.6A andgamma =120°. The structure was solved using the molecular replacement
method. The major structure highlight is the closed conformation of the flaps ascompared to the open conformation of flaps seen in all the earlier studies on theunliganded enzyme. Interestingly the overall conformation of the ligand freetethered enzyme reported here is unexpectedly similar to the ligand boundenzyme rather than to the ligand free wild type enzyme. The environment aroundM95 and C1095 are identical showing no drastic structural effect of this mutation
at position 95.
X-ray crystallography has contributed immensely to drug development using theapproach of structure based drug design. In an attempt at rational drug design,
X-ray diffraction data was collected on crystals of HIV-1 PR soaked in solution of alead compound, designed using computer docking. The structure of the complex
was solved by the molecular replacement method. The inhibitor was located in the
difference electron density maps contoured at 2 sigma. Possible modifications in
the lead compound which could improve the potency of this compound will be
discussed.
Email : bindup@apsara.barc.emet.in

A6-11S'IRUC'IlJRAL CHARACTERIZATION OF INTERACTIONS FORMED BY IMPORTINa. DURING NUCLEAR IMPORT

B. Kobea, M.R.M. Fontesb, B. Catimelc, T. Tehb, E.C. Nicec, and D.A. Jansd,
anepartment of Biochemistry and Molecular Biology j Institute for Molecular
Bioscience, University of Queensland, St. Lucia 4072; bSt. Vincent's Institute ofMedical Research, Fitzroy 3065; cLudwig Institute for Cancer Research, Royal
Melbourne Hospital, Parkville 3050; dJohn Curtin School of Medic:il Research,
Australian National University, Canberra 2601, Australia.
Nuclear proteins are synthesized in the cytoplasm and need to be imported into
the nucleus through the nuclear pore complexes. Such import is directed by
special signals; the most common is the classical nuclear localization sequence ·(NLS). consisting of one (monopartite NLS) or two (bipartite NLS) clusters of basic
residues. The receptor that recognizes NLSs is the importin heterodimer;
importin-a. contains the NLS binding site, and importin-~ is responsible for theactual translocation through the pore.
To determine the structural basis of interactions formed by importin-a. during
nuclear import, we crystallized importin-a. and its complexes with peptides
corresponding to monopartite, bipartite and phosphorylation-regulated NLSs, andcomplemented the structures using a variety of biophysical techniques (biosensor,
ELISA. analytical centrifugation). Jointly, our results yield the following account ofrecognition events during nuclear import.
Importin-a. exists in an autoinhibited state and has a low affinity for NLScontaining proteins. The affinity for NLSs is increased through the association of
its autoinhibitory domain with importin-~. Importin-a. elegantly uses its
superhelical structure (armadillo repeats) to bind both the NLSs and theautoinhibitory region; the spacing of the armadillo structural units iscommensurate with the spacing of amino acids in the peptide .
Email: kobe@biosci.uq.edu.au

A6-12

STRUCTURAL STUDIES OF FOUR INACTIVE MUTANTS OF PENICILLIN V
ACYLASE FROM Bacillus sphaericus

Manish Chandraa. Jim Branniganb, Asmita Prabhunea. Archana Pundlea, Johan
Turkenburgb, Guy Dodsonb and C. G. Suresha. aDivision of Biochemical Sciences,
National Chemical Laboratory, Pune-411008, India. hChemistry Department,
University of York, York-YOlO 5DD , U.K.
Two types of Penicillin acylases, one specific for penicillin V and the other for
penicillin G, account for all the enzymatic production of 6 -arninopenicillanic acid
(6-APA), the key intermediate in the preparation of semi-synthetic penicillins. We
have been studying the structure activity relationship of penicillin V acylase (PVA)
from Bacillus sphaericus. The structure of PVA was solveded in hexagonal andtriclinic crystal forms. The structural comparison of PVA with penicillin G acylase(PGA) has shown that PVA like PGA belonged to the Ntn (N-terminal nucleophile)hydrolase family, and helped in the identification of the active site of the enzyme.
Based on information from structure comparison, selective mutants of PVA devoidof acylase activity could be prepared through site-directed mutagenesis. In orderto understand the catalytic mechanism and specificity of the enzyme, theformation of crystal complex of the mutants with penicillin V has been tried.
Specific mutants were prepared for probing into the mechanism of auto-catalytic
processing that results in the active enzyme. Crystal structures of four mutants(lCysAla. lCysGly, 175AsnAla and 228ArgSer) have been studied at various
resolutions. The first two mutants lacked the precursor peptide at theN-terminus ,whereas the second two had the precursor tri-peptide included in the clone. The
crystal structures of the latter two mutants showed that they underwent posttranslational processing. slower compared to native precursor, to change to theactive form . Details of the mutant structures in comparison with the structure of
the active form of PVA will be discussed.
Email : suresh@ems.ncl.res.inA6- 13

CRYSTAL STRU~TIJRE OF MACROMOLECUlAR ANTIBIOTIC Apo-Cl027 ANDCOMPU1ER MODELING ANALYSIS OF Cl027 CHROMOPHORE PR01EINCOMPLEX

Chen Y.. 1 Li J .,2 Bartlam M., 1 Gao Y. , 1 Ding Y. , 1 Liu Y. , 1Jin L. ,2 Tang H., lShao
Y., 2 Zhen Y .2& Rao Z. 1 !Laboratory of Structural Biology & Protein Sciences
Laboratory of MOE, School of Life Science and Engineering, Tsinghua University,
Beijing 100084, P.R.China. 2Institute of Medicinal Biotechnology. Chinese
Academic of medicine Science, Beijing, 100084. P.R. China.
C l 027 isolated from the culture filtrates of streptomyces globispourus C-1 0 27
(Wuhan, China). is a member of the macromolecular enediynes antitumor
antib iotic, which also include s actinoxanthin (AXN). neocarzinostatin (NCS).
auromomycin (AUR) and kedarcidin.
The three-dimensional structure of Cl027 is req1,1ired in order to deduce thefactors that determine the stabilization of the ch romophore by the apoprotein andto design stable analogues of the chromophore. By far, only one chromophoreapoprotein complex of NCS has been solved , while there is no information about
the chromophore-apoprotein complex of Cl027 being reported. Herein, we
reported the 1.8 Anstrgom resolution apo-Cl027 crystal structure . The protein
crystallized in space group p3l, with two molecules in the asymmetric unit and asolvent content of - 54%. The two structures in the asymmetric unit are very
similar, significant differences being limited to the orientation of some of thesurface side chains involved in crystallographic contact. The final Rwork and Rrree
were reduced to 18.5% and 23.7% respectively. The final model sta tistics for our
Cl027 structure were 0.014 A for bond length and 1.726 for bond angles. The
overall apo -Cl027 molecule consists primarily of /3 -sheets organized into two
domains, separated by a deep cleft which is the putative chromophore bindingsite . The large doma in forms a seven-stranded antiparallel /3-barrel that contains
two sheets: an external sheet consisting of strands 1,2 and 5 (residues4 to8, 19
to24. and 62 to 66 respectively) and an internal sheet formed by strands 4, 3, 6,
and 7 (residues 5 3 to 57, 30 to 35, 94 to 98 , and 108 to 110, respectively) . The
smaller domain consists of two twisted , two-stranded , anti parallel /3-sheets formed
by strand 3a and 3b(residues 36 to 40, and 44 to 48 , respectively) and strand 5aand 5b (residues 72 to 75 , and 84 to 87 , respectively) .
Although the chromophore wa s included during crystallization , there is no strong
electron d ensity in the final model, suggesting that the chromophore is released
from the a poprotein or is highly flexible and disorder. Ba sed on the apoprotein
structure, a modeling s tudy of the Cl027-Chr a nd Apo-Cl027 complex bycalculating va n der Waals and electrosta tic potential energies to explore thebinding site of the chromophore and how the apoprotein stabilize d th echromophore by the specific interaction tha t are unique to this complex.
Email : chenyh98@m a ils .tsinghua.edu. cn

A6-14

CRYSTALLIZATION AND PRELIMINARY X-RAY
ISOFORM ll FROM EQUISETUM ARVENSE

STUDY

OF

FERREDOXIN

Daisuke Nishiyamaa, Genji Kurisua, Masami K.usunokia, Toshiharu Haseb and
Keizo Teshimab , aResearch Center for Structural Biology, bOivision of Enzymology,
Institute for Protein Research, Osaka University, Suita. Osaka 565-0871, Japan.
and cFaculty of Integrated Arts and Sciences, Hiroshima University,
Higashihiroshima, Hiroshima 724, Japan.
Ferredoxin (Fd) is an iron-sulfur protein with a molecular weight of 11 kDa. Fds
containing the [2Fe-2S] cluster are distributed in photosynthetic organisms andcalled 'plant-type Fd'. It takes part in the photosynthetic electron transport chain
and plays an important role of assimilatory reduction. In higher plants , there areseveral Fd isoforms. which are genetically and structurally distinct from eachother. Leaves of field horsetail (Equisetum arvense) have two isoforms (Fd I andFdii). Fd I was characterized and crystallized as a representative of plant-type Fd .
Its 30 structure was already solved (S.Ikemizu et al., 1994) and structures
around the [2Fe-2S] cluster were highly conserved. According to comparison ofamino acid sequences of these two isforms, Fd II has appeared to have no arginine
residue around the [2Fe-2S] cluster conserved among the other Fds. This Arg
residue was thought to be crucial to form the microenvironment of the cluster. In
order to elucidate how the active site of Fd II is stabilized without this Arg residue,
we started the crystallographic study of Fd II from E.arvense. Crystallization was
performed by the hanging drop vapor diffusion method at 4°C. Crystals of Fd II
appeared in one week, diffracted at least to 1.8 A resolution and belonged to thespace group of C2 . Here we report the preliminary crystallographic study aimed at
higher resolution structure analysis.
Email : nishiyama@protein.osaka-u.ac.jp

A6-15
STRUCIDRE OF THE INDUCED ANTIBACTERIAL PROTEIN FROM TASARSILKWORM, Antheroea myUtta: IMPUCATIONS TO MOLECULAR EVOLUTION

Deepti Jain*1 , Deepak T. Nair*, G. Jawahar Swaminathan*, E. G. Abraham, J .
Nagaraju§ and Dinakar M. Salunke*2. *National Institute of Immunology, New
Delhi 110 067 INDIA, Seribiotech Research Laboratory, Bangalore 560 086 INDIAand §Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500 076 INDIA.
1 These two authors have contributed equally
The repertoire of proteins and peptides over-expressed on bacterial infection in
insects provides the first line of defense and acts cumulatively against a wide
spectrum of pathogens defining the humoral immune response. The crystal
structure of one such antibacterial protein of immune origin, which was purified
from tasar silkworm (Antheraea mylitta) larvae after induction by E. coli infection,
has been determined. The core structure of this protein is similar to c-typelysozymes and a-lactalbumins. The catalytic residues are conserved with respect
to the chicken lysozyme. While the A. mylitta protein is functionally similar tochicken lysozyme unlike human a-lactalbumin, it is significantly different incertain structural features with respect to the other two proteins. Althoughphysiological origins of the tasar silkworm protein and chicken lysozyme aredifferent, the catalytic mechanism employed by them would probably be similar
with subtle differences in the specificity and level of activity. On the basis of thestructural comparisons between tasar silkWorm protein, chicken lysozyme andhuman a-lactalbumin it can be suggested that the conformational changes in a
protein are minimal during rapid evolution as compared to those in the normal
course of evolution.
Email : dtnair@yahoo.com

A6-16
X-RAY CRYSTALLOGRAPlllC STIJDIES OF CEPHALOSPORIN ACYLASE

Ding Yi 1 Jiang Weihong 2 Mao Xiang 2 He Hongzhen 1 Zhang Shuping 1 Tang Hong 1
Bartlam Mark 1 Ye Sheng 1 Jiang Fanl Liu Yiwei 1 Zhao Guoping 2 Rao Zihe 1 .
Laboratory of Structural Biology & Protein science Laboratory of MOE, School ofLife Sciences Engineering, Tsinghua University 1 , Beijing 100084, China. Shanghai
Institute of Plant Physiology, Chinese academy of Science 2 , Shanghai 20000 ,China.
Cephalosporin acylases are a group of enzymes that hydrolyze cephalosporin C(CPC) and/or glutaryl 7-aminocephalosporanic acid (GL-7-ACA) to produce 7aminocephalosporanic acid (7-ACA) . The acylase from Pseudomonas sp. strain
130(CA-130)ishighlyactiveon
GL-7-ACA
andglutaryl
7aminodesacetoxycephalosporanic acid (GL-7 -ADCA), but showed low activity for
CPC. The detailed determination of the three-dimensional structure of thisenzyme, the research of the relationship between the structure and functions andthe site-directed mutagenesis for definite purpose will provide a new approachand a theoretical basis for improving the activity of this enzyme, so that an
improved strain of cephalosporin acylase which is more stable and high-expressed
is able to be obtained, the industrialization of producing cephem antibiotics withthe enzyme can be realized.
CA- 130 was crystallized in three different forms, two of which are suitable forstructural studies. A tetragonal crystal form diffracted to 2.4 A and belongs to thespace group P4 1 2 1 2, with unit-cell parameters a=b=73.5A, c=382.0A. It is giventhat there is one a~ heterodimer per asymmetric unit. A second crystal form
diffracted to 2.1 A and belongs to the space group P2 1 , with unit-cell parameters
a=l30 .6 A, b=108.6 A, c=135.5 A, ~=116.0° . It is given that there are four a~heterodimers per asymmetric unit. The tetragonal crystal structure of CA-130 was
determined by MAD m ethod , and the P2 1 crystal structure was then determinedby Molecular Replacement method. The structure determination of th e protein
complex with some different substrates is being carried on, which may
demonstrate the activation mechanism of this enzyme more deeply. Besides native
protein, we have done a lot of work on cloning, expression, purification andcrystallization of inactive mutant protein. Furthermore , we will try to soak the
crystals in the substrates and also co-crystallize the inactive protein with thesubstrates .

A6-17ENHANCED BINDING OF A RATIONALLY DESIGNED PEPTIDE UGAND OF
CONCANAVALIN
A
ARISESFROMIMPROVEDGEOMETRICALCOMPLEMENTARTIY

Deepti Jain, Kanwal J . Kaur and Dinakar M. Salunke. Structural Biology Unit,
National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
The structural basis of affinity enhancement was addressed by analyzing theinteractions between concanavalin A and the carbohydrate-mimicking peptide
ligands. Based on the crystal structures of concanavalin A in complex with these
peptides [Jain et al. (2000) J. Biol. Chern. 275,16098-16102; Jain, et al. (2001)
Biophys. J. 80:2912-2921], a high affinity analog was designed. This analog(Acetyl-MYWYPY-amide) binds to the lectin with 32-fold enhanced affinity
compared to the corresponding precursor peptides. Crystal structure ofconcanavalin A bound to the designed peptide has been determined . A peptide
molecule binds to each of the crystallographically independent monomers of thetetrameric lectin. The four bound peptide molecules exhibit two major
conformations both of which are extended. Unlike in the case of otherconcanavalin A binding peptides, the structural variations within different
conformers of this analog are marginal. It is apparent that the deletion of thestructurally variable region of the larger peptides has led to an improved
complementarity and increased buried surface area in case of the designed
peptide. The crystal structure also showed formation of two backbone hydrogenbonds between the ligand and the ligate which were not present in the complexesof the precursor peptides. The observed structural features adequately explain theenhanced binding of the designed analog.
·
Email : dinakar@nii.res.in

A6-18CRYSTAL STRUC1URE OF AMINOGLYCOSIDE (31 PHOSPHOTRANSFERASE-ll,
AN EN:lYME IMPI.JCA'IED IN ANTIBIOTIC RESISTANCE

Steven C. Shewry 1 , Didier Nurizzol, Michael H. Perlin2, Clyde A. Smith 1and
Edward N. Baker 1 , 1School of Biological Sciences, University of Auckland ,Auckland, New Zealand, and 2Department of Biology, University of Louisville, KY.
The largest class of clinically relevant antibiotics, apart from the ~ - lactams,
function by inhibiting protein synthesis. Amongst these are aminoglycosideantibiotics, such as kanamycin and tobramycin, which kill bacteria by binding to
the 30S ribosomal subunit. Resistance to such antibiotics is mediated byenzymes that chemically modify the antibiotics by transferring nucleotide. acetylor phosphoryl groups onto specific positions on the drug. As part of a program toinvestigate the molecular basis of aminoglycoside resistance, we have determined
the structure of aminoglycoside 3'-phosphotransferase-II [APH(3') -II). We havecrystallized APH (3')-II in the presence of kanamycin, and solved and refined thestructure at 2 . 1-A resolution. APH (3')-II has a two-domain fold very similar to theprotein kinases, with a deep cleft where the kanamycin molecule is bound.
Kanamycin binds through a large number of hydrogen bonds to conserved
residues in the protein. The ATP-binding site is occupied by a sulfate ion . The
structure shows evidence of some flexibility around the active site cleft that may
be related to its different substrate specificity. This involves a small loop and an
a-helical bundle subdomain. The structural differences between this family of
enzymes and the protein kinases will be presented.
Email: ted.baker@auckland .ac.nz

A6-19STRUCTIJRE OF A NOVEL ALCOHOL DEHYDROGENASE SOLVED BY MADPHASING FROM A SINGLE COBALT ATOM

Heather M. Bakera. Andrew A. McCarthya. Geoffrey B. Jamesonb and Edward N.
Bakera, aschool of Biological Sciences. University of Auckland. Auckland. New
Zealand, and bJnstitute of Fundamental Sciences, Massey University, Palmerston
North, New Zealand.
Alcohol dehydrogenases (ADHs) are ubiquitous throughout all living species,
because of the common use of alcohols as substrates in metabolic pathways.
Structures are well known for several families of ADHs but other, apparently
unrelated, ADHs exist. We have determined the 30 structure of an irondependent ADH from the bacterium Zymomonas mobilis (zADH). which has nosequence identity with any protein in the Protein Data Bank, but which is related
to a much wider family of dehydrogenases. The structure of this 40 kDa enzyme
has been solved by MAD phasing from a single Co 2 + ion, substituted for Fe 2 +.
Remarkably, despite no sequence identity, the protein proves to be structurally
homologous with the Zn-dependent enzyme dehydroquinate synthase (DHQS).
which catalyses the second step of the shikimate pathway for aromatic amino acidbiosynthesis. Both perform an alcohol oxidation, and both have similar metal andNAD(H) binding sites. albeit with different metal specificity. The zADH enzyme
has also been used in random mutagenesis studies that allow us to pinpoint sites
in the structure that alter metal. cofactor and substrate specificity.
Email: ted.baker@auckland.ac.nz

A6-20CRYSTAL STRUCIDRE OF PEA TOC34: A GTP-ASE IRANSWCON AT 1HE
OUTER MEMBRANE OF ~HLOROPLAST

F. Forouhara, Y.-J. Suna.b, H.-M. Lia, C.-C. Choua and C.-D. Hsiaoa alnstitute of
Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan hDepartment ofLife Science, National Tsing Hau University, Hsinchu, Taiwan.
Toc34, a 34-kDa integral membrane protein, is a member of the Toe (iranslocon
at the Quter envelope membrane of .c;:hloroplast) complex that associates withprecursor proteins during protein transport across the chloroplast outermembrane. Toc34 is composed of an N-terminal cytosolic 29-kDa GTP-binding
domain, a single transmembrane domain and a 3-kDa C- tail exposed to theintermembrane space. Toc34 is postulated to be involved in modulating thegating property of the main channel of the Toe complex, Toc75, or in recognitionand presentation of the precursors . Here, we report the crystal structure of thecytosolic part of pea Toc34 in complex with GDP and Mg2+ at 2.0 A resolution.
The crystal structure of Toc34 reveals unique features that have not been
observed in other GTPases reported to date.
Email : farhadf@gate .sinica.edu. tw

A6-21

SOFIDOCK UNDERSTANDING OF MOLECULAR RECOGNmON TIIROUGHSYSTEMATICALLY DOCKING S1UDY

Fan Jiang. Wei Lin, and Zihe Rao. Department of Biological Sciences andBiotechnology, Laboratory of Protein Sciences MOE, Tsinghua University, Beijing
100084, P.R.China.

Keywords: Interface packing/Molecular
dock/Systematic docking.

complex/Molecular

recognition/Soft

Molecular recognition and docking is essential to the biological functions ofproteins. SOFTDOCK was one of the first molecular docking methods developed
for protein-protein docking. Its ability to represent the molecular surface withdifferent shapes and properties and to dock a variety of molecular complexes withcertain conformational changes has been demonstrated in the previous study. In
the present work, we study the effects of the docking parameters throughstatistical analysis. Seventy one typical binary complexes of different categories in
PDB were also systematically docked for a test. 57 of them produced correct
solutions with one set of docking parameters while the other 14 complexes
required adjusting the docking parameters. by decreasing the softness of therecognition and hence the background noise. We found that these 14 complexes
had special structural features . Our results suggest that a variety of mechanisms
may be involved in molecular recognition rather than the shape complementarity
only, which is very helpful in developing more powerful methods in predicting
molecular recognition.
Email : jiangf@tsinghua.edu.cn

A6-22ANALYSIS OF CATALYTIC MECHANISM OF ,8-AMYLASE FROM B.cereus var.
mycoides BY X-RAY CRYSTAL STRUCIDRE OF CATALYTIC RESIDUE MUTANTS

H. Miyake a, C. Otsuka a , G. Kurisu b, M. Kusunoki b, S. Nishimura a andY. Nitta
a . aGraduate School of Agric . Biol. Sci., ·osaka Pref. Univ, 1-1 Gakuen-cho, Sakai,

Osaka 599-8531, JAPAN, and bJnst. Protein Res ., Osaka Univ, 3-2 Yamadaoka,
Suita, Osaka 565-0871, JAPANThe X-ray crystal structures of catalytic-site mutants E172A [Glu172 Ala] andE367A [Glu367 Ala] of ,8-amylase from Bacillus cereus var. mycoides in complex
with maltopentaose (G5} has been determined at 2 . 1A and l.95A resolution,
respectively. Restrained crystallographic refinement has resulted in R-factors of
18.0% and 19.2 % in the 40 .0 to 2.1A and 40 .0 to l.95A resolution ranges ,respectively. Clear and continuous density corresponding to a pentasaccharid e
was observed in the E172A crystal in complex with G5, consisting of Glc1 to Glc5
(Glc1 is the non-reducing end glucose residue of the substrate) . The conformationof the glucose residues of Glc2 and Glc3 shows a sharp turn without distortion of
the puckering of Glc2 . On other hand, each one molecule of glucose andmaltotetraose was observed in the active site cleft of the E367A crystal in complex
with G5. A carboxyl oxygen of Glu 172 forms a hydrogen bond with the glucosidic
oxygen in the scissile bond between Glc2 and Glc3 . This hydrogen-bond indicatesthe protonated state of Glu 172 in the initial kinetic complex between wild -type
enzyme and substrate. A water molecule located near the carboxyl oxygen of theother catalytic residues Glu367 may be activated by Glu367 . These results
indicate that Glu172 acts as a general acid and Glu367 as a general base.
Email : kurisu@protein .osaka-u.ac.jp

AB-23

CLONING, EXPRESSION, PURIFICATION AND
CHROMO SHADOW DOMAINCRYSTALLIZATION OF M31

Gao Y., Geng B., Shng N., DingY., Xu Y., Wang Z., Gao F., Tong H., He C., Rao Z.,
Laboratory of Structural Biology, Protein Science Laboratory of MOE, School ofLife Sciences Engineering, Tsinghua University, Beijing l00084,China Institute ofbasic medical sciences PUMC&CAMS
The heterochromatin protein 1 (HPl) family of proteins represents the bestcharacterized heterochromatin-associated nonhistone chromosomal protein family
in the eukaryotic kingdom. Its remarkable evolutionary conservation suggests a
fundamental role of HPl proteins in nuclear organization and a highly conserved
set of macromolecular interactions. They are composed of two related domains:
anN-terminal chromo domain and a C-terminal shadow chromo domain. In order
to investigate the role of the shadow chromo domain of murine HPl-like protein,
M31 , in heterochromatin formation using the structural biology method, we havesubcloned the CSD domain by PCR and ligated into the BamHI and XhoLI sites ofthe pGEX-4T-l vector. Plasmid was transformed into host strain BL21 (DE3).
After expression, protein was purified by GST chromatography and gel-filtration
chromatography. Hanging drop vapor diffusion method was used to research the
crystallization conditions. Crystals were obtained in about 7 days at l8°C undercertain conditions and a set of data has been collected at 115K.

A6-24

CRYSTAL S1RUCnJRES OF 1WO ISOFORMS OF KRAIT PI.A2S AS DIMERS AND
1RIMERS AT 2.1 AND 2.5 A RESOLUTIONS.

Garima Singh, Sujata Sharma, S.Gourinath, Pravinder Kumar and Tej .P.Singh.
Department of Biophysics, All India Institute of Medical Sciences, New Delhi-29 ,India.
Phospholipase A2 (PLA2s) enzymes hydrolyze phospholipids at sn-2 position of
the glycerol backbone, releasing lysophospholipids and fatty acids. The venoms ofmany poisonous animals contain a diverse cocktail of toxins, often neurotoxins,
conferring potency against a spectrum of targets and prey. The venom of krait
contains a-bungarotoxins, which block acetylcholine receptors on the presynaptic
membrane of neuromuscular junctions, and ~-bungarotoxins a completely
unrelated set of proteins. which inhibit neurotransmitter release from presynaptic
membrane. In addition to bungarotoxins, the venom of Indian common krait(Bungarus caeruleus), also contains a number of isoforms of free PLA2 enzymes.
Two new forms of krait PLA2s (KPLA2s) were isolated, crystallized and their threedimensional structures were determined. One isoform was crystallized as a dimer
while the other as a trimer. The crystals of dimer KPLA2 belong to rhombohedral
space group R3 with a=b=80.4 A, c= 57.9 A and the crystals of trimer weremonoclinic with space group C2 with a= 80.9 A b=80.6 A , c=57.1 A, ~= 90.3°.
The crystals of dimer diffracted to 2.1 A while those of trimer diffracted to 2.5 A.
The structure of dimeric and trimeric forms were refined to R-factors of 0.192 and
0.198 respectively. The structures of PLA2s in both forms are essentially similar.
However, the interactions at the interfaces of dimers and trimers are strikingly
different as altogether different amino acids participate in the interfacialinteractions. It may also be mentioned that the previously reported isoform
crystallized as a monomer. It appears that the different isoforms in KPLA2
aggregate differently to diversifY its strategy to attain a higher of lethality against
its prey.
Email : garimas@hotmail.com

A6-25MECHANISTIC IMPUCA110NS FROM TIIE STRUC'llJRES OF TIIE
MUTANT OF MN-SUPEROXIDE DISMUTASE AT 0.9 A RESOLUTION.

Y174F

Geoffrey B. Jamesona,Ross A. Edwardsa,
Mei M. Whittakerb, James W.
Whittakerb, Edward N. Bakerc and Bryan F. Andersona. acentre for Structural
Biology, College of Sciences, Massey University, Palmerston North, New Zealand.
bOepartment of Biochemistry and Molecular Biology, Oregon Graduate Institute,
Beaverton. Oregon, USA. cschool of Biological Sciences, University of Auckland,
Auckland, New Zealand.
The superoxide ion, o 2 -·, is a toxic byproduct of aerobic lifestyles. All aerobes andmany anaerobes contain superoxide dismutases that convert o 2 - · to dioxygen andhydrogen peroxide (for removal by catalase and peroxidases):
SOD-Mn3 + + 02-.
==> SOD-Mn2+ + 02
2
SOD-Mn + + 02-. + 2H+ ==> SOD-Mn 3 + + H20 2
202-. + 2H+ ==> 02 + H202
The structures of wild-type and reduced forms of the Yl74F mutant of Mn-SOD
from Escherichia coli at 0.9 A resolution provide unprecedented insight into theactive site, in particular into the location of hydrogen atoms in the vicinity of themetal centre. To our surprise, the solvent species coordinated to the Mn(II) centre
appears to be an hydroxide ion (not water), giving insight into the redox tuning
and metal specificity exhibited by members of the closely homologous family of
Fe- and MnSODs ..

Email : G.B.Jameson@massey.ac.nz

A6-26

RE-REFINED S'IRUCTURE OF GARLIC LECTIN. EFFECT OF BETIER DATAPROCESSING AND REFINEMENT

Gosu Ramachandraiah, N.R.Chandraa, A.Surolia, M.Vijayan . Molecular Biophysics
Unit and aBioinformatics Centre, Indian Institute of Science, Bangalore 560 012 ,India.
Garlic lectin is a dimeric protein, specific to mannose, belonging to the bulb
family. Its structure, reported earlier (Chandra, N.R., Ramachandraiah, G.,
Bachhawat, K., Dam, T.K., Surolia. A. and Vijayan, M. J Mol Biol. 285, 11571168 (1999)), among other things, indicated the possibility of oligomerisation as a
strategy for generating carbohydrate specificity. However, there were ambiguities
in details such as the identification of the correct isolectin, presumably on
account of the poor quality of the data. Better quality crystals could not be grownin spite of repeated efforts. Therefore, the same data were reprocessed using
DENZO. The structure was refined using newly processed data employing XPLOR and CNS. For comparison, the old data set in conjunction with CNS wasused to produce another coordinate set in addition to the original data set
obtained using X-PLOR. Thus the effort resulted in four sets of refinedcoordinates which enabled a comparative study of the two processing andrefinement programs. The combination of DENZO and CNS produced the best
results. The quality and the resolution of the map and the definition of thestructure improved substantially. In particular, the amino acid residues at thevariable locations in the sequence, and hence the isolectin, could be identified
with a high degree of confidence. It could be established that the crystal
asymmetric unit contains two identical hetero-dimers.
Email : gosu@mbu.iisc.ernet.in

A6-27

X-RAY CRYSTAL STRUCWRE OF A METHYLTRANSFERASE (Rv2118c) FROM
Mycobacterium tuberculosis H37Rv IN COMPLEX WI1H S-ADENOSYL LMETHIONINE.

Arnrita Gupta 3 • P. Hart Kumara, T.K. Dineshkumarb. Umesh Varshneyb andHosahalli S. Subramanyaa. 3 Molecular and Structural Biology Division, Central
Drug Research Institute, Chattar Manzil Palace, Mahatma Gandhi Marg. P.B. No.
173, Lucknow 226001, India. bDepartment of Microbiology and Cell Biology ,Indian Institute of Science. Bangalore 560012, India
The Rv2ll8c is a 30kDa protein, belonging to the class of conserved hypotheticals
from M.tuberculosis H37Rv. High resolution structure of Rv2ll8c, determined by
MIR method, revealed that it is a S-Adenosyl L-methionine (Ado-Met) dependent
methyltransferase. The crystallographic asymmetric unit consists of a monomer.
The quatemary organization of the protein is a tetramer. Due to extensive dimericinteractions, it could be described as a dimer of tight dimers. This quaternaryarrangement is consistent with the gel filtration experiments where the protein
elutes at a tetrameric position.
The monomer can be functionally divided into two domains. The larger catalytic
C-terminal domain is primarily a mixed a/~ structure with modified Rossman fold .
It is very similar to other Ado-Met dependent methyltransferases. The smaller Nterminal domain consists of ~-hairpin motifs and has a unique fold not found inother methyltransferases of known structure. The N-terminal domain packs
against the C-terminal domain contributing significantly to subunit interactions .
The cleft between the two domains is probably significant in substrate recognition
and binding.
Structure comparison and multiple sequence alignment studies indicate thatthree of the motifs reported to be highly conserved in diverse Ado-Met MTases area lso present in Rv2118c. Database searches reveal significant sequence homology
to several conserved hypothetical proteins particularly from Archae andEubacteria. Some of these sequences have been classified as homologues ofProtein Isoaspartyl Methyltransferase (PIMT). However sequence and structural
studies indicate that they have a different functional role or at least represent a
different class of PIMT. Comparison of catalytic domain of Rv2118c based on
structural alignment with the corresponding domains from well-characterized
Ado-Met Mtases indicated that Rv2118c might be closer in structure to RNA andsmall molecule MTases . Also structural analysis, homology to yeast Gcdl4p andlimited docking studies using tRNA substrate suggest that Rv2118c could be an
RNA methyltransferase but further studies are required to conclusively prove its
functional role.
Email: subshs@rediffmail.com

A6-28
AL1ERNATE CONFORMATIONS FOUND IN CATALYTIC SERINE OF Bacillus
sub tills LIPASE DE1ERMINED AT 1.3A RESOLUTION

Hidemasa Kondoa, Kosei Kawasakia, Mamoru Suzukib, Satoru Ohgiyaa and Sakae
Tsudaa, aNational Institute of Advanced Industrial Science and Technology (AIST).
2-17-2-1 Tsukisamu-Higashi, Toyohira. Sapporo 062-8517, Japan, and bPhoton
Factory, Institute of Materials Structure Science (IMSS). High Energy Accelerator
Research Organization (KEK). 1-1 Oho, Tsukuba, Ibaraki-ken 305-0801. Japan.
Bacillus subtilis extracellular lipase (BsL) has exceptionally small molecularweight (19.4kDa) in lipase family. BsL should be a potential enzyme for industrial
purposes because of its enzymatic property. We started crystallographic study on
BsL in order to design mutant BsL suitable for an industrial enzyme based on thethree-dimensional structure. Recently, crystal structure of BsL was determined at
1.5A resolution (Van Pouderoyen et al. J. MoL BioL (2001) 309, 215-226). In thepresent study, we originally crystallized new crystal form of BsL, which gives
diffraction with higher resolution. and determined structure at 1.3A by MAD
method.

It was found that the active site Ser77 has alternate conformers in its side chain.
Oy atom of the first conformer makes hydrogen bond to Ne atom of His155. amember of catalytic triad. In contrast, the second conformer is stabilized byhydrogen bonds to a water molecule and side chain of adjacent His76. These two
conformers seem to be an active and an inactive state, respectively. Moreover, a
glycerol molecule, which was used as a cryoprotectant, is located in the activesite. From these observations. we constructed a substrate-binding model of BsL.
In the presentation. we will discuss about a mechanism of catalytic reaction.
Email : h.kondo@aist.go.jp

A6-29CRYSTALLOGRAPIDC STUDY OF A PlATELET-AGGREGATION INHIBITOR,TRIMESTATIN FROM SNAKE VENOM

Hiroshi Mizuno 1 , Yoshifumi Fujii 1 , Zui Fujirnoto 1 , Taiju Okuda2, and Takashi
Morita 2, 1 National Institute of Agrobiological Sciences, Tsukuba, lbaraki 3058602 , Japan , and 2Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588,
Japan
Disintegrins from snake venom are generally defined as low molecular weight (4984 amino acids), cysteine-rich, also containing Arg-Gly-Asp/Lys-Gly-Asp(RGD /KGD) tri-peptides that inhibit the binding of fibrinogen to integrin allb~3 onplatelet membranes, as well as the binding of other ligands, such as fibronectin,
vitronectin, collagen and von Willebrand factor, to integrins on the surface ofcells. Disintegrins have been described as being unique and potentially usefultools not only for investigating cell-matrix and cell-cell interactions but also fordeveloping various agents, such as antithrombotic, antimetastatic in terms of
their anti-adhesive property, anti-migration against certain tumor cells, andantiangiogenesis.
We have revealed the crystal structure of trirnestatin at 1. 7 A resolution using themolecular replacement methods from NMR structures . The final R-factor and Rrree
are 18.7 and 21. 7% , respectively. This is the first crystal structure of disintegrin,
and flexible region of RGD tri-peptides in the NMR structures are now clea rly
seen. This stationary information of RGD sequence may help the radical design ofanti-thrombosis drug such as (1) peptidyl .competetor (like eptifibatide) and (2)non-peptidyl competetor (lamifiban, tirofiban).
Email : mizuno@nias.affrc.go.jp

A6-30S'IRUCTURE AND CARBOHYDRATE SPECIFICITY OF ARTOCARPIN

J. Venkatesh Pratap, P. Geetha Rani, K. Sekar•. A. Surolia & M. Vijayan .
Molecular Biophysics Unit and *Bioinformatics Centre, Indian Institute of Science,
Bangalore- 560 012 INDIA.
Lectins are multivalent carbohydrate binding proteins that specifically recognize
diverse sugar structures and mediate a variety of biological processes . The seeds
of jack fruit (Artocarpus integrifolia) contain two lectins - jacalin and artocarpin .
Both lectins are tetrameric with similar molecular weight, but differ in theircarbohdyrate specificity. Jacalin is specific to galactose while artocarpin is
specific to mannose. The crystal structure of jacalin complexed with methyl-exgalactose was solved earlier in this laboratory. Two crystal fonns of artocarpin in
the saccharide-free state were obtained and diffraction data from them (up to 2.4
Al were collected. Partial sequence information available at that time indicatedthat this protein is similar to jacalin. The structure was solved using themolecular replacement method employing AMoRe, with the jacalin tetramer as thesearch model. The structures were refined using the available partial sequence
information, the electron density map and the sequence of jacalin. The sequenceof KM+, a lectin from South American jack fruit seeds and similar to artocarpin in
its biochemical properties, became available during the later stages and was also
used. The carbohydrate binding site can accommodate both galactose as well as
mannose. Energy minimisations were performed on artocarpin-mannose andartocarpin-galactose complexes. A similar study was undertaken on jacalin as
well. Interaction energy and buried surface area calculations of the minimised
systems favour the correct ligand in both the proteins. The major difference inthe carbohydrate binding region of the two proteins is the presence of aromatic
residues in jacalin and their absence in artocarpin. This absence of stacking
interaction could contribute to determining the sugar specificity of artocarpin.

Email : pratap@mbu.iisc.emet.in

A6-31
ROLE OF COUNTER MICELLAR STRUCTUREION OF THE SURFACTANT MOLECULE ON THE

J.V. Joshi 1 , V.K. Aswal2 , P.S. GoyaP and P. Bahadur3, lJUC-DAEF (2SSPD).
Bh abha Atomic Research Centre, Trombay, Mumbai - 400 085, 3Department of
Ch emistty . South Gujrath University, Surat- 395 007
Surfactant molecules (e.g. SDS). having dual affinity for water and oil, self
aggregate into supermolecular structures when dissolved in water or oil. The
s implest aggregate of these surfactant molecules is called a micelle. In general.
micelles could be spherical, cylindrical, ellipsoidal or disk like in shape.
In case of ionic surfactants. such as Sodium Dodecyl Sulphate (SDS).
[CH 3 (CH2 ) .. . . S04r Na+, The surfactant molecule ionizes in water and the micellela rge ly onsists of Dodecyl Sulphate (OS-) ions. The Na+ ions referred to as
counter ions. tend to stay near the surface of the micelle. To examine the effect of
the size and the charge of the counter ion on the micellar structure, we havecarried out Small Angle Neutron Scattering (SANS) experiments on LiDS, NaDS,
KDS. RbDS. Cu (DSh. Mg(DSh. Co(DSh. Ni(DSh, using the SANS diffractometerat Dhruva reactor. The data analysis was done using Hayter and Penfold model.
These stud ies show that micelles are ellipsoidal in above solution and a/b ratio ofth e C' lli pso id depends both on sizes and valencies of the counter ions. Details ofth e experiments, d a ta analysis and the results will be presented.
Email : iuc@ m agnum .b a rc.ernet.in

A6-32MECHANISM OF IRON-BINDING IN IACTOFERRINS: CRYSTAL STRUCTIJRE OF
AN IRON-SATIJRATED INTERMEDIATE IN 1HE Fe3 + BINDING PATHWAY OFCAMEL IACTOFERRIN AT 2. 7 A RESOLUTION.

Javed A. Khan, Pravindra Kumar, A. Srinivasan, and Tej P. Singh*.Department ofBiophysics, All India Institute of Medical Sciences, New Delhi 110029, India.
This is the first ever protein intermediate obtained in the crystalline state by thesimultaneous process of Fe3+ binding and crystal nucleation and is also the firststructure of an intermediate of lactoferrin in the Fe3+ binding pathway. Lactoferrin
is an iron binding 80 kDa glycoprotein. It binds Fe3+ very tightly in a closed interdomain cleft in both lobes. The iron-free structure of lactoferrin, on the other
hand, adopts an open conformation with domains moving widely apart. It implies
that initial Fe3+ binding must be in the open form . The protein intermediate wascrystallized by microdialysis method. The protein solution with a concentration of
100 mg/ml in 10 mM Tris-HCl pH 8.0 was loaded in a capillary and dialyzed
against the same buffer containing 26 % (v /v) ethanol placed in a reservoir. FeCl3
and C0 32 - in excess molar ratios to that of protein in its solution were added to
the reservoir buffer. The crystals appeared after some hours and grew to the
optimum size within 36 hours . The structure was determined by molecularreplacement method and refined to final Rand free-R factors of 0.187 and 0.255
respectively. The present structure showed that the protein molecule adopts anopen conformation similar to that of camel apolactoferrin. The electron density
map clearly indicated the presence of two iron atoms , one in each lobe with fourfold coordinations: two by the protein ligands of Tyr 92(433) OH and Tyr 192(526)OH, and two other coordination sites are occupied by oxygen atoms of bidentate
C0 3 2 - ions leading to a tetrahedral intermediate. The C0 32 - anion is stabilized
through hydrogen bonds with the synergistic anion-binding site Arg 121(463) andwith Ser 122 Oy in N-lobe and Thr 464 Oy in C-lobe. The third oxygen atom of
C0 32 - is interacting with a water molecule in both lobes.
Email : jakh@hotmail.com

A6-33

STUDIES ON A RECOMBINANT CHYMOTRYPSIN INHIBITOR PROTEIN AND 1WO
OF ITS MUTANTS

Jhimli Dasgupta, S . Ravichandran, Chandana Chakrabarti and J.K. Dattagupta.
Crystallography and Molecular Biology Division, Saha Institute of Nuclear
Physics , l I Af Bidhan nagar, Kolkata 700 064, India.
Based on an in depth analysis of the structural results available so far in the
Kunitz (Sti) family of Serine protease inhibitors , Protein Engineering was initiatedin our la boratory with an ultimate aim to alter the inhibitor specificity of wei, a 20
Kd Chymotrypsin inhibitor from Winged Bean Seeds, belonging to this family. The
protein was cloned for structural and biochemical studies and was subjected topoint mutations at a conserved position. Asnl4. This residue, known to have apivotal role in stabilizing the first reactive-site of the inhibitor, is highly conservedin the sequences of the other members of Kunitz (Sti) family. Crystallographic
studies with l .9 A Synchrotron Cryo Datasets for a recombinant wci(Rwci) , andtwo of its mutants (Nl4k and Nl4d) have been made. These studies on therecombinant and the mutant proteins are primarily aimed at understanding theimportance of the protein Scaffolding towards the conformational rigidity of thereactive-site loop. Results will be presented.
Email: JHIMLI@CMB2.SAHA.ERNET.IN

A6-34
CRYSTAL STRUCIDRE OF A HUMAN RHINOVIRUS 1YPE 14 (HRV14):HUMANIMMUNODEFICIENCY VIRUS 1YPE 1 (lllV-1) V3 WOP CmMERIC VIRUS TIIATELICITS A NEUTRALIZING ANTIBODY RESPONSE AGAINST lllV-1

Ding. J.1.2, Smith, A.D. 1, Geisler, S.C. 1, Arnold, G.F . 1. and Arnold . E . 1.1Cente r
for Advanced Biotechnology and Medicine (CABM) and Rutgers University
Chemistry Department, 679 Hoes Lane, Piscataway, NJ 08854-5638, USA
2Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of
Sciences, 320 Yue-Yang Road, Shanghai 200031, China.
The structure of a chimeric human rhinovirus type 14 (HRV14) that displays on
its surface an immunogenic insert from the gp120 V3 loop of the humanimmunodeficiency virus type 1 (HIV-1) has been solved at 2 .7 A resolution. The
virus, designated MN-III-2, was isolated from a combinatorial library by
immunoselecting with a variety of anti-HIV-1 V3 loop monoclonal antibodies. The
HIV-1MN V3 loop segment, IGPGRAFYTIKN, was flanked by 0-3 randomized
residues on each side and inserted between HRV14 viral protein 2 residues
Ala159 and Asn160, allowing for diverse presentation of the V3 loop segment(Smith et al., 1998. J. Virol. 72, 651-659). The V3 loop insert of MN-III-2 wasflanked at its N-terminus by a three-residue linker, ADT. This chimeric virus wasable to elicit the production of antisera in guinea pigs capable of neutralizing HIV1 (MN and AlA isolates) . Structure refinement of the current model has
converged to an R-factor of 21.6%. The overall structure of MN-III-2 is similar tothat of wild-type HRV14. The structure of the V3 loop insert is dominated by two
type-1 13 turns. The first type- I 13 tum consists of residues GRAF and the second ,residues TTKN. Comparisons with the previously reported structures of V3 loop
peptides in complexes with Fab fragments of three neutralizing antibodies revea lthat the V3 loop insert in the MN-III-2 chimeric virus adopts a conformation thatis somewhat different from those seen in the Fab/peptide complexes. The major
conformational difference is localized to the GR residues of the second 13 turn .
However, the GPG and the RAF residues in the chimeric virus can besuperimposed upon the corresponding segments in the Fab/peptide complexes.
The results suggest that the V3 loop has an inherent conformational flexibility
and can adopt multiple conformations. Thus, the relatively conserved GPGRAF
motif of the V3 loop appears to consist of two well defined structural modules that
can alter their relative conformations and orientations, resulting in distinct V3loop conformations and, possibly, functions .
Email : ding@sunm.shcnc.ac.cn , ding@cabm.rutgers.edu

A6-35
S1RUCTIJRE OF 1HE RTP/DNA COMPLEX AND ITS ROLE IN POLAR FORKARREST

J.P. Vivian 1 , J.A. Wilce 2 , M.C.J. Wilce 1 1Dept. of Pharmacology/Crystallography
2 Dept. ofCentre University of Western Australia, Nedlands WA 6907
Chemistry /Biochemistry University of Western Australia, Nedlands WA 6907 .
The arrest of replication forks and the coordinated termination of DNA replicationin Bacillus subtilis is dependent upon the binding of the replication terminatorprotein (RfP) to its cognate DNA binding site (Ter site) . The cooperative binding of
two RfP dimers to the Ter site is able to arrest the helicase catalysed unwindingof duplex DNA in a polar manner. A complex between a 15N-labelled mutant formof RfP and a symmetrical form of a DNA binding site was formed using NMR
spectroscopy. By titrating the DNA, NMR was used to assess the stoichiometry ofcomplex formation , with the sample containing the most homogenous solution ofcomplex used in crystallization trials.
The 2.5A resolution structure reveals a novel DNA interaction by a dimeric"winged-helix" domain protein, which differs from the predicted models. As
expected the recognition helices of RfP are in contact with the major grooves of
the DNA. However, the "wings" and N-termini of RfP do not significantly contact
the DNA as forecast. This structure provides insight into the molecular basis ofpolar replication fork arrest and has been used to model the cooperative binding
in the functional terminator.
Email : jvivian@receptor. pharrn. uwa.edu.au

A6-36
STRUC'llJRES OF A SI'IE SPECIFIC MUTANT OF Plasmodium .falclparum
TRIOSEPHOSPHATE ISOMERASE AND ITS COMPLEXES.

Eaazhisai 1 , S .Parthasarathyl, H. Balaram2, P.Balaram 1 , M.R.N .Murthy 1 ,Biophysics Unit, Indian Institute of Science, Bangalore, India,
2Chemical Biology Unit, Jawaharlal Nehru Centre for Advanced Scientific
Research, Bangalore, India.

K.

1Molecular

Triosephosphate isomerase (TIM) is an extensively investigated glycolytic enzymethat catalysis the isomerization between dihydroxyacetone phosphate (DHAP)and
D-glyceraldehyde-3-phosphate(D-GAP). The mobility of loop 6 of the 13-barrel
domain of TIM is believed to be crucial for the efficient catalysis of the enzyme andfor preventing the release of the toxic intermediate, methylglyoxal. One of theresidues in that loop, Wl68, was mutated to Phe to monitor the resulting changes
at the active site. The mutant protein could be crystallized at pH 8.5 from TrisHCl using PEG 1450 as the precipitant in the presence of lOOmM Li2S0 4 . These
crystals diffracted to 2.3A resolution. Crystals of this mutant complexed to thenatural substrate DHAP and a substrate analogue 13-glycero phosphate (13-GP)
were also obtained under similar conditions. These crystals belong to theorthorhombic space group P2 12 12 1 and are comparable to the mutant crystals interms of diffraction quality. However, the mutant and its 13-GP complex contain
one dimeric molecule in the asymmetric unit in contrast to the DHAP complex,
which has two dimeric molecules in the asymmetric unit. These structures could
be determined by molecular replacement using the native TIM as the starting
model. In these complexes, the flexible loop 6 is in the open conformation in all
the monomers. Hence, mechanism of catalysis is likely to be distinct in theplasmodium enzyme.
Email : isai@mbu.iisc.emet.in

A6-37

COMPARATIVE ANALYSIS OF TilE S1RUC1URES OF A XYLANASE FROM
11IERMOASCUS AURANTIACUS DETERMINED AT ROOM AND CRYOTEMPERA1URES TO ATOMIC (1.11 A) AND ULTRA lDGH (0.89 A)
RESOLUTIONS.

R. Natesha, K. Manikandana, P. Bhanumoorthya, S. Ramakumm·a,b and M. A.
viswamitraa, Department of Physicsa and Bioinformatics Centreb, Indian Instituteof Science, Bangalore 560 012, India.

We have determined the crystal structure of a thermostable xylanase isolated
from Thermoascus Aurantiacus at atomic resolution of 1.11 A. at room
temperature and at ultrahigh resolution of 0.89 A. at cryo temperature withsynchrotron X-ray diffraction data. The structures have been refined to R/R-freeof 9.16, 11.67% respectively for room temperature data and R/R-free of 8 .85,
10.41% respectively for cryo data. We have carried out a comparative analysis of
the structures determined at the two temperatures. The F-family xylanaseassumes the (a/~) 8 triose phosphate isomerase fold with 303 amino acid residues
in the single chain. Upon least squares superposition of the corresponding ex
atoms of the structures, it is found that the interior ~-strands superpose withlower average RMS deviation of 0.08 A, the devia tions for the a-helices and loop
regions being 0.21 A and 0.22 A respectively. The helix a8 at the C-terminus haslarger deviation of 0.35 A. Structural plasticity of a few salt bridges at the twotemperature is noticed. From the analysis of the B-factor ratios, it is found thaton the average ~ - strands have lower ratios than a -helices. As expected from theleast square superposition analysis, a8 has more ratio compared to that of othersecondary structural elements. Hydrogen bonding patterns, water structure andanisotropic temperature factor distribution are also compared between the two
structures. Disorder of some of the amino acid residues is seen in the cryotemperature structure, which might explain the earlier observaion of the xylanase
to cleave xylan specifically without any contaminating cellulase activity.
Email : kmani@physics.iisc.emet.in

A6-38IONIZATION STATE, STOICIDOMETRY AND AMINO ACID AGGREGATION IN 1HE
COMPLEXES OF TARTARIC ACID WITH L-ALANINE AND L-IDSTIDINEHYDROCHLORIDE

K. Rajagopala, M. Subha Nandhinib, R.V.Krishnakumar: and S .Natarajanb,
aoepartment of Physics, Saraswathi Narayanan College, Madurai - 625 022 .
bDepartment of Physics, Madurai Kamaraj University, Madurai - 625 021, andcoepartment of Physics, Thiagarajar College, Madurai- 625 009.

As a continuation of crystal structure investigations on amino acid - carboxylic
acid complexes, we have recently elucidated the crystal structures of complexes of
L-alanine and L-histidine hydrochloride with tartaric acid. Some useful andimportant information on the ionization states and stoichiometry of the individual
molecules have been obtained. L-alaninium tartrate [P2 1 , a = 5 . 145(l)A, b =13.721(3)A, c = 7.475(l)A, ~ = 98.09(1) 0 , Z = 2) has the usually expected ionization
states and stoichiometry. The molecular aggregation pattern has striking
similarities with those observed in sarcosinium tartrate and L-prolinium tartrate.
In L-Histidinium hemihydrochloride ditartrate sesquihydrate, (C 6 H 12N3 0 22 +). 1/2(H+cz-). 2(C4H505-). _% H20 [C2 , a= 35.857(6)A, b = 7 .481(1)A, c = 7.678(1)A, ~ =93.19(2) 0 , Z = 4]. the L-histidinium moiety exists in the crystal as a dication. Boththe crystallographically independent tartaric acid molecules exist as semi-tartrateanions . Cl and a proton are found lying in the two-fold axis leading to theformation of a hemihydrochloride in the crystal. This proton, in tum, is also
shared between Cl and a water oxygen which lies very close to a two fold axis. A
detailed comparison of the conformation, stoichiometry and aggregation patterns
with other similar structures will be presented.
Email : s_natarajan50@yahoo.com

A6-39OBSERVATION OF ADDffiONAL CALCIUM ION IN 1HE CRYSTAL STRUCTURE
OF 1HE BOVINE PANCREATIC PHOSPHOLIPASE~ :K. Sekar4*, M. YogaveP , Ming-Jye Poi2,. A.A. Jeyaprakash3,
D. Velrnurugan 1 ,Ming-Daw Tsai2and V.Rajakannan 1 . !Department of Crystallography andBiophysics, University of Madras, Guindy Campus, Chennai - 600 025, India,
2Departrnents of Chemistry and Biochemistry, and the Ohio State Biochemistry
Program, The Ohio State University, Columbus, OH 43210, USA and 3Molecular
Biophysics Unit, 4 Bioinformatics Centre, Indian Institute of Science, Bangalore,
560 012, India.

Phospholipase A2 catalyses hydrolysis of the ester bond at the C2 position of 3 sn - phosphoglycerides. Here we report the l.9A resolution crystal structure of
the triple mutant K56, 120, 121M of bovine pancreatic phospholipase · A 2. The
structure was solved by molecular replacement method using the orthorhombic
form of the recombinant phospholipase A2. The refined protein model contains all
the 123 amino acid residues, two calcium· ions, 125 water molecules and one 2methyl-2-4-pentanediol (MPD) molecule. The final model has an R- factor of
19.6% [Rrree of 25.9%] with good stereochemistry.
The conformation of the~.
residues, 60 to 70, varies substantially compared to that of the trigonal and theorthorhombic forms of the recombinant enzyme. The notable observation in thepresent study is, in addition to the functionally important calcium ion in theactive site, one more calcium ion is found near the N-terminus. This is the firsttime such a second calcium ion is found in the bovine phospholipase A2
structure. The organic solvent MPD has also appeared in the active site of thestructure and its hydroxyl groups are involved in hydrogen bonding with the polar
atoms of the protein molecule as well as with two other water molecules, out of
which one water molecule is a natural ligand for the functionally important
calcium ion. The details will be presented
Email: sekar@physics.iisc.emet.in

A6-40PLANT LECTINS: DIVERSI1Y IN S1RUCTIJRE AND SPECIFICI1Y.
K. Suguna, A. Surolia and M. Vijayan. Molecular Biophysics Unit, Indian Instituteof Science, Bangalore-560 012, India.
Crystal structures of six different plant lectins belonging to three distinct
structural families, namely, peanut lectin and basic and acidic winged bean
agglutinins of the legume, jacalin and artocarpin of the Moracea and garlic lectinof the bulb families have been determined in our laboratory. The structures
revealed how carbohydrate specificity can be generated in different lectins byspecific residues at the carbohydrate binding sites, using water bridges,
posttranslational modification and oligomerization. Structures of the three legumelectins, peanut lectin with its unusual tetrameric association and the two dimericwinged bean lectins indicated that large variations in the mode of oligomerizationof legume lectins result from small variations in the amino acid sequence. A
phylogenetic analysis of legume lectins has also revealed that the primarystructures of legume lectins contain signatures of quaternary structure andcarbohydrate specificity. Tetrameric jacalin and artocarpin exhibit a novel lectinfold , the (3 prism I fold, whereas the dimeric garlic lectin has a (3 prism II fold.
Both peanut lectin and jacalin have a high affmity for T-antigen though thearchitectures of the two binding sites are entirely different.

Email: suguna@mbu.iisc.ernet.in

AB-41CRYSTAL AND MOlECUlAR S1RUCTIJRE OF DIETHYL 1ETRAHYDR0-1, 1DIOX0-3, 5-DIPHENYL-1, 4-THIAZINE-2, 6-DICARBOXYIA1E.

Vasua, C.Choodamanib, R.Banurekhac, Bhavanic and .K.A.Nirmalad · (a) Dept. ofPhysics , Vivekananda Degree College Malleshwaram, Bangalore-560055. (b)Dept.
of Physics,Government Science College, Bangalore 560001 . (c) Dept. of chemistry,
Annamalai University, Annamalainagar, Chidambaram. (d) Dept. of physics,
Bangalore University, Jnanabharathi, Bangalore 560056.
The title compound C22H25N06S is an intermediate derivative of tetrehydro-1, 4thiazine-1, 1-dioxide and is used in the synthesis of many pharmacologicallyimportant compounds . Tetrahydro-1, 4-thiazine-3,5-dicarboxylic acid, a
metabolite has been detected in the bovine brain as well as in human urine.
The compound was crystallized from chloroform by slow evaporation method atroom temperature. The crystals were colourless blocks, in the space group P 1
with lattice parameters a=10.217(l)A, b=10.713(2) A. c=11.397(l)A. a=98 . 14(l)O,,8=109.38(1)0, y=107.25(1)0 with number of atoms Z=2. density 1.323 mg/m3 ·volume=1083 .2(3) A3.
The structure was determined by direct methods and refmed to a final R-value
0 .054. There is disorder in one of the ethoxy group of the molecule, which could
not be detected by any other method. The interesting results of the structure
and conformation will be discussed in the presentation.
Email : nil:Tilalaka4 7@yahoo.com

A6-42APPUCATION OF RAPID SOAKED HALIDES IN PHASING PROTEIN S1RUCIDRES

Z. Dauterll·b M. Dauterll·b and K. R. Rajashankarb.c. asAIC/National Cancer
Institute, Frederick, MD 21702, USA, bBrookhaven National Laboratory, Bldg.
725A-X9, Upton, NY 11973, USA. <The Rockefeller University, 1230 York Avenue,
New York, N.Y. 10021, USA
A quick, less than a minute, soak of protein crystals in a cryo-solution containing
bromide or iodide anions leads to incorporation of these anomalous scatterers
into the ordered solvent region around protein molecules. The anomalous signal
from these halides can be used to solve the phase problem in protein
crystallography. This approach has been successfully used to solve several protein
structures. Details on soaking method, concentration of halides, soaking time,phasing successes and failures will be discussed at the meeting.
Email : raja@bnl.gov

A6-43ANALYSIS OF PR01EIN IN1ERFACES BY GRAPH SPECTRAL METIIODS

K.V. Brinda, N. Kannan and S. Vishveshwara. Molecular Biophysics Unit, Indian
Institute of Science, Bangalore 560 012, India.
The quatemary structures impart structural and functional credibility to proteins.
In a multi-subunit protein, it is important to understand the factors that drive theassociation or dissociation of the subunits. It is a well-known fact that bothhydrophobic and charged interactions contribute to the stability of the protein
interface. The interface residues are also known to be highly conserved. Though
they are buried in the oligomer, these residues are either exposed or partially
exposed in the monomer. It is believed that a systematic and objective meth9d ofidentifying interface clusters and their analysis can significantly contribute to theidentification of a residue or a collection of residues important for oligomerization.
Recently, we have applied the techniques of graph-spectral method to a variety ofproblems related to protein structure and folding. A major advantage of thismethodology is that the problem is viewed from a global protein topology point ofview rather than localized regions of the protein structure. In the present
investigation, we have applied the methods of graph-spectral analysis to identify
side chain clusters and their cluster centres at the dimer interface of a set of
homodimeric proteins. These clusters are analyzed in terms of properties such asamino acid composition, accessibility to solvent and conservation of residues.
Interesting results such as participation of charged and aromatic residues like
Arginine, Glutamic acid, Histidine, Phenylalanine and Tyrosine, consistent withearlier investigations, have emerged from these analyses. Important additional
information is that the residues involved are a part of a cluster(s) and that they
are sequentially distant residues which have come closer to each other in thethree dimensional structure of the protein. These residues can easily be detectedusing our graph spectral algorithm. This method has also been used to detect
dimerization sites on the monomer. The dimerization sites on the monomer havebeen identified as exposed and conserved clusters on the monomer, which also
have residues that are preferred at the interface. The dimerization sites thus
detected on the monomer are found to correlate very well with the actual
dimerization sites.

Email : brinda@mbu.iisc.emet.in

A6-44PRELIMINARY
X-RAY
ANALYSISOFPEROXIDASE FROM TOBACCO PLANTSCHLOROPLASTIC

ASCORBA'IE

Kei Wadaa*. Toshiji Tadaa. Yoshihiro Nakamuraa, Kazuya Yoshimurab, Shigeru
Shigeokab and Keiichiro Nishimuraa. aResearch Institute for Advanced Scienceand Technology, Osaka Prefecture University, Sakai, Osaka 599-8570 , Japan,
bOepartment of Food and Nutrition, Faculty of Agriculture, Kinki University,
Nakamachi, Nara 631-8505, Japan
Higher plants contain ascorbate peroxidase (APX) isoenzymes as H202scavengers. APX isoenzymes are distributed in at least five distinct cellularcompartments: stroma and thylakoid membrane in chloroplast, microbody,
mitochondria and cytosol. All of these APX isoenzymes require ascorbate (AsA) as
a specific electron donor. In particular, the chloroplastic isoenzymes are rapidly
inactivated in the absence of AsA, in contrast with other isoenzymes . We haveinitiated an analysis for the crystal structure of s .·omal APX from tobacco plants
to obtain some stereochemical information about the mechanisms of the rapid
inactivation and of the recognition of AsA as an electron donor.
The recombinant APX was overexpressed in Escherichia coli and purified bychromatography. The enzyme was crystallized by using PEG 4000 as aprecipitant. Data to a resolution of 1.6 A were collected using synchrotron
radiation at the Photon Factory, Japan. The crystals belonged to the orthorhombic
space group P2 12 12 1 with unit-cell parameters a= 37 .2, b = 76.8 and c = 98.8 A.
A molecular-replacement solution was obtained using the structure of cytosolic
APX from pea as a search model. Refinement of the model was performed,
resulting in an R-factor of 0.40 and an Rrree of 0.44. Manual modifications of themodel structure are currently in progress .
Email : keiwada@biochem.osakafu-u.ac.jp

A6-45

STRUCTURE AND ASSEMBLY OF TOBACCO NECROSIS VIRUS
K. Fukuyamaa, S. Jshitobia and T , Maedab, anepartment of Biology, Osaka

University, Toyonaka, Osaka 560-0043, Japan, and hDepartment of Plant
Sciences and Resources , Nihon University, Fujisawa, Kanagawa 252-8510 , Japan.
Tobacco necrosis virus is a spherical plant virus that is composed of ssRNA and180 chemically identical coat proteins. Its structure was determined by X-ray
crystallography at 2.25A 0 resolution. Three Stereochemically non-identical (A, B
and C) subunits are arranged according to icosahedral symmetry to form T=3
capsid , in which theN-terminal segments of the C subunits cluster around the 3fold (quasi 6-fold) axis. Five calcium ions per icosahedral asymmetric unit arelocated at the interfaces between subunits. Of these three are on the outer surfaceof the capsid. Virus particles were dissociated in 2M NaCl to protein and RNA,and they could be assembled by desalting to particles that are identical to thenative ones in EM . RNA appears to stabilize the particles. When the N-terminal
segment was cleaved off by limited proteolysis, the protein was assembled tosmaller spherical particles, probably T= 1 icosahedral particles. These assemblies
require calcium ion.
Email : fukuyama@bio .sci.osaka-u.ac.jp

A6-46

TRIPLE-HEI.JCAL S1RUCIDRE OF (PRO-PRO-GLY)9 IN THE c=80A CELL

Kenji Okuyamaa, Chizuru Hongoa, Guanghan Wua, Keiichi Noguchia, Yuji
Tanakab and Norikazu Nishinob, aFaculty of Technology, Tokyo University ofAgriculture and Technology, Koganei, Tokyo 184-8588, JAPAN and bKyushu
Institute ofTechnology, Kitakyushu, Fukuoka 804-8500, JAPAN
Recently, single crystal structures of collagen-model peptides have been reported
from several groups. Among these, peptides with simple repeating unit like (ProPro-Gly) 10 and (Pro-Hyp-Gly) 10 gave us only average structures in the c=20A
pseudo-cell since their diffraction patterns have remarkable features that there
are strong reflections on the layer lines corresponding to the helical repeating
period of 20A and very weak reflections on the rest of the layers. On the other
hand, single crystals of (Pro-Pro-Oly) 9 (P21. a=26.30, b=26.85 c=81.07A and~=90° ) showed a clear axial repeat of BOA together with the strong 20A repeat
along the c-axis (BIAOB2 , SPring-S). The triple-helical structure found in thiscrystal showed a very good agreement with the 7 /2-helical model for collagenproposed by one of the authors (K. 0.) . More than 150 water molecules were
found in an asymmetric unit. Many of them are involved in the hydrogen-bondschemes same as those observed in the other related model peptides.
Email: okuyamak@cc.tuat.ac.jp

A6-47REFINED MOLECULAR AND CRYSTAL STRUCTIJRE OF SllK I BASED ON Ala. Gly and (Ala-Gly) 2 -Ser-Gly PEPTIDE SEQUENCE

Kenji Okuyamaa. R Somashekarb,Keiichi Noguchia and Syuji Ichimuraa. Faculty ofTechnology, aTokyo University of Agriculture and Technology, Koganei, Tokyo 184,
Japan and bDepartment of Studies in Physics, University of Mysore,
Manasagangotri, Mysore 570006, India.
It is known that there are three silk modifications: Silk I of fibroin, Silk II of spunsilk and Silk III of fibroin in a solvent. Of these, Silk II crystal structure is very
well established. We report here the refined molecular and crystal structure of
one of the crystalline modifications of Bombyx mori, Silk I by X-ray diffraction
method . Cell dimensions are found to be essentially the same as in the synthetic
poly (L-Ala-Gly) peptide model. The (~,\j1) values of L-Ala and Gly in the repeating
unit are observed to be in the Bridge and the fourth quadrant regions ofRamachandran map and are given by (-ll2°, -6°) and (71° , -99° ) respectively.
The molecular conformation in the present study has a Crank-Shaft or an Sshaped zigzag arrangement leading to a remarkable agreement of observed andcalculated structure amplitudes for both dipeptide and :Pexapeptide sequences
and also has a reasonable hydrogen bond networks. Even though overallarrangement of the molecular chains appear to be similar (<j>,ljl) values are found to
be quite different from those reported by Lotz and Keith . In spite of intra- andinter-molecular hydrogen bond networks, silk I structure changes easily to thesilk II by a mechanical deformation.
This fragility may be due to the above
peculiar "Crank-Shaft" conformation deduced from the altemating structure ofalanine and glycine.

Email : rsshekar@sanchamet.in; rs@uomphysics.net

A6-48CRYSTAL STRUCTIJRE OF Nicotiana a1ata Sn 1-RNase ASSOCIA'IED WI1l:l
GAMETOPHYTIC SELF-INCOMPATIBILI1Y

Koh Idaab, Shigemi Noriokac, Masaki Yamamotob, Takashi Kumasakab, Eiki
Yamashitac, Ed Newbigind, Adrienne E . Clarked , Fumio Sakiyamace and Mamoru
Satoa.aoraduate School of Integrated Science, Yokohama City University,
Tsurumi-ku, Yokohama 230-0045, Japan hRIKEN Harima Institute, Mikazuki,
Sayo, Hyogo 679-5148, Japan clnstitute for Protein Research, Osaka University,
Suita, Osaka 563-0871 , Japan, dpJant Cell Biology Research Centre, School of
Botany, University of Melbourne, Victoria 3010, Australia elntemational Buddhist
University, Habikino , Osaka 538-8501, Japan
Nicotiana alata (ornamental tobacco) SF 11 -RNase is an S-glycoprotein associatedwith gametophytic self-incompatibility. Crystals of the SF 11 -RNase had beengrown at room temperature using polyethylene glycol as a precipitant. The crystal
structure was determined by MAD method with synchrotron radiation at RIKEN
Beamline I (BIA5XU) of SPring-8. The native crystal diffracted beyond 1.55 A
resolution. The protein consists of eight a-helices and seven ,8-strands. The
tertiary structure is the typical motif of the RNase T2 family, which composed of avariant of the (a + ,8) fold . Asn28 was linked with Hybrid-type ollgosaccharides.
The residues that serve as the catalytic acid and base are assigned to His32 andHis91, respectively. Two 'hypervariable' regions. known as HVa and HVb , are theproposed sites of S-allele discrimination during the self-incompatibility
recognition, and in the SF1 1-RNase, these are separated from the active site. HVaand HVb are composed of the positively charged long loop followed by the part ofan a -helix (Lys47-Leu63) and the negatively charged short a -helix (Phe72-Pro82),
respectively. The SF1 1 -RNase structure shows both hypervariable regions areaccessible to the solvent and could participate in the process of self-nonself
discrimination between S-RNa se and unknown pollen S-gene product(s) upon .
pollination.

Email : idakoh@spring8 .or.jp

A6-49AB-INITIO PHASING OF A PROTEIN CYI'OCHROME C6 BY DIRECT METHOD.

Krishna Chowdhm:ya, Soma Ghoshb and Monika Mukherjeea, aoepartment of
Solid State Physics, Indian Association for the Cultivation of Science, Calcutta
700 032, India, and bDepartment of Physics , St. Xavier's College, Calcutta 700
016, India.
Cytochrome C 6 , obtained from the green alga monoraphidium brauni, is a 89
amino acid heme-containing redox protein with 151 solvent water molecules havebeen redetermined, ab-initio, from a single native Synchrotron X-ray data set
without using any known fragment or MIR phases. Several thousand phase sets
at 1.1A resolution were generated with 1200, 1500 and 2000 largest IE J values
using MULTAN. TheE-map corresponding to the phase set having lowest mean
phase error (MPE) 45 .4° showed an octahedral coordination around the Fe atom.
Successive difference Fourier maps followed by least squares refinement using
SHELXL97 converged to R=0.30. The protein model building was, however,difficult owing to discontinuity in the polypeptide chains. To improve the qualityof the electron density map , the density-modification procedure was tried. Initial
phases calculated from Fe, (Fe+S). (Fe+S+3N) coordinates obtained directly fromthe E-map of MULTAN with 40 cycles of refinement by density modification
changed MPE from -70° to -40° (the map correlation coefficient from -0.33 to-0. 72) and resulted in an interpretable electron density map. The successful
application of direct method in reciprocal space along with density modification inreal space reveals the possibility of substantial automation in the structure
determination of metalloproteins with high resolution data.

Email : sspmm@iacs.res.inA6-50CRYSTAL S'IRUCTURE ANALYSIS OF A CYCWPHANE

L.Damodharan 1 , Vasantha Pattabhi 1 , Sambasivarao Kotha2 and Somnath Halder2
1. Department of Crystallography and Biophysics, University of Madras, Chennai
600 025, India. 2. Department of Chemistry, Indian Institute of TechnologyBombay, Powai, Mumbai 400 076, India
Cyclophanes represent the central class of synthetic receptors in molecular
recognition. The aromatic structural units present in them ensure the necessary
rigidity of the molecular structures and also provide orientation sites for thecooperative binding of the guests. We have synthesised for the first time acyclophane molecule with unusual amino acid (cx-aminoiso butyic acid) unit as aside-chain. We report here the crystal structure of this novel molecule.
Cyclophane crystallises in the triclinic system with unit cell parameters a =ll.332(4)A, b = 12.984(4)A, c = 15.787(2)A, ex = 78.00(2} 0 , ~= 76.45(2} 0 , y =88.39(3} 0 , V= 2213(1)A3, Z=2. Density= 1.143(Mg I m 3), A.= 0.71069 A, 1J. = 0.78
cm- 1. F(OOO) = 806 and space group Pl. The structure was solved by direct
methods and refined by blocked full matrix method. Final R-factor is 0.12 .
Hydrogens were fixed and riding atom corrections were applied to them duringrefinement. The crystal asymmetric unit contains two molecules . Hydroquinone,
acetonitrile, ethanol and water have also been located in the crystal structure.
The two cyclophane molecules are oriented almost perpendicular to each other.
Each cyclophane molecule has two N-H ... O intra-molecular hydrogen bonds. The
hydroquinone links the two symmetry related molecules through a C-H .. .O
hydrogen bond. The NH-CO groups are oriented on opposite directions withrespect to the macrocycle.
Email : laksdhamu@yahoo.com

A6-51X-RAY CRYSTAL STRUC1lJRE DETERMINATION OF 3-[(4-HYDROXY-8-ME1HYL2-0X0-2H-CHROMEN-3-YL)-CHLOROPHENYLMETI IYL]-8-E1HYL-2-0X0-2HCHROMEN-4-0IATE

L. Vijayalakshmia· V. Pa rthasarathia, Vipul Vorab, and Anamik Shahb ,aoepartment of Physics, Bharathidasan University, Tiruchirapalli-620 024, India,
and boepartment of Chemistry, Saurashtra University, Rajkot-360 005, Gujarat.
India.

The title compound otherwise known as dicoumarol has received importancerecently for its pronounced antiHIV study by various researchers. They were
tested for inhibition of related retroviral integrase form HIV-2 and Simian
immunodeficiency virus(SIV). They are found to be inhibited with 3'-processing
and strand transfer activities against HIV-1 and HIV-2 and SIV integrases , withno remarkable selectivity noted . It was found that the role of substitution on
benzenoid part would have some specific effect on these structures as integrase
inhibitors. In the present investigation, the structure determination was carriedout to study the hydrogen bond characteristics and to find out the possible
structure activity relationship.
A d erivative of dicoumarol, C 27 H 19 0 6 Cl, Mr =474.9, monoclinic, P2Ifc, a =11.307(3) ; b = 10.488 (4), C = 19.004.(6) A ; f3 = 92 .89(3) 0 ; V = 2250 .8 (13) A3 , Z = 4 , Dx
= 1.401 Mgm-3, A.= 0.71073 A , 11 = 0 .21mm· 1 , F[ooo) = 984 , T = 293 K, wR =0.180 and final R = 0 .068 for 2277 observations. In the title compound, two 4hydro:xy coumarin moieties are linked through a methylene bridge on which oneof the two hydrogens has been replaced with a phenyl group.
The coumarin rings are individually planar with the two planes inclined at 57.4
(1) 0 to each other. The phenyl mean plane is inclined at 63.5 (1) 0 to one and63 .8(1) 0 to the other 4-hydro:xycoumarin. All principal bond angles about
methylene carbon are widened over normal tetrahedral values . Sterle crowding
about the methylene carbon may be responsible for this feature. The orientationsof the coumarins about the methylene bridge may be described by torsion angles
C4-C3-C2l -Cl3- 84.0 (6) 0 and C3-C21-C13-Cl2 83.5(5) 0 • The C2l-C22 distanceof l.545(6)A is longer than an unstrained C(sp3)-C(Ar) bond , but in the range
characteristic of related sterically crowded structures . The 4 -hydro:xycoumarins
are intramolecularly hydrogen bonded between hydroxyl and cabonyls, with 0 .. .0
separations 2 .598 and 2 .688 A respectively.
Email : a rthy936@yahoo.com

AS-52CRYSTAL AND MOLECULAR S1RUC1URE OF 2 [N-(2,6-DICHLOROPHENYL) -20XOINDOLIN-3-YLIDENE] ME'IHYL PHENYL ACETATE

L.Vijayalakshmia· V.Parthasarathia, Narasinh Dodiab and Anamik Shahb,
Department of Physics, Bhara thidasan University, Tiruchirapalli-620 024, India,
and b Department of Chemistry, Saurashtra University, Rajkot-360 005, Gujarat.
India.
Indole derivatives, widely distributed in living cells as tryptophan metabolites ,have important biological functions . They are found to possess CNS depressant,antidepressant, antihypertensive, psychotropic muscle relaxant, anti-microbial
and anti-inflammatory activities. The interaction of indole with DNA has been
widely reported . The structure determination of the title compound was taken up
to .study the effect of the substituents and also the conformation of theoxoindoline ring. This compound C 23 Hl 5 N0 3Cl2 crystallizes in the monoclinic
space group C2/c with Z = 8. Cell parameters: a =16.724 (2) ; b = 8.739(2), c =28.287(11) A; f3 = 98.8(1) 0 ; V = 4085.8 (8) A3 , Dx = 1.380 Mgm-3 , A.= 1.5418 A ,fl = 3 .063mm· 1 , Mr =4 24.26 , F(OoO) = 1744 , T = 293 K, wR = 0.138 and final R= 0.053 for 3873 observations .
The phenyl and the oxoindoline rings are planar. The substitution of methyl groupin one of the phenyl rings prevents coplanarity between oxoindolin and thisphenyl ring. The dihedral angle between them is 52.1(1) 0 • The methyl acetategroup makes an angle of 74.0(8) o with oxoindolin ring and 81.9(11) o with thisphenyl ring. The magnitude of the dihedral angle [81.9(11) 0 ) appears to be acommon feature among the acetic acid or carboxylate as substituent group. This
dihedral angle is observed to be either close to 0 or 90° in all plant growth
hormones. In the present structure, the methyl a cetate moiety adopts n early
perpendicular orientation with respect to this phenyl ring. The bond length C2-03
and Cl1-03 show partial double bond charact er. C--H .. O type intermolecularhydrogen bonds are formed in the title compound.
Email: arthy936@yahoo .com

A6-53

CRYSTALLOGRAPIDC SIDDIES OF CAD DOMAIN OF DFF45

Li T . 1 , Yang W. 2 ,Zhai Zh.H. 2 , Rao Z.l. l Laboratory of Structural Biology,
Protein Science Laboratory of MOE, School of Life Sciences Engineering, Tsinghua
University, Beijing l00084,China. 2 Department of Biology, University of Beijing.

Apoptotic DNA fragmentation and chromatin condensation are mediated by DFF,
a heterodimeric protein composed of a 40kD caspase-activated DNA
fragmentation factor (DFF40) and its 45kD inhibitor (DFF45) . In non-apoptotic
cells, DFF40 is kept as an inactive complex with its inhibitor DFF45. Whenvarious apoptotic stimuli activate the caspase cascade, caspase 3 cleaves DFF45
and the released DFF40 degrades chromosomal DNA in nuclei. The CAD domain
of DFF45 executes the function of inhibiting the DNase activity of DFF40 and
helping in its correct folding as a chaperone.
We cloned the human DFF45 CAD domain into pQE-30 vector and expressed it asa His-tag protein. The purified DFF45 was obtained by Ni-NTA affinity
chromatography followed with resource-Q ion exchange column. We now havecrystals by vapor diffusion in hanging drops. Preliminary X-ray crystallography
study is in progress .
This research will give useful information for learning the mechanism of DNA
fragmentation process in apoptosis.

AB-54
PURIFICATION, CRYSTALLIZATIONVESICULAR DISEASE VIRUS.

AND

X-RAY

ANALYSIS

OF

SWINE

Lin. W., Zhao, Q.#, Zhang, B., Bartlam, M., Ding, Y., Li, D.#, Chen, Y.#, Bao, H.#,Ren, J., Zhang, H., An, J ., Liu, Y., Jiang, F ., Dong, Y. , Xie, Q.#, & Rao.Z* .
Laboratory of Structural Biology & MOE Laboratory of Protein Science, School ofLife Science and Engineering, Tsinghua University, Beijing 100084 China.
#Lanzhou Veterinary Research Institute, Chinese Agricultural Science, Lanzhou
730046. China
Swine vesicular disease virus (SVDV) is the etiological agent of swine vesiculardisease, a highly contagious disease in pigs, and is related to Coxsackie B virus .
Crystalline arrays of SVDV can be observed in the cytoplasm of cells 4.5 hours
after inoculation to porcine kidney cells (IBRS-2 cells). We obtained crystals fromvirus isolated from two cell lines of the JX/78 strain of SVDV and present the
crystallization conditions together with preliminary X-ray data to 3.6 A resolution.
Email: raozh@xtal.tsinghua.edu.cn

A6-55
CRYSTALLOGRAPHIC STUDIES(F87L/Y96F /L244A/V247 A)

OF

CYTOCHROME

P450CAM

MUTANT

Liu Binbin, Sun Lei 1 • Chen Yuhan, Chen Xuehui, Liu Yiwei Tan hong Wang
L#&Zihe Rao. Laborato'ry of Structural Biology, Department of Biological Scienceand Technology & MOE Laboratory of Protein Science, Tsinghua University,
Beijing 100084, China. #Lab of Inorganic Chemistry, Oxford University, Oxford
OX1 3QU.
Cytochrome P450 enzymes are heme-containing monooxygenases, which are
involved in many vital processes in the biosythesis and degradation of steroids
and other hormones, as well as in the metabolism of xenobiotics. Cytochrome
P450cam from Pseudomonas putida is by far the most characterized member of
the P450super-family. The structure of the enzyme complexed with the natural
substrates and many other substrates and inhibitors has been studied
crystallographically.
We got several constructors of P450com mutants from the lab of Dr.L.L.Wong,
Oxford University.We studied four site mutants (F87L/Y96F /L244A/V247A). The
mutants were expressed in E.coli BL-21, induced with 1mM camphor,purified
through DEAE Sepharose F.F.at pH6.5,FPLC at pH7.4(ResourceQ 1ml) at pH7.4
Superdex75 at pH7.0. Crystals of the protein were obtained at 298K by the vapordiffusion method using PEGSOOO as a precipitant. 1ul of protein solution was
mixed with 1ul of 30%PEG8000 in buffer [100mM cacodylate, 200mM sodium
Acetate pH6.5]. Crytals appear within 1 day. After data was collected by X-ray
diffraction, the structure was determined by Isomorphous Difference Fourier
method. Its space group is P2 1 and unit-cell parameters are a=67.011 , b=62 . 187,
c=95.561A. 13=90.571 °.Now we are also studying the complex of the mutant with
its substrate, phenanthrene.
Key words : Cytochrome P450 mutant Crystallization

A6-56
UNUSUAL IONIZATION STA1E, STOICIDOME1RY AND
BIS(DL-SERINIUM) OXALA.1E DlliYDRA1E

AGGREGATIONIN

M. Alagara, M. Subha Nandhinib, R.V.KrishnakumarC and S.Natarajanb,
aDepartment of Physics, ANJA College, Sivakasi - 626 123. bDepartment of
Physics, Madurai Kamaraj University, Madurai - 625 021, and cDepartment of
Physics, Thiagarajar College, Madurai- 625 009.
X-ray studies on crystalline complexes of amino acids with simple carboxylic
acids, which are believed to have existed in the prebiotic earth, are expected toprovide useful and important information on the nature of intermolecularinteractions and biomolecular aggregation patterns, at atomic resolution. The
crystal structure of bis(DL-Serinium) oxalate dihydrate, 2(C 3 H 8 N0 3 +).C 2 0 2 2-.2H2 0[P2Ifc, a= 4.869(l)A, b = 17.199(7)A, c = 17.172(4)A, ~ = 91.68(2) 0 ] has been
determined and refined to R = 0.037 for 2528 observed reflections . The
asymmetric unit contains two cry~tallographically independent serinium cations ,.
a double negatively charged oxalate anion (uncommon in similar crystal
structures) and two water molecules. The oxalate anion lies across the inversion
center. There are no direct interactions between the amino acid molecules . The
oxalate anions and water molecules mediate interactions between amino acidmolecules in forming a layer parallel to the ab plane. The aggregation pattern of
the individual molecules is distinctly different from those observed in other aminoacid - oxalic acid complexes. A detailed comparison of the ionization state,characteristic aggregation and interaction patterns with other similar complexes
will be presented .
Email : s_natarajan50@yahoo .com

A6-57

CRYSTAL AND MOLECULAR STRUCWRE OF A NOVEL TIIIENOPYRIDINE: 2CARBE1HOXY-3-AMIN0-4-(4-METHYLPHENYL)-6-PHENYLTIIIEN0[2,3-B]
PYRIDINE

U. H. Patela , C.G.Daveb , M. M. Jotania. H. C. Shahb, anepartrnent of Physics,
Sardar Patel University, Vallabh Vidyanagar-388120,Gujarat,India, bQrganic
Syntheses Laboratory, M.G. Science Institute, Navrangpura, Ahmedabad380009, Guj a rat. India.
Thieno[2 ,3-b)pyridines are isosteres of isoquinoline.Some of the thienopyridine
show an important biological properties such as antimicrobial, antihypertensive,
antidiabetic etc. and interesting biological activities of these compounds are also
observed in nature. Therefore to correlate the structure-function relationship ,crystal and molecular structure of 2-carbethoxy-3-amino-4-(4-methylphenyl)-6phenyl thieno[2,3-b)pyridine is determined. The compound crystallizes in a
monoclinic system having a space group P2Ifc. The crystal parameters are: a =9.200(3). b = 22.465(5). C = 9.708(3}A, {3 = 94.06(3} 0 , Z= 4, V = 2001.4(1) A 3, Pc =1.289 Mg m-3, 11- = 0 . 183 mm-1 . Final residual index is 0.0586 for 3513 uniquereflections. Thiophene ring is coplanar with pyridine ring plane. One of the phenyl
ring is almost coplanar with pyridine ring having dihedral angle 5.18(22) 0 whereas
other one is inclined at 69.64(12) 0 to the pyridine ring plane. As usual inheterocyclic compounds, the structure is mainly stabilized due to weak van der
Waal Interactions.
Email : mmjotani@yahoo.com

A6-58CRYsTAL S1RUCTURE OF AN "EX'IERNAL" FUNTIONAL UNIT FROM Rapcma
thomasicma HEMOCYANIN

M. Perbandta. E. Guthohrleina, , S. Stoevab, , K. Idakievac K. Parvanovac, N.
GenoVC W. Voelterb and C. Betzela, auniversity of Hamburg, Dept. of Biochemistry
and Molecularbiology, 22603 Hamburg, Germany, bUniversity of Tiibingen, Dept.
of Physiological Chemistry, 72076 Tiibingen, Germany and csulgarian Academy of
Science, Dept. of Organic Chemistry. Sofia 1113 Bulgaria.
thomasiana hemocyanin is a representative of giant molluscan(gastropodan) dioxygen-transporting proteins. The cylindrical hemocyanin
aggregates are composed of two structural subunits, RHSS1 and RHSS2. The 420
kDa subunit RHSS2 contains eight 50-55 kDa functional units. Each unit has asingle dioxygen-binding dinuclear copper-containing active site. Molluscan
hemocyanin functional units can be subdivided into "internal units" , forming theso called "arch" inside the hemocyanin cylinders , and "external" units, building
the cylinder wall of the aggregates. The "external" oxygenated functional unit
RtH2-e of the Rapana hemocyanin subunit RHSS2 was isolated and crystallized.
Intensity data were collected to 3 .3 A at 120 K using synchrotron radiation.
Molecular replacement calculation with the "internal" subunit Odg from Octopus
dojleini as the search model led to satisfactory structure solution with threemolecules per asymmetric unit.

RapanaRefinement and model building, currently at an R-factor of 0.25 (Rrree of 0.33) arestill in progress. Interestingly some kind of molecular self-assembly can beobserved by the crystal structure. The monomers interact in a "head to tail"manner and are stabilised by intermolecular interactions revealing a noncrystallographic trimer. Furthermore two trimers are related by a crystallographic
two-fold axis. As a result regular hexameric cylinders are the repeating
component in the crystal structure.
Email : markus@unisgil .desy.de

A6-59S'IRUCTIJRE OF TilE BINDING DOMAIN OF 1ETANUS NEUROTOXIN INCOMPLEX WTIH DOXORUBICIN

M.N. Ponnuswamy 1·2 • D. Kumaran 1 , S. Eswaramoorthy 1 and S. Swaminathan 1 .
1Biology Department, Brookhaven National Laboratory, Upton, New York 11973,
USA. 2 Department of Crystallography and Biophysics , University of Madras,
Guindy Campus, Chennai - 600 025, INDIA.
Clostridial neurotoxins comprising the seven serotypes of botulinum neurotoxin
and the tetanus toxin are so far the most potent neurotoxins known to affecthumans. They cause spastic and flaccid paralysis in humans. Biochemical,
electrospray ionization mass spectroscopy (ESI-MS} and computation docking
studies have shown that doxorubicin, a well- known DNA intercalater, binds tothese neurotoxins. Here we present the crystal structure of the C-fragment of
tetanus toxin complexed With doxorubicin to identify the binding site for the drug
and its interaction with the protein molecule. The crystals of the complex wereprepared by soaking native crystals in the mother liquor containing doxorubicin.
X-ray diffraction data were collected at the liquid nitrogen temperature at the
National Synchrotron Light Source, Brookhaven National Laboratory. The drug
molecule was identified from the difference Fourier map and the structure wasrefined using CNS until convergence. Doxorubicin binds in a site that has been
identified as the binding site for gangliosides. Doxorubicin stacks against theconserved residue Trp 1289 and interacts with another conserved residue, His
1271. Results from this study and their implications in drug design will be
discussed.
Research supported by the Chemical and Biological Non-proliferation ProgranNN20 of the U.S. Department of Energy under Prime Contract No . DE-AC0298CH10886 with Brookhaven National Laboratory is gratefully acknowledged .
Email : mnpsy@hotmail.com

A6-60

INTER ATOMIC CONTACTS IN CRYSTALS OF VIRAL CAPSIDS

M.R.N. Murthy, Molecular biophysics Unit, Indian Institute of Science, Bangalore
560 012, India
Spherical viral capsids possess icosahedral symmetry and are made of a large
number of protein subunits, each subunit consisting of thousands of atoms.
When crystallized, the capsids pack densely resulting in a large number of closeinteractions between atoms of neighboring virus particles. The contacts between
atoms of protein subunits within a virus particle are important for understanding
the forces responsible for the integrity of virus particles. Similarly, interactions
between virus particles are also of much interest. However, evaluation of the
distance between several hundred thousand atoms of one virus particle and thoseof another is a non-trivial computational task. A method based on representing
the three dimensional shape of the virus particle as a binary map allows thiscomputation to be accomplished with minimal computational requirements. This
representation could be of some general interest in the examination of the spatial
relation of three-dimensional objects.
Email : mm@mbu .iisc.emet.in

A6-61STRUCURE OF A TERNARY COMPLEX OF 'IRYPSIN WITH BENZAMIDINE AND A
NA1URAL INIDBITOR AT ATOMIC RESOLUTION

Manashi Sherawata, Punit Kaura, Christian Betzelb, T.P. Singha, aDepartment ofBiophysics, All India Institute of Medical Sciences, New Delhi 110 029, India , andbinstitute of Medical Biochemistry and Molecular Biology, UKE. C/0 DESY
Notkestrasse 85 , 22603, Hamburg, Germany.
Proteases are a group of abundant enzymes serving a variety of different functionsin the living organisms. Mechanistically, they can be subdivided into four different
groups: serine, aspartic, thiol and metalloproteases. Trypsin is a serine proteaseinvolved in digestion. The catalytic triad in trypsin comprises Asp 102, His 57 andSer195, which are interconnected via hydrogen bonds. In order to understand thefunctional mechanism precisely. the structures of macromolecules at atomic
resolution are required. Refinement of such structures routinely incorporates therefinement of anisotropic temperature factors which aid in the delineation of loop
motions and far ranging disorder: The recognition of hydrogen atoms and theidentification of the protonation states and the disposition of hydrogen atoms iscritical to further our understanding of structure and function of enzymes. The
trypsin was cocrystallized with benzamidine and a designed synthetic inhibitor.
The crystals belong to trigonal space group P3 22l with a=b=68.55, c=73.33A anddiffract to 0.97A resolution. The a symmetric unit contains l trypsin molecule, 449
water molecules, 1 calcium ion, l benzamidine molecule, 1 ethane sulfonic acid, 1
glycerol molecule, two molecules of the inhibitor and 1603 H-atoms. The structure
has been refined to an R-factor of 13.4% (Rrree=l7.9%). The two molecules of theinhibitor completely saturate the binding site and also interact directly with Q Y of
Serl95 and Ne2 of His57. The molecules of benzamidine are held on the surface
and fill the interstitial sites. There are clear electron density peaks for thehydrogen atoms associated with the Q Y of Serl95 and N81 of His57.

Email : manashi_s@hotmail.com

A6-62CRYSTAL S'IRUCnJRE OF A MANNOSE-SPECIFIC LECTIN, CONCANAVALIN A
BOUND TO A PORPHYRIN, m~TE'ffiASULPHONATOPHENYLPORPHYRIN.

Manisha Goela, Deepti Jaina, Kanwal J . Kaux-a. Roopa Kenothb, Bhaskar G.
Maiyab, Musti J. Swamyb, . Dinakar M. Salunkea. astructural Biology Unit,
National Institute of Immunology. New Delhi - 110 067, India. bSchool ofChemistry, University of Hyderabad, Hyderabad 500 046, India.
Concanavalin A (ConAl is an extensively studied plant lectin, known to bind to
mannose rich complex carbohydrates. Recently ConA was reported to bind avariety of porphyrins. In the present study, the crystal structure of Concanavalin
A complexed withmeso-tetrasulphonatophenylporphyrin (H 2TPPS) was
determined at 1.9 A resolution. The crystals obtained belong to space group F222
with cell dimensions of 106.0, 117.3 and 126.0 A. The sulphonatophenyl group of
the H 2TPPS molecule occupies the same binding site on ConA as that of methyl a.D-mannopyranoside, a natural ligand. A pair of stacked porphyrin molecules
stabilizes the crystal structure by end-to-end cross-linking with ConA. Thiscrosslinking of lectin brought about by non-covalent interactions is similar to thatobserved in other lectins in complex with various biantennary carbohydrate or
glycopeptide ligands. The porphyrin binds to ConA predominantly throughhydrogen bonds and water-mediated interactions. Comparison of the crystal
structure of ConA in complex with methyl a.-D-mannopyranoside and H 2TPPS
shows excellent equivalence of interactions . Seven of the eight hydrogen bonds
observed between methyl a.-D-mannopyranoside and ConA are mimicked by thesulphonatophenyl group of porphyrin after incorporating two water molecules .
Email : manishag@nii.res.inA6-63
S1RUCTURE OF 1HE 20S PROTEASOME FROM BOVINE LIVER AT 2. 75 A
RESOLUTION

M.Unnoa, T. Mizushimaa, Y. Morimotob, Y. Tomisugib, K. Tanakac, N. Yasuokab
and T . Tsukiharaa alnstitute for Protein Research, Osaka university, hDepartmentof Life Science, Himeji Institute of Technology AND CTokyo Metropolitan Instituteof Medical Science (Rinshoken)
Proteasome has a molecular weight of 750 kDa and sedimentation coefficient ofapproximately 205. It is composed of two copies of hetero-heptameroH:ype
subunits and {J-type subunits, (a l-7 fJ l-7) 2 in eukaryotic cells, and otherwise
homo-heptamer of identical a - and fJ -type subunits , (a 7 fJ 7) 2 in prokaryotic
cells. In mammalian cells, three additional non-essential subunits of the 20S
proteasome , LMP2 , LMP7 and MECLl can replace constitutive components upon
induction by the T-cell-derived antiviral cytokine interferon- y. It is known thatmammalian proteasome is involved in generating antigen peptide that ispresented by class I MHC molecule.
We determined the structure of 20S proteasome from bovine liver at 2 . 75 A
resolution using the molecular replacement method with the structure of yeast
20S proteasome as a search model. The electron density IJlap was interpretablewithout any collision in the orthorhombic crystal lattice. Model building andstructure refinement have been completed. We found a putative new active sitethat was different from yeast proteasome.
Email : unno@protein . osaka-u ~ ac.jp

AS-64
S1RUCTIJRE AND DYNAMICS OF TilE CENTRAL STALK IN ATP SYNTHASE:LARGE CONFORMATIONAL CHANGES IN 1HE £-SUBUNIT REGUI.A1E TillS
ROTARY MOTOR EN~ VIA A RATCHET MECHANISM

Andrew J. W. Rodgers*. Satoshi P. Tsunodat , Robert Aggeler*, Masasuke
Yoshidat , Roderick A. Capaldi* and Matthew C. J. Wilce* , * Department ofPharmacology and Crystallography Center. University of Western Australia,
Nedlands, WA 6907, Australia; *Institute of Molecular Biology, University ofOregon, Eugene, Oregon 97403-1229, USA: tchemical Research Laboratory (R-1).
Tokyo Institute ofTechnology, 4259 Nagatsuta, Yokohama 226-8503, Japan
FoFI ATP synthases utilize energy from a transmembrane proton gradient tosynthesise ATP in bacteria, mitochondria and chloroplasts. In bacteria, theenzyme can hydrolyse ATP to generate a proton gradient (Senior, 1990) . Previous
studies had established that the central stalk, made of the y and E subunits in theF, part and c subunit ring in the F 0 part, rotates relative to a stator composed of
a3 ~38ab2 during ATP hydrolysis and synthesis. How this rotation is regulated has
been less clear. Here we show that the E subunit plays a key role by acting as aswitch of this motor enzyme.
Two different arrangements of the £ subunit have been visualized recently. The
first has been observed in beef heart mitochondrial F I-ATPase where the Cterminal portion is arranged as a two a-helix hairpin structure. which extends
away from the a 3 ~ 3 region, and toward the position of the c subunit ring in the
intact FIFo (Gibbons et al., 2000) . The second arrangement was observed in the
structure of a complex of the y and E subunits of the E. coli F I-ATPase (Rodgers
and Wilce, 2000). In this . the two C-terminal helices are apart and extend along
the y to interact with the a and ~ subunits in the intact complex.
We have been able to trap these two arrangements by cross-linking after
introducing appropriate Cys residues in E. coli FIFo. confirming that bothconformations of the E subunit exist 'in the enzyme complex. With the C-terminal
domain of £ toward the F 0 , ATP hydrolysis is activated but the enzyme is fully
coupled in both ATP hydrolysis and synthesis . With the C-terminal domain
toward the FI part, ATP hydrolysis is inhibited and yet the enzyme is fully
functional in ATP synthesis, i.e. it works in one direction only. These results help
explain the inhibitory action of the E subunit in the FIFo complex and argue for aratchet function of this subunit.
l. Senior. A. E. (1990) Annu. Rev. Biophys. Biophys. Chem. 19, 7-41
2 . Gibbons, C., Montgomery, M. G. , Leslie, A. G. W. & Walker, J . E. (2000)
Nature Struct. Biol. 7, 1055-1061
3. Rodgers, A. J. W. & Wilce, M. C. J. (2000) Nature Struct. Biol. 7, 1051-1G54

Email : mwilce@receptor. pharm.uwa.edu.au

A6-65
1WO AL1ERNA1E FACES ' OF ME1HOXYIA1ED CYTOSINE RESIDUES FORPAIRING WITH G AND A IN 1HE WATSON-CRICK GEOME1RY, LEADING TO
PURINE 1RANSffiON MUTAGENESIS, .

Md. Tofazzal Hossaina, Takaaki Hikimaa, Toshyuki Chatakea, Masaru Tsunodaa,
Yoshihito Uenob, Akira Matsudab, and Akio Takenakaa, aoraduate School of
BioScience and Biotechnology, Tokyo Institute of Technology, Yokohama 2268501 , Japan, and bGraduate School of Pharmaceutical Sciences, Hokkaido
University, Sapporo 060-0812 , Japan
Methoxyamine is known to be a potent mutagen, which attacks cytosine moiety to
produce N4 -methoxycytosine (mo 4 C). This chemical modification induces purine
transition (A<--->G) during DNA replication. The DNA polymerase accepts only
the Watson-Crick base pairs in B-form DNA. To investigate the interaction
property of mo 4 C residues in B-form DNA, crystal structures of DNA dodecamers
with the sequences d(CGCXAATTmo 4 CGCG). (X=A and G) have been X-ray
analyzed. In either dodecamer. the oligonucleotides are associated to form a Bform duplex. In the dodecamer with X=G, electron density maps show that one of
the two mo 4 C residues is in the amino tautomeric state with an anti methoxy
group forms a canonical Watson-Crick base pair with the guanine residue of the
opposite strand , and that the other mo 4 C residue is in the imino tautomeric statewith a syn methoxy group and forms a base pair with the guanine residue in the
wobbled geometry. While in the case of X=A, the mo 4 C residues are in the imino
tautomeric state with an anti conformation form pairs with adenine residues at
the two sites. The pairing geometry is very similar to the Watson-Crick type .
Based on these interaction geometry, two routes for purine transition .mechanism
have been proposed.
Email : thossain@xtal.bio.titech.ac.jp

AB-66EXPRESSION, PURIFICA'TION, CRYSTALLIZA'TION .t)ND X-RAY STRUCnJRE OF
HETERODIMER OF InV-1 PROTEASE

Mukesh Kumar, K. K. Kannan & M.V.Hosur*. Solid State Physics Division,
Bhabha Atomic Research Centre, Trombay, Mumbai-400085
An altemative strategy to small molecule inhibitors that target the active site of

HIV-1 protease, is to engineer a molecule that disrupts the dimerisation of theprotease. Such a strategy is going to be more immune to the problem of drug
resistance mutations. 3-D structure of hetrodimers are shown to be important forthe design of such a molecule. Heterodimer of HIV-1 protease containing C95M
mutation on first monomer and C95A mutaion on the second monomer wasoverexpressed in the E Coli strain BL21 DE(3) pLysS and the protein was
extracted and purified for crystallization. Crystals were obtained by hanging drop
vapor diffusion method with reservoir containing ammonium sulfate in phosphate
citrate buffer. The crystals diffracted to 2 .1 A resolution on our Rigaku x-ray
generator R-AXIS IIC illJ.age plate detector system. 44 oscillation frames werecollected with 1° oscillation. The data was processed using DENZO and unit celldimensions were found to be a=b=6l.06 A and c=83.42 A. Scaling was done by
SCALEPACK and the Rmerge was 7.9% in the space grooup P6 1 . Completeness ofthe data was 93.5%. The structure was refmed to 2.1 A resolution using XPLOR
3 .8 and CNS l.O to a R-factor of 19.5% and R-free of 25.5%. Some of theinteresting features of this structure: 1) two flaps in this unliganded structure areclosed, 2) one water molecule hydrogen bonds to carboxyl groups of both Asp 25
and Asp 102 5, 3) the environment around the mutation site is not significantly
altered and 4) the main chain segment containing active site aspartyl residues
Asp 2 5 and Asp 1025 along with the bound water has moved by -0.5 A in a directionthat would render this side chain and the catalytic water more accessible to thesubstrate. This may explain why this mutant is more active during refolding step.
Email: mukeshk@apsara.barc.emet.in

A6-67SYN1HESIS OF N-NITRASO PIPERIDINE TIDOSEMICARBAZONE DERIVATIVES

N.Sampath and M.N.Ponnuswamy, Department of Crystallography
Biophysics, University of Madras. Guindy Campus, Chennai-600 025.

andN-substituted nitraso group in piperidine derivatives possesses high carcinogenic
activity in the biological system. A number of N-nitraso piperidine
thiosemicarbazone derivatives have been synthesized and the level ofcarcinogenicity depends on the substitution in various positions of the piperidine
ring. The derivatives are s)rnthesized by Mannich condensation reaction bydifferent amines, aldehydes and ketones at l: 2: l ratio. The second step of thereaction was carried out with 0.01 M of piperidine-4-one with equal mole ofnitrous acid in suitable condition. The product N-nitraso piperidine-4-one wasthen reacts with O.OlM of thisemicarbazide in alcohol medium. The white colour
solids obtained was crystallized in ethanol.
Email: nsampath75@yahoo.com

A6-68PRELIMINARY CRYSTALLISATION STUDIES ON OU1ER MEMBRANE PR01EIN C(OmpC)- LACTOFERRIN (Lf) COMPLEX.

SundaraBaalaji.N@.,
Arockiasamy.A@.,
Murthy.G.S".,
Singh.T.P#.,
Krishnaswamy.S@@Bioinformatics Centre, Dept.of.Genetic Engineering, School of
Biotechnology, Madurai Kamaraj University, Madurai-625 021,INDIA. *Primate
Research Laboratory, liSe. Bangalore-560 012,INDIA. #Dept.of. Biophysics, AliMS,
New Delhi-110 029,INDIA.
OmpC (Trimer, MW 120 kD) an immunologically important integral membraneprotein implicated in virulence of S. typhi is being crystallized in our lab.
Lactoferrin (Lf, MW 80 kD) an iron binding bacteriostatic protein is found to bind
specifically to OmpC from S. typhi and E. coli. Structural analysis of this · protein
complex will help to understand the mechanism by which Lf damages cell
membrane and exerts its antibacterial activity. Initial crystallisation trials(designed using CRYSTOOL program) on this protein complex were carried out
using Microdialysis, Vapour diffusion-Sitting Drop methods. Detergent
combination of Octyl PoE with C8 E 4 /C 8 HESO/C 12E 9 /OTG/OG /LDAO/ CYMAL5
at erne gave small plates, needle cluster and rod shaped crystals with precipitantcombinations of PEG 400/1000/1500/2000 and (NH 4 hS0 4 . Cationic additive
ammoniums, potassium, sodium, guanidium in combination with anions likenitrate, chloride, iodide, thiocyanate. tartarate were found to be promising. Theinteraction between these two proteins is clearly demonstrated on SDS-PAGE andprotein complex was recognised by anti-porin monoclonals in Western blot. SPRIA
studies show low percentage binding between OmpC and iodinated-Lf. Further
studies are being carried out to refine conditions for getting diffraction quality
crystals.
Email : sundara@mma. tn.nic.in

A6-69CRYSTAL STRUCTURE OF RIBOSOME RECYCLING FACTOR WI1H DIFFERENT
DE1ERGENTS FROM ESCHERICHIA COLI

N.K. Lokanath, Chun-Ai Wu, Jin Hee Jeong and Kyeong Kyu Kim, Protein
Crystallography Laboratory, Sungkyunkwan University, School of Medicine,
Suwon 440-746 , South Korea.
Ribosome recycling factor (RRF) is required for ribosome disassembly after thetermination of translation. RRF is an open L-shaped molecule composed of two
domains. Domain I has three alpha helices and the domain II consists of one
alpha helix and six beta strands . RRF is regarded as a good target for
antibacterial drug development, because it is essential for bacterial growth .
Inhibitors of RRF targeted to the contact region between RRF and its counterts
can be candidates for designing a novel compound with antibacterial activity. A
small molecule bound to the hydrophobic cleft may also inhibit RRF activity by
preventing the domain movement that could be important for the role of RRF.
Domain movements found in tRNA and EF-G have been suggested to be necessary
for their binding to the ribosomal A-site. Therefore we took up the task ofdetermining the crystal structure of RRF with different detergents. Five different
detergents which are confirmed to interact with RRF were used for crystallizationof complexes. Diffraction data from the complexes were collected at beamline
PL6B (Wavelength = 1.00875 Al using MacScience 2030b image plate detector atPohang Accelerator Laboratory. The data were processed and integrated by
DENZO and scaled by SCALEPACK in HKL program suite. The crystals belong to
the space group P3( 1)21. It is found that only one molecule is present in theasymmetric unit. The rigid body refinement followed by simulated annealing andtemperature refinement was performed with the program CNS. The analysis of theinteraction between detergents and residues in the cleft of RRF could be useful for
designing a novel compound as a RRF inhibitor.
Email : lokanath@med.skku .ac.kr

A6-70CRYSTAL S1RUCnJRES OF THE COMPLEXES OF L-ARGININE AND LlllSTIDINE WlTI:I GLUTARIC ACID AND A COMPARATIVE SIDDY OF AMINO
ACID-GLUTARIC ACID COMPLEXES.

N.T. Saraswathi, M. Vijayan, Molecular biophysics Unit, Indian Institute of
Science, Bangalore 560 012, India
X-ray analysis of crystalline complexes involving amino acids and peptides withcarboxylic acids, which are believed to have existed in the prebiotic milieu, hasserved to understand a variety of biomolecular interactions and aggregation
patterns. Complexes of glutaric acid with L-arginine and L-histidine (2 forms)
have been prepared and analysed. These three complexes exhibit different
stoichiometries and ionization states. Interestingly, and indeed surprisingly, thestructure of L-arginine hemiglutarate monohydrate is nearly identical to that of
DL-arginine acetate monohydrate and DL-arginine formate dihydrate. DL-arginine
succinate shares some important features with all the three arginine complexes.
The histidine ribbons in form I of the histidine complex are also found to occur in
L-histidine semisuccinate, again emphasising the relative invariance of someelementary patterns of amino acid aggregation. While the structures of the Larginine complex and form I of the L-histidine complex emphasize the relatively
invariant feautures of amino acid aggregation, form II of the histidine complex
illustrates their variability. The variability in the ionization state andstoichiometry observed in these and other amino acid-dicarboxylic acid complexes
appears to represent subtle differences in the response of a molecule to thepresence of another type of molecule in its neighbourhood. The change in thechirality of the component molecules in the complex could lead to drastic changes
in the aggregation pattern; alternatively, the effects of the change areaccommodated through small adjustments in essentially the same pattern.
Email: saras@mbu.iisc.ernet.in

AS-71S1RUCnJRAL SnJDIES ON Mycobacterium tuberculosis RECA COMPLEXED
WlTif ADP AND ATP-y-S.

S. Dattaa. N. Ganeshb, Nagasuma R. Chandrac, K. Muniyappab and M. Vijayana,aMolecular Biophysics Unit, hDepartment of Biochemistry and cBioinformatics
centre, Indian Institute of Science, Bangalore 560 012, India.
RecA protein plays a crucial role in homologou's recombination and repair ofDNA. All activities of the RecA protein require Mg+2 -ATP and single stranded
DNA. We have recently solved the crystal structures of RecA from M.tuberculosis
in its apo form as well as a complex with ADP-AlF4 . Analysis of these structures
revealed the expansion of the P-loop region in MtRecA compared to its homologue
in E.coli, which explained the reduced affinity of MtRecA for ATP. The bundle
formation was also found to be weaker in MtRecA, than in E.coli RecA, which
may have implications for recombination in mycobacteria. Here we report crystal
structures of MtRecA into which ADP was soaked and that of a co-crystallized
complex with ATP-y-S. Comparison of all the three ligand bound structures withthe apo MtRecA structure reveals the rigidity of the nucleotide binding pocket aswell as the interactions crucial for nucleotide binding. Unlike the consensus
residues of the P-loop, Glnl95, a residue of the DNA binding loop L2, shows
significant variation in conformation. In the ATP-y-S complex, the binding site of
the thiophosphate moiety is very close to the AlF4 moiety in MtRecA-ADP-AlF4
complex, confirming it to be the terminal phosphate binding site in the RecA
protein. The orientation of the nucleotide in all three ligand bound structures issimilar, implying that there is no major change in the mode of binding of ADP
andATP.
Email: nchandra@physics.iisc.ernet.in

A6-72

I.ACTOFERRIN - MELANIN INTERACTION AND ITS POSSffiLE IMPLICATIONS IN
MELANIN POLYMERIZATION: CRYSTAL STRUCTIJRE OF TIIE COMPLEXFORMED BE1WEEN MARE I.ACTOFERRIN AND MElANIN MONOMERS AT 2. 7 A
RESOLUTION

Nagendra Singh, Ashwani K. Shanna, and Tej P. Singh. Department ofBiophysics, All India Institute of Medical Sciences, New Delhi-11 0 029.
The concentration of melanin determines the intensity of colours of the skin andhair of animals. Melanin pigments are tyrosine-based polymers formed inmelanocytes within specialized organelles called melanosomes.
In order tounderstand the mechanism of melanin polymerization, lactoferrin, a basic proteinwith a pi value of 9 .0 was used to produce melanin. Lactoferrin is a monomericiron binding protein with a molecular weight of 80 kDa. The crystals of lactoferrin
were soaked in a solution containing dihydroxy phenylalanine (DOPA) andtyrosinase enzyme . These crystals were used for X-ray intensity data collection.
The intensity data were collected to 2. 7 A resolution to an overall completeness of
91% with an Rsym of 0.071. The crysta)s belong to orthorhom~ic space groupP2 12 12 1 with cell dimensions: a = 85.0A. b = 99.8A. c = 103.4A. The structure
was determined by molecular replacement method using the model of native marelactoferrin and refined to an R factor 0.215 (Rrree = 0.287) for all the data to 2.7A
resolution. The final model comprises 5281 protein atoms from 689 amino acids.
2Fe3+, 2C0 32 - ions , 2 Indole -5,6-quinone molecules (IQ) and 73 water molecules.
Two IQ molecules, one in each lobe bind to lactoferrin. In the C-lobe, the IQ bindsin the iron binding cleft whereas in the N-lobe, it is located in the side pocket
between two a.-helices which is filled with solvent molecules in the native ironsaturated mare lactoferrin. The IQ molecules interact with protein molecule
mainly through glutamic acid in both lobes without significant perturbation to theprotein structure. The orientation of N- and C-lobes in the present structure issimilar to that observed in the native iron saturated protein . However, as a resultof the binding of IQ molecules, the orientations of the domains N 1, N2 and C 1, C2
in the two cases differ slightly as compared to those observed in the native diferricprotein.
Email : nagendratomar@hotmail .com

A6-73PRELIMINARY X-RAY CRYSTALLOGRAPHY SIDDIESBINDING PROTEINOF ANOVEL PTKs

Ning Shil,2, Kaifu Tang2, Yu Gaol ,2 , Jian Jin2 , JianGang Yuan2, BoQin Qiang2& Zihe Raol · !.Laboratory of Structural Biology & ME Laboratory of Protein
Sciences, Tsinghua University, Beijing 100084, China. 2 . Institute of Basic
medicine science, Peking union medical school, Chinese Academic of medical
Science, Beijing, 100005 China.
We have identified a novel gene from screening the human eDNA library.
Sequence analysis suggests the protein encoded by this novel gene may belong to
a new adaptor protein family. Proteins of this family are known to interact with
PTKs. The overexpression of this protein decreases the growth rate in k562 cell,thus suggesting that it is related to cancer regulation and may be a regulator of
MAP kinase and cell proliferation.
Homology analysis showed PTKs binding domain of this protein is a key inunderstanding its function. It involves in the formation of a multimolecularsignaling complex in signal transduction. We cloned the PTKs binding domain of
this protein within GST vector. It was expressed as a GST fusion protein in E . coli
strain BL2l and isolated by glutathion-agarose affinity chromatography. The PTKs
binding domain protein was obtained by cleaving the eluted fusion protein withbovine thrombin and further purified by resource Q anion exchange and Gel
filtration Superdex G75 chromatography. The crystal was obtained by vapor
diffusion in hanging drops. Crystal grows to a typical size in about l day. The aimof our study is to elucidate the structure of the PTKs binding domain of thisprotein and to further understand its function by X-ray crystallography.

A6-74
NEW MECHANIC INSIGHTS REVEALED BY S1RUCTURE ANALYSIS OF TilE

DIOL DEHYDRATASE COBALAMIN COMPLEXES

Noritake Yasuokaa, Jun Masudaa, Naoki Shibataa, Yukio Morimotoa,b, , andTetsuo Torayac anepartment of Life Science, Himeji Institute of Technology,
Kouto 3-2-1, Kamigori, Ako-gun, Hyogo 678-1297, Japan, hrhe Harima Institute,
The Institute of Physical and Chemical Research, Kouto 1-1-1, Mikaduki, Hyogo
679-5148, Japan, andCDepartment of Bioscience and Biotechnology, Faculty ofEngineering, Okayama University, Tsushima-Naka, Okayama 700-8530, Japan
We have carried out the structural studies of dial dehydratase-cobalamincomplexes, and described the exact details of enzyme-coenzyme interaction of theadenine rrioiety. In the course of these studies, we also found that the electron
density corresponding to the cyano group of the enzyme-bound cyanocobalamin isalmost not observable at room temperature and very low even at cryogenic
temperature, suggesting its disscociation from the cobalt atom upon X-ray
On the contrary, the adenine moiety of the enzyme-boundirradiation.
adeninylpentylcobalamin was · clearly located in the map. When the enzymeadeninylpentylcobalamin complex was illuminated with visible light, the electron
density between the 5'-carbon . and cobalt atoms disappeared, and thetemperature factors of the atoms comprising the pentamethylene group becamemuch larger than those in the dark. This indicates the cobalt-carbon bondcleavage and suggests that the adenine moiety remains held by hydrogen bonds
with some residues in the enzyme. Thus, the formation of an adenine-anchoredradical upon illumination was demonstrated crystallographically with thiscomplex. These observations clearly indicate that homolysis of the cobalt-carbon
of alkylcobalamin takes place upon illumination with visible light but not readilycleaved during X-ray irradiation.
Email : yasuoka@sci.himeji-tech.ac.jp

A6-75HYDROGEN BONDING PATI'ERNS IN AMINOPYRIMIDINE - CARBOXYLATECOMPLEXES, AN OVERVIEW

P. Thomas Muthiah, J. Justin Robert, P. Prabakaran, S. Murugesan, V.
Sethuraman. P. Panneerselvam, S. Baskar Raj and N. Stanley.Department ofChemistry, Bharathidasan University, Tiruchirappalli- 620 024, India.
Hydrogen bonding patterns play vital roles in various biomolecular recognition
processes and interactions .
Aminopyrimidine-carboxylate interactions are
involved in Protein-nucleic acid recognition, enzyme-drug binding, etc. As simple
models for these interactions a number of aminopyrimidine-carboxylates havebeen investigated by X-rays in our laboratory (for examples Ref. l-3) . These
results will be presented along with some examples retrieved from the literature.
References:l. T. Balasubramaniam, P. Thomas Muthiah and W.T. Robinson, Bullet. Chem.
Soc. ojJapan, 69 (1996) 2919-2922.
2. P. Prabakaran et al, Acta Cryst. C57 (2001) 459-461.
3. P. Prabakaran et al, Acta Cryst. E57 (2001) o933-o936.
Email : tomm@bdu.ernet.in

A6-76HYDROGEN BONDING PATTERNS IN TRIMETHOPRIM SULPHATE TRIHYDRATE[(TMPH+h (S0 4 ) 2 -, TMPH+ = TRIMETHOPRIM CATION]

P. Thomas Muthiah, B . Umadevi, N. Stanley, X. Shui 1 and D. S. Eggleston 1 .
Department of Chemistry, Bharathidasan University, Tiruchirappa lli - 620 024,
India. 1SmithKlineBeecham Pharmaceuticals, King of Prussia, PA 19406, U.S .A.
Trimethoprim[2, 4-diamino-5- (3', 4', 5'-trimethoxybenzyl)pyrtmidineI
isanantibacterial agent. In its N 1-protonated form, it inhibits the bacterial DHFR
(dihydrofolate reductase) . The present study has been undertaken to explore theconformation and the hydrogen bonding patterns of trimethoprim in a variety ofmolecular environments . Hydrogen bonding patterns involving sulphate ion in
biological systems are of current interest 1 .
In this structure, twocrystallographically independent trimethoprim cations are paired through a pairof N2-H ... N3 hydrogen bonds. These pairs are further bridged by hydrogen bonds
involving water molecules and sulphate ions. The details of hydrogen bonding
networks and the conformation of the drug will be presented.

Reference:l. Akira Onoda, Yusuke Yamada, Mototsugu Doi, Taka-aki Okamura andNorikazu Ueyama, Inorg. Chem., 40 (2001) 516-521.

Email : tomm@bdu.ernet.in

A6-77
DISSECTING PROTEIN-PROTEIN RECOGNITION SITES

Pinak Chakrabarti 1 and Joel Janin2. 1 Department of Biochemistry. Bose InstituteP-1 I 12 CIT Scheme VIIM. Calcutta 700 054, India 2Laboratoire d'Enzymologie etde Biochimie Structurales CNRS UPR9063 91198, Gif-sur-Yvette, France
Protein-protein recognition sites in 70 complexes of krlown three-dimensional
structure are dissected in a set of surface patches by clustering atoms at the
12rotein-protein interface. In complexes where the interface buries less than 2000
A2 of protein surface, recognition sites usually form a single patch on the surfaceof each component protein, whereas larger interfaces are multi-patch. In multipatch interfaces, there is at least one pair of patches that are equivalent in size toa single-patch interface. Each recognition site. or patch within it, contains a coremade of buried interface atoms. surrounded by a rim of atoms that remain
accessible to solvent in the complex. The rim is similar to the rest of the protein
surface. but the core has a distinctive amino acid composition, which may help in
identifying potential protein recognition sites on single proteins of known
structures.
Email: pinak@boseinst.ernet.in

A6-78

PURIFICATION AND CRYSTALWGRAPifiC S'IUDIES ON A ClfiCKEN SERUM
1RANSFERRIN

Piyali Guha Thakurta, Rakhi Sengupta, Debi Choudhury And Sampa Biswas,
Crystallography and Molecular Biology Division, Saha Institute of Nuclear
Physics, lIM Bidhan nagar, Kolkata 700 064, India .

•Proteins of the transferrin family which include Serum transferrin, Ovotransferrin
and lactoferrin play a key role in controlling the levels of iron in the vertebratebody fluids. Serum transferrin specifically acts as an iron transporter, deliveringbound iron to target cells via receptor mediated endocytosis. Chicken Serumtransferrin from the blood Serum of ovulating white leghorn has been isolated andpurified in our laboratory and crystals of both the the apo- and holo- forms havebeen obtained. The former crystals belong to the tetragonal space group P43 2 12with unit cell parameters a=b=96.2, c=l80.2 A. From maps calculated using a
3.85 A cryo data set, the Ca. chain could be traced. Crystals of the holo- form were
found to belong to a primitive monoclinic space group with cell dimensions
a=73 . 1, b=59.2, c=84.0 A. y=97 .4 °. Preliminary X-ray analyses will be reported.
Email : piyali@cmb2.saha.ernet.in

A6-79S'IRUCTURALSTUDIESON
MODIFIED
ENDONUCLEASE A FROM E. coU K-12.

CYTOSINE

RESTRICTION

Tarn Deva, Preeti Mehta, Rakhi Rajan, V. Sujatha, Ranjan Prasad, R.Usha, K.
Dharrnalingam, S. Krishnaswamy. School of Biotechnology, Madurai Kamaraj
University, Madurai 625021, INDIA.
Modified cytosine restriction endonuclease A (McrA) (MW 31 kD) is encoded by thee14 prophage element found in E .coH K12 genome . The protein restricts entry ofT-even (gt) phages by restricting hydroxymethylated , non-glucosylated DNA. It
also cleaves DNA methylated by methylases like Hpall and Sssl. The protein isreported to be localised on the membrane.
We used the recombinant over expressed full-length (McrA31) protein; an Nterrninally modified construct (McrA29) and the N-terminal His tagged (McrA6H)
protein. The protein was purified using different column chromatography
techniques in each case. The protein was seen to form soluble oligomericaggregates, which do not disassociate even in the presence of Urea anddisassociate only in the presence of SDS. The C-terrninal region contains a HNH
motif identified as involved in DNA binding and contains 4 of the 7 cysteines in
the protein. A C-terminal deletion construct was made. However, this also showed
aggregation. There is a hydrophobic stretch in McrA in the N-terminal region. A
recombinant protein with the hydrophobic region deleted was constructed. Initialstudies on this protein suggest that this also tends to show similar oligomericaggregation. Circular dichroism studies suggest that McrA is a + fJ protein. The
structure shows high temperature stability. The fJ component of the structure isresistant to denaturation with 8M urea. Experiments with a.3 2 p labeled ATPsuggest that the protein bind ATP. Crystallization conditions were screened for
McrA using a Sparse Matrix screen using the sitting drop vapour diffusion
technique in crystal clear strips . The refined crystallisation conditions showed
improved crystal habit in the presence of ATP. The crystals obtained havecharacteristics similar to protein crystals. However, high-resolution diffraction
spots as from salt crystals dominate the diffraction pattern. The structural studies
and crystallisation trials of McrA will be reported.
Email: preeti@mma.tn.nic.in

A6-80STRUCTIJRAL INVESTIGATION OF la,3aDlliYDROXYAZADIRACHTOL ISOIA1ED
FROM NEEM KERNELS

aoepartment ofRajana, Geetha Gopalakrishnanb,
Malathia, S.S.
R.
Crystallography and Biophysics, University of Madras. Guindy campus, Chennai
600 025, India, and bSPIC Science Foundation, Guindy, Chennai 600 032, India.
Azadirachtins belong to a class of highly oxidised tetranortriterpenoids
characteristic of the genera Azadirachta and Melia. Among the azadirachtins ,Azadirachtin-A is the highly potent antifeedant even at low concentration against
over 200 agricultural pests and is also ecofriendly. One such azadirachtin,la,3adihydroxyazadirachtol was isolated from ethanolic extract of neem kernels.
The chemical structure was assigned based onlD and 2D NMR data. The
structure was unequivocally established by single crystal X-ray diffraction
studies. The compound was crystallized by hanging drop vapour diffusion
technique in P2 12 12 1 with cell parameters a=l4.142(6) A. b=l7.287(3) A,
c=2l.505(4) A. The structure was solved by SHELXS 97 and refined by SHELXL
97. The solution revealed two molecules in the asymmetric unit. The twomolecules were held together by hydrogen bonds and they differed predominantlyin the orientation of the functional groups attached to them . The relativeorientation of the two moieties namely decalin and dihyrofuranyl moiety, is similar
to that observed for azadirachtins H & I. The antifeedant activity of this compoundis 6 times that of Azadirachtin-A against 3rd instar larvae of Spodoptera Utura(tobacco cut worm). A comparative study with other azadirachtins will b e
presented .
Email: meetmali@yahoo.com

A6-81PURIFICATION, AND CHARACTERIZATION OF CATECHIN OXYGENASE FROMACINETOBACTER CALCOACETICUS

Sugadev, D. Balasundaresan, and M.N .Ponnuswamy. Department of
Crystallography and Biophysics. University of Madras. Guindy campus. Chennai600 025.

R.

Acinetobactor calcoaceticus is a bacterium that grows on the surface of liquids oftannery pits and tannery waste and oxidize tannin . An enzyme found in
Acinetobacter calcoaceticus cleaved catechin by oxygenation. The protein has
been expressed in Escherichia Coli and purified to homogeneity. The preliminary

characterization shows that the enzyme was active in a pH range 2 to 8 and at
50°C. Enzyme activity was maximum at pH 7.0. Further, the Km value of the
enzyme was 4 xl 0-7 moles per liter with catechin as substrate and the molecularweight was 4 7KDa.
Email : ragusugadev@yahoo.~omA6-82CRYSTAL AND MOLECULAR S1RUCTIJRE OF ~-[(1-PHENYL)-1-YLOXY]-a.-(1,1DIME1HYLETHYL)-1H-1,2,4 TRIAZOLE -1-E'IHANOL.
R.K. Tiwari and Sadhna Pandey·· SOS in Physics , Jiwaji University, Gwalior 474

011, India and •oepartment of Botany, Govt. Auto . Science College, Gwalior 474
009, India.
The Crystals of the title compound were grown from its solution in Toluene atroom temperature. The compound is a systemic fungicide and we are trying toestablish a relationship between the structure and its activity. The crystal data
are : C 10 H 16 N0 3 . a=7.8651(3)A , b = 13.1227(4) A, c = 15.1304(5) A,~=101.7550(10) 0 , P2Ifc , V = 1528.88(9) A3, Z= 4, ~ = 0 .082 , radiation used
MoKa.. The three- dimensional intensity data were collected on an Enraf-Nonius
CAD -4 diffractometer. The structure was solved by direct methods using
SHELXL-97 using full matrix least square refinement . Final R =5. 7% and wR=
8 .2% for 10655 observed reflections with I> 2.0a)1) . Molecules are held together
by Hydrogen bonds. The complete structural details will be presented .

Email : raunak@sancharnet.in

A6-83

CONFORMATIONAL CHAREC'IERiSTICS OF PEPTIDES CONTAINING GLYCYLRESIDUES: X-RAY CRYSTALLOGRAPHIC STIJDY AND CRYSTALLOGRAPHICDATABASE ANALYSIS.

Raghurama P. Hegde, N. Shamala, Department of Physics, Indian Institute of
Science, Bangalore 560012, India.
Structural studies of short oligopeptides and analysis on conformation of thesame oligopeptide sequences in protein structures leads to a better understandingof the relationship between amino acid sequences and polypeptide chain
conformation. This is very crucial in the de novo design of peptide mimics fordefined structural motifs. We present the crystal structure of the tripeptide Z-GlyGly-Val and analysis of the conformation of the tripeptide sequence in protein
structures and Gly-Gly segment in peptide structures. The tripeptide crystallizes
from CH 3 0H/H 2 0 mixture in the orthorhombic space group P2 12 12i with one
molecule in the asymmetric unit. The structure has been solved by direct methods
and refmed using least squares technique. The molecule takes an extended
conformation with antiparallel ~-sheet hydrogen bonding motif, in contrast to thetype III ~-tum conformation of unprotected Gly-Gly-Val, already reported. An
analysis of the conformations taken by Gly-Gly-Val segment in proteins, using
PDB , revealed that the glycines have a very high propensity for loops (72% and67.7% respectively for Gly(l) and Gly(2)) whereas the valine residue has almost
equal propensities for loops and ~-sheets (34.4% and 36.6% respectively) with
only a slightly less propensity for helices(25.8%) . Only in 12.9% of the cases are
all the three residues seen in helices. Our analysis of the peptide crystal
structures containing the Gly-Gly doublets taken from the CSD revealed that
conformation of the glycines are similar to those in proteins . Details of thestructure of Z-Gly-Gly-Val and the results of database analyses will be presented.
RPH thanks CSIR for SRF

Email : rph@physics.iisc.emet.in

A6-84

CRYSTAL STRUCTURE OF FIRST ACIDIC PHOSPHOLIPASE A2 FROM COBRA(Nqja nqja sagitti~ VENOM AT 2.1 A RESOLUTION

Rajendra Kumar Singh, Garima Singh, Sujata Sharma, Punit Kaur and Tej. P.
Singh, Department of Biophysics, All India Institute of Medical Sciences, New
Delhi-110029, India
Phospholipase A2 (PLA2 ) hydrolyzes the sn-2 ester of phospholipids, preferably inlamellar or micellar aggregates. PLA2 plays a part in a number of physiologicallyimportant cellular processes such as inflammation, blood platelet aggregation andacute hypersensitivity. These processes are all initiated by the release ofarachidonic acid from cell membrane, which is catalyzed by intracellular PLA2 s
and followed by conversion of arachidonic acid to prostaglandins, leukotrienes or
thromboxanes. An imbalance in the production of these compounds can lead tochronic inflammatory diseases such as rheumatoid arthritis and asthma.
Therefore structural information about PLA2s is necessary in the design oftherapeutic drugs. Here, we report the crystal structure of an acidic PLA2 from thevenom of Nqja nqja sagittifera (nns) . The purified PLA2 was crystallized by vapour
diffusion with a protein concentration of 2.5 mg/ml in 10 mM phosphate buffer
containing 40% ethanol. The crystals belong to tetragonal space group P4 1 with
a =b=42.8 A. c=65.8A. The structure has been refined to an R-factor of 0.192(Rrree=0.220). The structural features of acidic PLA2 corresponding to various
functional loop regions including the C-terminal fragment are very different fromof group I. It implies considerable function
those observed in other PLA2
differences between this and other group I PLA2s. Further datails will be
discussed.

Email: rajendra84@hotmail.com

A6-85CONSEQUENCES OF CHANGE OF CHIRALITY, ON TiiE ASSOCIATION OF
HELICES OF AN APOLAR HELICAL HAIRPIN MOTIF.

Rudresh 1 , Ramagopal.U.A4 , S.Ramakumarl.2, Dinkar SahaP, arid Virander S .
Chauhan3 , 1 Department of Physics, 2Bioinformatic Center, Indian Institute Of
Science. Barigalore -12. 3Jntemational Center For Genetic Engineering arid
Biotechnology, Aruna Asfa Ali marg, New Delhi-110067, India. 4 Brookhaven
National Laboratory, U.S.A.
Design of helical super secondary structural motifs is expected to provide
importarit scaffolds to incorporate functional sites, thus allowing the engineering ofnovel miniproteins with function. We have recently studied the helical hairpin
motif (PNAS, 98, 870-874, 2001). where we have observed that helices of opposite
handedness are associated through an extensive network of side-chain backbone
C-H/\0 interactions. In order to study the consequences of charige of chirality, on
the association of helices, we have replaced the D-Ala residues to L-Ala in thesequence
Acetyl-Gly-ilPhe-(D-Ala-ilPhe-ilPheh-D-Ala-(Gly) 4 -ilPhe-(L-Ala-L-LeuilPheh -L-Ala-NHMe. The peptide of length 21 residues was synthesized andcrystallized . The data collection was done at Brookhaven National Laboratory
U.S.A, using synchrotron radiation. The crystal belongs to monoclinic system.
Space group C2, with the unit cell parameters as a = 46.651A, b= 20.987A, c =14.449A and~= 94.662°. The structure solution was obtained by Direct Methods
using SnB (Shake and Bake) program. The R-factor at present stage of refinement
is 16.84%. All the residues including (Gly) 4 linker were clearly seen . The molecule
still folds into helix tum helix motif wherein both the helices are right handed 3 10
helices, but the nature of association is different from earlier. The two helices areassociated through the wedge into groove type. The (Gly) 4 flexible linker appears to ·be optimal for the association. The structure will be compared with that of theearlier HTH motif.
Email: rudresh@physics.iisc.emet.in

A6-86TOWARDS S1RUC1URAL S1UDIES ON COMPLEXES OFMEMBRANE PR01EIN OmpC WITH ANTIPORIN ANTIBODIES

1HE

OU1ER

Rukrnini.M .R. ®., Arockiasamy.A®., Anjali . A . KarandaeS , Murthy.G.S# ,Krishnaswamy.S® ®Bioinformatics Centre, Dept.of.Genetic Engineering, School of
Biotechnology, Madurai Kamaraj University, Madurai-625 021,INDIA. SDept. ofBiochemistry, liSe, Bangalore-560 012, INDIA #Primate Research Laboratory, liSe,
Bangalore-560 012,INDIA.
The homotrimeric (M.W. 120 kD} outer member protein OmpC from S.typhi is an
immunologically important porin. Large amounts of antibodies to porin are foundin the sera of patients with typhoid, caused by S.typhi. The structurally
homologous 16 stranded beta barrel trimeric porins primarily differ in the size
and nature of the loops. Structural studies and crystallisation of S. typhi OmpC
have been carried out earlier by our group . However, the crystal diffracted to low
resolution. Fab mediated co-crystallisation will help in increasing the polar
surfaces, which helps in better ordering of the lattice. Moreover, the structure of
the complex between Fab and porin will help the understanding the recognition
process.
Three monoclonal antibodies viz. MPN5 (IgG2b}, MP1 (IgG2a} which aresalmonella porin specific and P7D8 (IgG2a} Enterobacterial porin specific wereavailable for this study. The antibodies are purified using affinity chromatography
and ammonium sulfate precipitation followed by ion exchange chroma tography.
The purified antibodies were subjected to papain digestion and the Fab fragment
was obtained. The Fab fragments were used for the crystallisation screens.
Binding studies were also done by our group with the same antibodies to S. typhi
OmpC and found that P7D8 binding was stronger than MPN5. It was found that
MPN5 binds at a pH around · 5.0 and P7D8 around 9.0. The purification,
crystallisation of Fab and the binding studies of the two antibodies (MPN5 &P7D8} will be reported .
Email: rukmini@mrna.tn.nic.in

A6-87POLYPEPI'IDE CHAIN REVERSAL MEDIATED BY C-H···O HYDROGEN BONDS AT
HELIX TERMINI.

S. Aravindaa, Abhishek Bandyopadhyayb, P . Balaramb and N. Shamalaa,
aoepartment of Physics, Indian Institute of Science, Bangalore - 560012 , India,
bMolecuar Biophysics Unit, Indian Institute of Science, Bangalore -560012, India.
The site-specific insertion of 0 -amino acids into all L-peptide sequences provides
a convenient means for controlling polypeptide chain folding. The crystal
structures of two decapeptides containing two contiguous 0-amino acids arecompared . Peptide 1, Boc-Leu-Aib-Val-Ala-Leu-Aib-Val- 0Ala- 0 Leu-Aib-0Me [S.
Aravinda, N. Shamala, Animesh Pramanik, Chittaranjan Oas, P. Balaram (2000)
Biochem.Biophys.Res.Commun. 273, 933-936). and peptide 2 , Boc-Leu-Aib-ValGly-Leu -Aib-Val-DA1a~0Leu-Aib-0Me (this study) . Residues Leu(1) to Val(?) adopt
completely helical conformations. 0Ala(8) is the site of chiral reversal resulting inhelix termination by formation of a Schellman motif. ~esidues 9-10 adopt· nonhelical conformations. The extended conformation at 0 Leu(9) [<!> = +130°,\jJ =-160° for peptide 1, and <1> = +126° , \jJ = -156° for peptide 2) results in a compact
folded structure, stabilized by a potentially strong C-H ···O hydrogen bond between
Ala(4) c aH and 0 Leu(9) co in peptide 1, and Gly(4) c a H(2) and 0 Leu(9) co in
peptide 2 . The distance and angle parameters for C-H···O interaction are Ca···O =o3 .27A,
LCa-H-· ·0 =176°, and O·· ·Ha = 2 :29Ao in peptide 1, and Ca···0 = 3.59A , LC aH···O = 133°, and O···Ha = 2.86A in peptide 2. Inspection of the molecular. conforma tion of pep tides 1 and 2 reveals that chain reversal has been effectively
a chieved by the conformation adopted at the residues 8 and 9 , resulting in acompact fold.
This research is supported by a grant from the Council of Scientific and Industrial
Research , Government of India.
Email : saravind@physics.iisc.ernet.in

A6-88STRUCTIJRE AND HYDRATION OF TETRAGONAL LYSOZ\'ME GROWN IN THE
PRESENCE OF SUCROSE, SORBITOL AND TREHALOSE.

S.Datta, B.K. Biswal and M. Vijayan. Molecular Biophysics unit, Indian instituteof science, Bangalore 560 012, India.
Sugars and polyols are often used to enhance the stability of proteins.
Thermodynamic and physico-chemical studies indicate that the stabilising effectof these compounds is achieved by the modulation of the solvent structurearound the protein molecule. In order to elucidate the effect of the stabilising
additives on the structure of proteins and the associated ordered water moleculesin the hydration shell, the crystal structures of tetragonal lysozyme grown in thepresence of sucrose, sorbitol and trehalose have been refined. Also refined are thestructures of orthorhombic and monoclinic lysozyme grown under conditions inwhich tetragonal lysozyme is normally grown. A comparison of the two sets ofstructures with the structure of native tetragonal lysozyme reveals that the effectof the additives on the structure of the protein molecule is less than that of thenormal minor changes associated with differences in molecular packing. The
additives do not even affect the level of hydration as indicated by the numbers ofordered water molecules associated with the protein. Still more surprisingly, they
do not cause any significant reorganisation of water molecules in the hydration
shell. Thus it appears that the cause of the stabilising effect of the additives need
to be sought outside the immediate neighbourhood of the protein molecule.
Among the three additives, only one interacts with the protein in a coherent
manner. A sucrose molecule binds at the active site groove of the enzyme
molecule.
Email : mbusun@mbu.iisc.emet.in

A6-89CRYSTAL S1RUCTIJRE OF MIMOSINE REDUCED CYTOCHROME C FROMHORSE HEART

S. Deepthia, T. Santoshb, K Lalithab and Vasantha Pattabhia, aoepartment of
Crystallography and Biophysics, University of Madras, Guindy, Chennai 600 025,
India, and bDepartment of Chemistry, Indian Institute of Technology, Chennai,
India
Eukaryotic cytochrome c is an electron carrier protein found between the outerand inner membranes of mitochondria. The electron transfer occurs from
cytochrome reductase to cytochrome oxidase through cytochrome c. Cytochromec from horse heart, reduced by mimosine, a plant allelochemical has been
crystallized at 293K using hanging drop vapour diffusion technique. The crystal
diffracted up to 2.9A in P4 122 space group with cell parameters a= 73. 74, b=
73.74, c= 39.56A; Z=8. The structure was solved by molecular replacement usingoxidized cytochrome c without heme as search model. The 2F0 -Fc map calculated
without heme coordinates initially showed only one heme position. Refinement of
the structure showed the existence of a second heme position, which was parallelto the first one and the position of the mimosine molecule. With occupancies of
0.5 for both the heme positions and mimosine , the Rfactor and Rrree were reduced
to 0.30 and 0.43 respectively. The analysis of the structure reveals changes inconformation near the heme crevice where the heme has rotated approximately
90° from its original position and has occupied two alternate po·s itions. The
invariant residue Phe82 which is implicated in the reduction process ofcytochrome cis exposed to the external medium and has moved outwards against
the heme allowing the mimosine molecule to place itself in between the two heme
positions. Mimosine molecule interacts with the propionate sidechains of one of
the heme groups and Cys 14. The structure also explains the molecularmechanism of mimosine action and the electron transport mechanism.
Email: sdeep@joymail.com

A6-90ATOMIC RESOLUTION (l.l.A) STRUCTIJRE OF Plasmodium falciparum
TRIOSEPHOSPHATE ISOMERASE- 2 - PHOSPHOGLYCERATE,COMPLEX

S. Parthasarathy 1 , H. Balaram2, P. Balarml and M.R.N. Murthyh, !Molecular
Biophysics Unit, Indian Institute of Science , Bangalore 560 012, India and2Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore
560 064, India.
We have determined structures of various P. falciparum Triosephosphate
isomerase (PITIM) complexes in view of the importance of the enzyme as apotential chemotherapeutic target. The structural features at the active site andthe catalytic mechanism of the parasitic enzyme appear to be different from thoseof its homologues . Important substitutions found near the active site of PITIM are
Ser96Phe adjacent to catalytic electrophile His95, and Ala73-Phe74 by Ser73Tyr7 4 at the dim eric interface. The catalytic loop (residues 166-1 76) adopts the"open" conformation -in the structures of PITIM 3-phosphoglycerate and glycerol3-phosphate complexes. Crystals of PITIM-2-phosphoglycerate (2PG) complex
diffracted to 1. 1A resolution. Data were collected using X11 beam at DESY,
Hamburg. The structure was refined to an R factor of 13.7% using CNS_0.4 and
SHELX-97 programs. This represents the highest resolution structure for TIM
and reveals the active site geometry in great detail. As in other PITIM - substrateanalogue complexes, the catalytic loop adopts the "open" conformation in thiscase also. The crystal belongs to P2 1 space group and cont8.ins a mole_cular dimerin the asymmetric unit. Interestingly, 2PG had well defined density only in the B
subunit.
The density in the A subunit was broken and the pieces wereinterpreted as 2-oxoglycerate (20G) and meta phosphate ions (P0 3 ·). This is thefirst time a monomeric meta phosphate ion has been found in an enzyme activesite. Cleavage of 2PG could have occurred due to radiation or could be an
inherent property of PITIM.
Email : spartha@mbu.iisc.emet.in

A6-91STRUC'llJRES OF _Plasmodium falciparu.m 1RIOSEPHOSPHATE ISOMERASE
SUBS'IRATE ANALOGUE COMPLEXES: IMPLICATIONS FOR 'IHE DESIGN OF
ANTI-MALARIAL DRUGSS. Parthasarathy 1 , Hemalatha Balaram2, P. Balaram 1 and M.R.N. Murthyh,
1Molecular Biophysics Unit, Indian Instituteof Science, Bangalore 560 012 , Indiaand 2Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur,
Bangalore 560 064, India.
Protozoan parasites like Plasmodium falciparum (Pf) lack functional tricarboxylic
cycle and depend on glycolysis for energy requirement. Therefore, glycolytic
enzymes of these organisms are attractive targets for the design ofchemotheraphatic agents. The emergence and global spread of Ff resistant to antimalarial drugs necessitate the identification of new targets. The structure of Pf
Triosephosphate isomerase (PITIM) suggested that the replacement of a highly
conserved Ser at position 96 by Phe could be exploited for the) design of antimalarial drugs. We have determined the structures of two PITIM-Substrateanalogue complexes, (3-Phosphoglycerate (3PG) and Glycerol-3-phosphate (G3P))
with the view of obtaining further insights into the interactions involving Phe96.
The complexes belong to monoclinic P2 1 and contain a dimeric molecule in theasymmetric unit. The structures have been determined and refined at 2 .4A
resolution. The most intriguing observation is that the catalytic (flexible) loop
exists in the "open" conformation. This loop is known to move by about 7 A
towards the active site during catalyssis and as been observed in the "closed"
conformation in structures of TIM-ligand complexes from other sources.
Superposition of PITIM complexes with the corresponding complexes of
Trypanosoma cruzei TIM showed that the extensive steric clash that would occur
between the loop and Phe96, Ilel74 in the "closed" conformation of the catalytic
loop in PITIM prevents loop closure. Proximity between the C2-hydroxyl group of
the ligands and Phe96 indicates possible strategies that might be exploited for thedesign of anti-malarials.

Email: spartha@mbu.iisc.emet.in

A6-92

STRUCWRE OF Plasmodium falciparum TRIOSEPHOSPHATE ISOMERASE PHOSPHOGLYCOLATE COMPLEX IN 1WO DIFFERENT CRYSTAL FORMS:
IMPUCATIONSFORTHECATALYTICMEC~SMS. Parthasarathy 1 , H . Balaram2 , P. Balarrn 1 and M.R.N. Murthyh , 1'Molecular
Biophysics Unit, Indian Institute of Science, Bangalore 560 012, India and2 Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore
560 064, India.
Triosephosphate isomerase (TIM) catalyses the isomerization of dihyroxyacetone
phosphate (DHAP) and D-glyceraldehyde-3-phosphate (D-GAP) and is thought tobe an evolutionarily perfect enzyme. The structural aspects of its catalytic
mechanism are well characterized using a variety of techniques. The reaction
intermediate, cis-enediol (diolate), is highly reactive and can undergo rapid
phosphate elimination to form cytotoxic methlyglyoxal. This is prevented by a 7 A
movement of the catalytic (flexible) loop, comprising of residues 166-176, towards
the active site sequestering and binding the intermediate in a conformation that is
not suitable for phosphate elimination. The catalytic loop has usually been
observed in the "closed" conformation in TIM-ligand structures. In the
Plasmodiumjalciparum (Pf) TIM-Substrate analogue complexes, the catalytic loop
adopts the "open" conformation, suggesting that the replacement of conserved
Ser96 by Phe in Pf could profoundly influence the catalytic mechanism. The
structure of Phosphoglcycolate (PG , a transition state analogue) was determined
to gain insights into the contrasting features of catalysis 6 PITIM and its
homologues . PITIM-PG complex crystallized in both orthorhombic (P2 12 12tl andmonoclinic (C2) forms and diffracted to 2.8 and l.9A resolution, respectively. The
P2 12 12 1 form contains two dimers in the asymmetric unit while the C2 form has
only a monomer in the asymmetric unit. In contrast to other PITIM substrateanalogue complexes and P2 12 12 1 form of PG complex, the catalytic loop adopts
the "closed" conformation in the C2 form. The closed conformation is achieved byforcing the residues Phe96 and Leu167 into alternative conformations .
Implications of these structural results to TIM catalysis are discussed .

Email : spartha@mbu.iisc.emet.in

A6-93

CRYSTAL S1RUCTURE OF TGCGCA AT 1.6A RESOLUTION

S. Thiyagarajan, P. Satheesh Kumar, S.S. Rajan and N. Gautham, Departmentof Crystallography and Biophysics, University of Madras, Chennai 600 025. India.
It is known that the altemating copolymer d(CG)n. when exposed to high salt or
ethanol concentration, adopts a left handed helical structure, namely Z-DNA. In
our program to study the effect of AT base pairs in such structures, we haveearlier studied and reported the micro heterogeneity in the structure of canonical
Z-DNA sequence d(CGCGCG) that occurs when AT base pairs are introduced into
the sequence at different positions viz., d(CACGCG).d(CGCGTG) andd(CGCACG).d(CGTGCG). To study the effect of AT base pairs at the terminals of
the sequence. we are working on the crystal structures of d(CGCGCA) .d(TGCGCG)
and d(TGCGCAh- Here we report the room temperature X-ray crystal structure ofd(TGCGCAh refined at l.6A resolution. The crystal belongs to the space groupP2 12 12 1 with unit cell parameters a=2l.18A, b=28 .36A and c=44.44A. The overall
structure of the sequence falls in the category of Z DNA. The refinement
converged to an R value of 21.3% (Rrree = 27.9%) for 3445 reflections between
19.0A and l.6A. Comparison of the present structure with that of the same
sequence at low temperature (120K) reported earlier (Harper et al, 1998 Acta
Cryst. D54, 1273.) showed that the present structure is larger by 0.22A along theaxis of the Z-DNA than the low temperature structure, but the value of rise at thevirtual step between the symmetry related duplexes is less in the present
structure. The base step and base pair parameters at the terminals show
significant variation from the low temperature structure due to the flexibility ofthe terminal AT base pairs at higher temperature. However, comparisons of thestructures at the two different temperatures with others in the database showthat the effect of sequence on the structural features is greater than the effect oftemperature.

Email: tyahaa@yahoo.com

AB-94

S1RUCTURES OF TWO COMPLEXES OF PRO'IEINASE K WITH DESIGNEDPEPIIDES (I)Pro-Ala-Pro-Phe-ru\la-Ser-Ala AND (II)Pro-Ala-Pro-Phe-ru\la-Ala-Ala
AT ATOMIC RESOLUTIONS.

Sameeta Bilgrami 1 , Vikas Chandral, Punit Kauri, Christian Betzel2, and T . P.
Singh l. 1Department of Biophysics, All India Institute of Medical Sciences, New
Delhi-110029, India. 2Institute of Medical Biochemistry and Molecular Biology,
UKE. C/0 DESY Notkrestrasse 85, 22603, Hamburg, Germany.
Serine proteases are found in all organisms, functioning in digestion , posttranslational processing, processing of secreted proteins, neurotransmitters andhormones, blood coagulation and complement fixation . These are therefore,
attractive targets for specific drug design in pathological conditions. The
approaches of structure-based drug design through evaluation of the interactions
formed between the enzyme and designed peptides are logical steps. We report
here the crystal structures of two complexes formed between proteinase K andthe two designed peptides at 1.0 A resolution. The intensity data on the complexes
were collected with synchroton beamlines at DESY. The unique reflections for the
first complex were 119,145 whereas in the second structure the unique reflections
were 101.462. Both the structures have an overall completeness of more than
99%. Both the structures were refined to R-factors of 11 .5% and 12.0%
respectively. In both the structures, hydrogen atoms appear as significant peaksin the F 0 -Fc difference electron density maps and carbon, nitrogen and oxygen
atoms can be differentiated. The estimated standard deviations for all main chain
non-hydrogen atoms are 0.011(0.013)A in bond lengths and 0.6°(0.7°) in bondangles. Hydrogen bonds are resolved in the serine protease catalytic triad (SerHis-Asp) and in the complex with the peptides. The density for the peptide atoms
is clearly observed . More than 450 water molecules were identified from thedifference Fourier maps.
Email : sameeta_b@hotmail.com

A6-95

S1RUCTIJRAL COMPARISON OF A FEW THIOL PR01EASES

Chandana Chakrabarti, Sampa Biswas and J.K. Dattagupta, Crystallography andMolecular Biology Division, Saha Institute of Nuclear Physics, 1 I Af Bidhan Nagar,
Kolkata 700 064, India.
Ervatamia Coronaria, a flowering plant indigenous to India, is known to havemedicinal importance and other applications. Ervatamin B (26kd) which is ahighly stable Cysteine protease has been isolated and purified from the latex ofthis plant. It exhibits some novel properties distinctly different from papain andother cysteine proteases, though it probably shares an ancestral gene with that ofpapain. The structure has been solved at high resolution (1.63 A) and thestability of the protein has been studied from a structural point of view. A uniquesubstrate specificity of the enzyme could also be explained from its three
dimensional structure. Amino acid sequence of the protein has also been
determined using Crystallography.
Email : Sampa@cmb2.saha.ernet.in

A6-96

S1RUCTURE AND FUNCTION OF HUMAN HEMATOPOIETIC PROSTAGlANDIN DSYNTHASE ACTIVATED BY MAGNESIUM ION

Shigehiro Kinugasa 1 , Tsuyoshi Inoue 1 , Yousuke Okano 1 , Hiroyoshi Matsumura 1 ,Yasushi Kai 1 , Daisuke Irikura 2, Osamu Hayaishi 2, Masaki Yamamoto3, Takashi
Kumasaka3, Masashi Miyano3, Yoshihiro Urade2 (!Graduate School ofEngineering, Osaka University; 20saka Bioscience Institute; 3RIKEN Harima).
Prostaglandin D 2 (PGD 2) is responsible for the symptoms seen in mastocytosis
patients, such as flushing, diarrhea, tachycardia, dyspnea, and deep sleep.
Especially PGD 2 released from mast cells is an allergic and inflammatory
mediator, as demonstrated an allergic asthma model with the PGD receptor genedisrupted mice. The structure of the prostaglandin D synthase (PGDS) is a potent
target for the anti-allergic drug design.
We have determined the 1.8 A X-ray structure of human hematopoietic PGDS,
which catalyzes the production of an allergic mediator, PGD 2, in the presence ofglutathione. A metal binding site of Mg 2+ or Ca2+ has been identified at the dimer
interface clustered by six aspartates, Asp93, Asp96 and Asp97 and thosecorresponding residues in the counterpart of the dimer.
The Mg2+-bound form displays the remarkable change of metal coordination
structure from the Ca2+-bound form. The rearrangement of the hydrogen bond
network has also occurred. The interaction between Asp96 and the Mg 2+ ion is
expected to strengthen the structure and that with Argl4 leads to a certain degreeof rotation. The rotated Argl4 could hydrogen bond to glutathione and Mg2+
extremely improves the Km value for glutathione.
In this work we're discussing the novel reaction mechanism with the Mg2+-boundstructure.
Email : kinusan@chem.eng.osaka-u.ac.jp

A6-97

CRYSTAL STRUCnJRE OF TTR INSIGHTS INTO ITS MECHANISM AS AN

ACETYLTRANSFERASEHe H., DingY., Sun F., Bartlam M., Zhang R., Duke N., Joachimiak A., Cao Z. ,Shao Y., Li X., LeY., Jiang F. , Liu Y. , Tang H .. Wang Y., Liu J., Zhao N., Rao Z.
Tabtoxin Resistance protein (TIR) is an enzyme endowing Tabtoxin-producing
pathogens, Pseudomonas syringae pv. Tabaci, resistance to their toxins. The
crystal structure of TIR complexed with AcCoA was determined at l. 55 A
resolution by MAD method. The structure resembles a letter V, with an AcCoA
inserting between the two arms. The natural binding of AcCoA to TIR in vivo aswell as the structural homology of TIR to the proteins belonging to the GCN5Related N-acetyltransferase (GNAT) superfamily confirm TIR as a member of thesuperfamily. The high resolution structural data supports a facile single-stepa cetyl-transfer catalytic mechanism and a reasonable self-protection mode ofpathogen from its toxin. Furthermore, as a member of GNAT superfamily, thestructure of TIR sheds light on the catalytic mechanism of some proteins withbiologically significant role in the superfamily, especially in understanding theimportant role of the conserved residue Tyr equivalent to Tyrl4lofTIR.

A6-98

THERMOPHILUS
LIPOAMIDE
CRYSTAL
STRUCIDREOF
THERMUSDEHYDROGENASE (L-PROTEIN) OF THE GLYCINE DECARBO~E
MULTIENZYME SYSTEM.

T. Nakai, J. Ishijima, S. Kuramitsu, N. Kamiya, RIKEN Harima Institute I SPringB. 1-1-1 Kouto, Mikazuki, Sayo-gun, Hyogo 679-5148, JAPAN.
The glycine decarboxylase complex (GDC) consists of four different component
enzymes (P-, H-. T- and L-proteins). In order to determine the structure of GDC ,all the component enzymes of Thermus thermophilus GDC were cloned andoverexpressed in Escherichia coli. Crystallization conditions for the purified
components were separately screened. To date, L- and H-proteins have been
crystallized and the structure of L-protein has been solved. In this meeting, wereport the crystal structure of L-protein and a new method of co-expressing two
subunits of P-protein to fold into its n ative structure.
The struct ure of L-protein (lipoamide dehydrogenase; EC 1.8. 1.4) was solved bymolecular replacement method. The final value of crystallographic R-factor afterrefinement was 22 .9% at 2 .8 A resolution with good geometry of the fina l model.
The enzyme has two identical subunits related by a non-crystallographic twofold
axis. The tertiary structure is similar to those of yeast, pea and other prokaryotic
enzymes. The active site, consisting of FAD, Cys47, and Cys52 from one subunitand His446' from the other, is highly conserved. In order to understand thesubstrate recognition mechanism of this enzyme, the screening of crystallization
conditions for the L-protein in complex with substrate is now in progress.
Email: nakaix@spring8.or.jp

A6-99TIIE CRYSTAL STRUCTIJRES OF CYI'OCHROME C FROM HORSE, BOVINE AND
TIJNA: TIIE EFFECT OF NITRA'IE IONS IN THE PACKING

T. Yamanea, J. Nodaa, T. Shiraia, T. Kubotab, K. Hommab and M. Atakab,
aoepartment of Biotechnology and Biomaterial Chemistry, Nagoya University,
Nagoya 464-8603 , Japan, and bNational Institute of Bioscience and Human
Technology, Tsukuba 305-8566, Japan.
Tuna ferricytochrome c was crystallized using two salts, ammonium sulfate (AS)and NaN0 3, as precipitants (1). while horse ferricytochrome c was crystallizedusing AS and NaCl (2) . Ataka et al. have succeeded in growing crystals ofcytochrome c from horse, bovine, tuna and yeast, using AS and NaN0 3 asprecipitants, and suggested the importance of N0 3- ion for the crystal growth (3).
In order to examine the role of N0 3- ion in the crystallization process, X-ray
structure analyses of horse, bovine and tuna cytochrome c's were carried out at
2.1 A, 2 .35 A and 1.8 A resolution, respectively.
Crystallization conditions: for horse and bovine, hanging-drop method, 0.52 gAS
and 0 .18 g NaN0 3 were dissolved into 1 ml of 0.05M ammonium phosphate buffer(pH 6 .0) for the reservoir solution; for tuna, batch method, 0.35 g AS and 0 .10 g
NaN03 were dissolved into 1 ml of the buffer.
The trigonal crystals of horse protein (P3 1 , a=80.75, c=90.85 A) and bovine protein(P3z, a=85. 1, c=88.5 A) contain 6 molecules per asymmetric unit, respectively. In
the horse crystal, there were 2.5 N0 3- ions per cytochrome c molecule. The
packing scheme in the horse crystal suggests that Asn 103 played an importantrole in the formation of the lattice by interacting with one of the N0 3- ions , in spiteof the disappearance of the corresponding N0 3- ion in the bovine crystal. The
tetragonal crystals of tuna protein (P4 3, a=75.00, c=36 .68 A) were isomorphous to
the type B crystals (1). and contain 1.5 N0 3- ions per cytochrome c molecule.
1) R. Swanson et al. (1977) J . Biol. Chem. 252 , 759-775.
2) G. W. Bushnell et al. (1990) J. Mol. Mol. 214, 585-595.
3) T. Kubota et al. (2001) J . Crystal Growth, in press .
Email : yamane@hix.nagoya-u.ac.jp

A6-100

S'IRUCTURAL STUDIES ON COBRA VENOM FACTOR

Talat Jabeena, Sujata Shannaa, R. K. Singha, Christian Betzelb, and T. P. Singha.
8
Department of Biophysics, All India Institute of Medical Sciences, New Delhi
110029, India, bJnstitute of Medical Biochemistry and Molecular Biology,
University of Hamburg c/o DESY, Notkestrasse 85, 22603 Hamburg, Germany
Cobra venom factor (CVF} is the complement-activating protein in cobra venom. It
is a three-chain glycoprotein with a molecular weight of 149 kDa. In serum, CVF
forms a bimolecular enzyme with the Bb subunit of factor B. The enzyme cleaves
C3 and C5, causing complement consumption in human and mammalian serum.
CVF is frequently used to decomplement serum to investigate the biological
functions of complement and serves as a tool to investigate the multifunctionalityof C3. Furthermore, CVF bears the potential for clinical applications to deplete
complement in situations where complement activation is involved in thepathogenesis of disease. CVF was isolated from Indian cobra (Naja naja sagittifera}
venom. The protein was crystallized at room temperature using the sitting drop
vapour diffusion method. The crystals diffract to 2.7 A resolution and belong to
the tetragonal space group P4 1 with unit-cell dimensions a = b = 62.7 A and c =368.1 A. As no similar structure is available in the database, several heavy atom
derivatives have been prepared. The structure analysis is posing problems but
further efforts are underway. The unique features of the structure and the
problems encountered will be discussed.
Email: talat_jabeen@yahoo.com

A6-101

CRYSTAlLIZATION AND PRELIMINARY X-RAY ANALYSIS OF MAIZE GLUTAMINESYNTHETASE

Tatsuya Uchidaa, Genji Kurisua, Hajime Sugawarab, Masami KusunokP,
Toshiharu Hasea and Hitoshi Sakakibarab, arnstitute for Protein Research, Osaka
University, Suita, Osaka 565-0871, Japan. and bPlant Science Center, RIKEN,
Hirosawa 2-1, Wako , Saitama, 351-0198, Japan.
Glutamine synthetase (GS) is a key enzyme in the assimilation pathway forammonium. It catalyzes the formation of glutamine from ammonium andglutamate using adenosine triphosphate. Especially in higher plants , glutamine isan organic nitrogen donor in amino acid biosynthesis and GS plays an importantrole. Bacterial GS, which has been widely studied structurally, is usuallycomposed of 12 subunits . Eukariotic GS comprises 8 subunits and its three
dimensional structure remains still unknown . The crystal structure of thisenzyme from maize (Zea mays) will be essential for understanding themechanisms of fixation of ammonium in eukaryote, and we started the
crystallographic work of maize GS. Recombinant maize GS was overexpressed in
E. coli and purified. Crystallization was performed by the hanging-drop vapor
diffusion method using PEG 8000 as a precipitant. Crystals of GS appears at 20
oc within two weeks and belong to the monoclinic space group P2 with unit-cellparameters a= 109 .6, b = 186.6, c = 180.0 A. (3 = 101.5°. A native data set wascollected to 3.0 A resolution on a Cu Ka rotating-anode X-ray source. The
Matthew's coefficient is 2.9 A3 /Da, corresponding to two octamers with a total
molecular mass of 640 kDa in the asymmetric unit.
Email : tat-u@protein.osaka-u.ac.jp

A6-102
S1RUCnJRE DE1ERMINATION OF 1HE ORF7 NUCLEOCAPSID PR01EIN OF
PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS (PRRSV)Tommy Wang, Danny Doan and Terje Oakland , Institute of Molecular Agrobiology,
The National University of Singapore, Singapore 117604.
Porcine reproductive and respiratory syndrome virus (PRRSV) is a widespread,highly infectious and economically important virus of pigs. It belongs to theArteriviridae family and has a single-stranded positive-sense RNA genome. The
virion contains an isometric nucleocapsid core comprised of the orf7 geneproduct, surrounded by a lipid envelope containing a number of membraneproteins which are the gene products of orf2-6. The orf7 nucleocapsid protein has
123 amino acids and contains a highly positively charged and flexible N terminus,
which presumably binds the RNA genome.
We have cloned, expressed and crystallized, a 6xHis-tagged , truncated form of theorf7 protein, referred to Orf7 .2, which containing the C-terminal 63 amino acidsof Orf7. Orf7 .2 crystallizes in the P3 121 spacegroup with a=44.5A, c=125.1A, andcontains a dimer in the asymmetric unit. We have s olved the structure of Orf7.2
to 2.5A resolution using MIR with two derivatives, K2 Pt(CN) 4 and KAuCl4.
Preliminary analysis of the solvent-flattened map shows the protein dimers whichappear to have a predominantly f)-sheet structure.
Email : dokland@ima.org.sg

A6-103

PRELIMINARY CRYSTALLOGRAPifiC S1lJDY OF CALCIUM/CALMODULIN DEPENDENT PROTEIN KINASES a. FROM RAT CEREBRAL CORTEX

Toru Hanamura, Makoto Nakabayashi, Naoki Shibata, Yukio Morimoto and
Noritake Yasuoka Department of Life Science, Himeji Institute of Technology, Koto
3-2-1, Kamigori, Ako, Hyogo 678-1297, Japan
Three multifunctional calcium/calmodulin-dependent protein kinases (CaMkinases). CaM kinase I, CaM kinase II and CaM kinase N, are reported to play
important roles in controlling a variety of neuronal functions in response to anincrease in intracellular Ca2+ concentration. Among three kinases, CaM kinase I
and N are activated by CaM kinase kinases (CaMKKs).
One of CaMKKs, CaMKKcx is known to phosphatize Thr196 of CaM kinase Nand
activate it in nerve cell nucleus after binding Ca2+-calmodulin. In the present .
study, recombinant CaMKKo: from a rat cerebral cortex eDNA clone was expressedin Escherichia coli and was purified by the procedures including Calmodulin
Sepharose affinity chromatography [Kitani, T., Okuno, S . and Fujisawa, H . (1997)
J . Biochem. 121, 804-810]. This purified enzyme gave one major protein bandcorresponding to a molecular weight of about 66k upon SDS-PAGE, although the
enzyme was a molecular weight of about 56k calculated from its amino acidsequence. It is necessary to investigate the structure of CaMKKcx in order to know
the physiological functions , the molecular mechanisms, and the reactions withligands. From this aspect, we start to screen the crystallization conditions in orderto solve the structure by means of X-rays. We wish to report a preliminary
crystallographic study of CaMKKo:.
Email: camkk@livedoor.com

A6-104

STRUCWRE
CRYSTAL
Trichosporon pen.icillatum

OF

POLYME1HOXYGAIACWRONASE

FROMToshiji Tada a. Chao-Tsang Lu b, Talmo Sakai c and Keiichiro Nishimura a. a
Research Institute for Advanced Science and Technology, Osaka Prefecture
University, Sakai, Osaka 599-8570, Japan, b Institute of Botany. Academia
Sinica, Nankang, Taipei, Taiwan 11529, Republic of China and c Department ofFood Science, Kinki University, Nakamachi, Nara 631-8505, Japan
Pectic substances are acid polysaccharides of high molecular weight that arewidespread in the plant kingdom. Polymethoxygalacturonases (PMGs) catalyze
the hydrolysis of <X-1 .4-glycosidic linkages in the methoxylated polygalacturonate
which is a component of pectic substances. We have initiated an a nalysis for the
crystal structure of PMG from Trichosporon peniciHatum to elucidate therecognition mechanism of the substrate. The enzyme, consisting of 334 residues ,was crystallized using PEG 1000 as a precipitant. The crystal belongs tomonoclinic, space group C2 with unit cell parameters of a= 165.6, b = 61.0, c =48 .7 A. f3 = 93.1°. A native data set from a crystal was collected to 2 . 1 A
resolution at room temperature on a Rigaku R-AXIS Ilc imaging-plate systemusing Cu Ka radiation. A total of 106223 observed reflections were scaled andreduced to yield a data set containing 28168 unique reflections with an Rmerge of
7.6%. Molecular replacement calculations were carried out with the program
AMoRe using endopolygalacturonase II from Aspergillus niger as a starting model.
The best solution had a correlation coefficient of 0.599 and an R-factor of0.434.
The refinements including solvent molecules are now in progress.
Email: tada@riast.osakafu-u.ac.jp

A6-105
CRYSTALS'IRUCTURE
OF
DECAMERICE.
coli
KETOPANTOATEHYDROXYMETHYLTRANSFERASE BY MAD PHASING WITII 160 Se-Met SITESFrank von Delft 1 , Tsuyoshi Inoue 1 ·*, Adrian Saldanha2 , Chris Abeli2, Alison G.
Smith3, and Tom L. Blundelii(lDep. of Biochemistry, Univ. of Cambridge, 2Dep. of
Chemistry, Univ. of Cambridge, 2Dep. of Plant Sciences, University of Cambridge)*Present address: 1Grad . Sch. of Engineering, Osaka Univ.
Ketopantoate hydroxymethyltransferase (KPHMT) catalyzes the first committed
step in the biosynthesis of coenzyme A (CoA), namely conversion of aketoisovalerate (a-KIVA) to ketopantoate (3,3-dimethyl-2-oxobutanoate). Here, wereport the crystal structure of decameric KPHMT from E. coli bound to product,ketopantoate 9-nd determined to 1.8 A resolution, through the use ofmultiwavelength anomalous dispersion (MAD) with 160 selenomethionine (SeMet)sites. This number is the largest structure to date that has been solved by MAD.
Ketopantoate is shown to bind to a magnesium ion through its keto and carboxylgroups. Similar binding for the substrate, a-KIVA, is believed to orient andactivate the C3 position for deprotonation and subsequent nucleophilic attack.
Additionally, we propose a mode of binding for the cofactor, N5, N 10methylenetetrahydrofolate (5, 10-CH2-H 4 folate).

Email : inouet@chem.eng.osaka-u.ac.jp

A6-106
2-CARBETIIOXY-3-AMIN0-4-(4-METIIYLPHENYL)-6-PHENYL

FUR0[2,3-B]

PYRIDINE - A NOVEL FUROPYRIDINE

U. H. Patela , C.G.Daveb , M. M. Jotania, H. C. Shahh, aoepartment of Physics,
Sardar Patel University, Vallabh Vidyanagar-388120,Gujarat,India, hOrganic
Syntheses Laboratory, M.G. Science Institute, Navrangpura, Ahmedabad380009, Gujarat,India.
Furopyridines consists of .n-excessive furan ring and .n-deficient pyridine ringwhich are of interest to study the annelation perturbing electronic structure
which is manifested on reactivity of substances. These group of compounds also
play an important role in many biologically active substances. We report,
therefore, crystal and molecular structure of 2-carbethoxy-3-amino-4-(4methylphenyl)-6-phenyl furo[2,3-b]pyridine. Crystals of title compound areorthorhombic having space group Pbca obtained from methanol solution by slow
evaporation method. Crystal parameters are: a = 7.755(3). b = 21.231(6). c =23.020(7) A, Z = 8, V = 3790(2) A3, Pc = 1.303 Mg m -3 , fJ- = 0.183 mm-1 .Finalresidual index is 0 .043 for 2466 unique reflections. Furan ring is non-coplanarand best plane of it is almost coplanar having dihedral angle of 2 .42(12) 0 withpyridine ring plane . Sterle interactions forces the phenyl rings away from thepyridine ring plane by 45 .34(1) 0 and 18.57(1) 0 respectively. The structure ismainly stabilized due to weak van der Waal forces as no hydrogen bond isobserved.

Email : uhp@spu.ernet.in

A6-107

BIMETAL COMPLEX OF A NUCLEOTIDE: STRUCTIJRE OF SODIUM-POTASSIUM
SALT OF CYTOSINE-5'-MONOPHOSPHATE HEXAHYDRATE METIIANOLSOLVATE

Umesh Prasad Singh and T. P. Seshadri, Department of Physics, Indian Instituteof Science, Bangalore 560012, India.
Bimetallic Sodium-Potassium complex of Cytosine-5'-Monophosphate, [(C 9 H 12 N3
Os P 2 -).(l.25 Na+).( 0. 75 K+).(5. 75 H 2 0).(0.5 CH 3 0H)) crystallizes in the monoclinic
space group P2 1 with cell dimensions a= 8.869(2), b = 20.580(6), c = 23.179(1) A,~ = 105.791(1 (, Z = 2, V = 4070.9(13) A3 with four molecules in the asymmetricunit. The MoKa intensity data at 213 K consisted of 16,184 unique reflections.
Final R = 8.09 %. All the four molecules in the asymmetric unit show anti
conformation about the glycosidic bond, C2'-endo sugar puckering and gauchegauche (g+) conformation about the exocyclic C4' - C5' bond. There are someconformational differences between this structure and other 5'-CMP and 5 '-dCMP
structures reported earlier. The K+ ions coordinate with base, ribose, phosphate
and water oxygens besides the base nitrogen. The Na+ ions, however, do not bindto the base oxygen. The cytosine bases show alternate base-base and base-ribose
04' stacking along the c-axis with Na+ and K+ ions forming channels between
them parallel to the molecular columns.

Email: ume~h@physics.iisc .emet.in

A6-108
4- AMINO - N (2 -QUINOXALINYL) BENZENE - SULFONAMIDE, C14 H12N4 02S

Urmila H .Patel , Mahendra B. Gorkh , Rajesh D. Modh , Bharat D. Patel, Pinal D.
patel. Department of Physics, Sardar Patel University. VallabhVidhyanagar
388120, Gujarat India.
Sulfaquinoxalinyl, 4 - amino - N - (2 - quinoxalinyl) benzene - sulfonamides,
C 14H 12N 4 0 2S is a well-known member of antimicrobial sulfonamide family. It is apotent antitumor drug. Its chlorine substituted derivative shown in vitro
antitumor activities against human lungs . Transparent tiny single crystals of thetitle compound are obtained from· the mixture of acetonitrile and methanol in thepresence of few drops of ethyl acetate. It crystallizes in monoclinic space group
P21 /a with Z=8 . Crystal data are a= 15.627(10), b = 6.183(17), c = 28.949(9) A, P
= 103.87 °, Dm = 1.469Mgm-3. SHELX-97 program is used to solve and refine thestructure. There are two molecules in the asymmetric unit. Geometry aroundsulfur i~ as usual a distorted tetrahedron . Quinoxaline part of both the molecules
are planar. Phenyl ring of sulfonyl moiety of mole A makes an angle of 78.99° tothe quinoxaline system whereas the angle is 78.91° for mole. B. The conformation
is 'CIS' for mole. A and mole. B with respect to S-N bond . Extensive hydrc~genbonds both intra & inter stabilized the structure. Hydrogen bonding network will
be discussed in detail.
Email : uhp@ spu.emet.in

A6-109

THE STRUCTURE OF THE RIPPLE PHASE OF SOME PHOSPHOLIPID BllAYERS

Kheya Sengupta (a), V.A. Raghunathan (a) and John Katsaras (b). (a) Raman
Research Institute, Bangalore - 560 080, India. (b) National Research Council,
Steacie Institute of Molecular Sciences, Chalk River Laboratories, Chalk River,
Ontario KOJ lJO, Canada.
We have calculated the electron density maps of the ripple phase of some
phospholipids multibilayers, namely, dimyristoylphosphatidylcholine (DMPC),
palmitoyl-oleoyl hosphatidylcholine (POPC) , dihexadecyl phosphatidylcholine(DHPC) and dilauroyl phosphatidylcholine (DLPC). In all these systems except in
DLPC , the rippled bilayers have a saw-tooth shape, with one arm almost twice aslong as the other. The bilayers lack a mirror plane normal to the ripple wave
vector, thus making them asymmetric. We show that the maps of all the lipids
studied are consistent with the presence of an average tilt of the hydrocarbon
chains of the lipid molecules along the direction of the ripple wave vector. The
asymmetry of the rippled bilayers is generally assumed to arise from a saw-toothheight profile . However, we find that in the case of DLPC , the asymmetry is due
mainly to different bilayer thicknesses in the two arms and the height profile itself
is almost symmetric. Our results provide important inputs for theoretical modelsof phase transitions in lipid bilayers .
Email : varaghu@rri.res.in

- A6-110

CRYSTAL S1RUCTIJRE OF L22 RIBOSOMAL PROTEIN MUTANT RENDERINGBAC1ERIAL RIBOSOME RESISTANT TO ERYIHROMYCIN

Victor A. Streltsova, Natalia L. Davydovab and Matthew Wilcea, acrystallography
Centre/Pharmacology Department, University of Western Australia, 35 Stirling
Highway, Crawley WA 6009 , Australia, bBiophysics Section, Blackett Laboratory,
Imperial College, London, UK. ·The ribosomal protein L22 is a core protein of the large ribosomal subunit andinteracts with all domains of the 23SrRNA. L22 is involved in binding of theribosome with erythromycin, which is known as an inhibitor of protein synthesis.
It was observed that the Met82-Lys83-Arg84 triplet deletion in E .coli L22 f)hairpin produced cells resistant to erythromycin.
A mutant form of L22 from Thermus thermophilus was overexpressed in E .coli.
The crystal structure has been determined at 1.8A resolution. The f)-hairpin
conformation with three amino-acids deletion is significantly different from that in
the native L22. The f)-hairpin is bent inside of the ribosome tunnel modifying theshape of the narrowest part of this tunnel and affecting the L22 and 23SrRNAinteraction.
23SrRNA nucleotides of domains II and V participating in erythromycin binding
are located on the opposite sides of the tunnel and appear to be brought to thosepositions by the interaction of the 23SrRNA with the L22 f)-hairpin . Mutation in
the L22 f)-hairpin destabilizes the erythromycin binding "pocket" . Erythromycin,
while still be able to communica te with one of the tunnel sides , cannot reach bothits preferable sites of binding simultaneously and therefore is unable to block thepolypeptide growth.

Email: strel@crystal.uwa.edu.au

A6-111

DESIGN OF A [3 TURN-ll CONFORMATION WI1H a, [3- DEHYDRO-RESIDUES AT(i+l) POSmON: SYN'IHESES, CRYSTAL STRUCTURES AND MOLECULARCONFORMATIONS OF THREE PEPTIDES: (I) N-carbobenzoxy- ~Val-Ala-Leu-OCH3(II) N-Carbobenzoxy- Mle-Ala-Leu-OCH3 and (lll) N-Carbobenzoxy- ~u-Ala-Leu­
OCH3.

Vijay Kumar Goel, Sharmistha Dey, Jyoti Makker, Sohini Mukhe:rji, P. Kumar, R.
Vijayaraghavan ,and T .P .Singh, Department of Biophysics, All India Institute ofMedical Sciences, New Delhi 110029, India
Highly specific peptide structures can be designed by inserting dehydro-residues
into peptide sequences. The conformational preferences of branched [3-carbon
residues are known to be different than other residues. It has been shown thatthe non·- branched [3-carbon dehydro-residues induce [3-turn II conformation whenplaced at (i+2) position while branched [3-carbon dehydro-residues induce [3. -turn
III conformation. However, the effects of various dehydro-residues, whensubstituted at (i+ 1) position are not yet fully understood. In order to clearly define
the role of dehydro-residues for peptide design through their substitutions at (i+ 1)
position, three peptides: (I) Cbz-~Val-Ala-Leu-OCH 3 (II) Cbz-~Ile-Ala-Leu-OCH sand (III) Cbz-~Leu-Ala-Leu-OCH 3 were synthesized , two with branched [3-carbons
and the third with a non-bra nched - [3-carbon dehydro-residue. Because of the
branching at the [3 -carbon, the bond angles ca-c~ -cY in (I) and (II) are significantly
different [123 .3(5) 0 and 122.6(5) 0 respectively] than that observed in ~Leu[127.9(4) 0 ]. Despite this, the structures of the three peptides were found to be
identical as all the three a dopt [3-turn II conformation with torsion angles : (I) cp 1 =41.5(5) 0 , \jf 1 = - 142 .3(3) o ; cp 2 = -91.2(4) 0 ; \jfz = 8 .1(4) 0 (II) cp 1 = 37.0(6) 0 , \j/ 1 = 123.6(4) 0 ; <jl 2 = -93.4(4) 0 ; \jfz = 11.0(4) 0 and (III) cp 1 = 47.7 (5) 0 , \j/ 1 = -137.4(3) 0 ; <jl 2 =-87 .3(4) 0 , \jfz = 9 .8(4) 0 • All the peptide structures are stabilized by intramolecular
4---71 hydrogen bonds with distances of (I) N3 -----00' = 2 .69(6)A (II) N3 -----0 0' =2 .897(4)A and (III) N3 -----0 0 ' = 3.186(4)A. Though, the space groups are same,
their molecular packings are different a s in the former two, there are twointermolecular hydrogen bonds whereas, the latter has only one hydrogen bondindicating dissimilar intermolecular interactions. From these three structures , it
can be concluded that a dehydro-residue at (i+ 1) position induces a type II [3-turnconformation irrespective of the nature of branching of its side-chain.
Email : vijay2_55@r ediffmqil.com

A6-112VITAMIN E INHIBITS PHOSPHOLIPASE A2 AND INDICATES A RELIEF IN
ALZHEIMER'S AND PARKINSON DISEASES: STRUCTIJRE OF TilE COMPLEXFORMED BE1WEEN PHOSPHOLIPASE A2 AND VITAMIN E AT 1.8 A
RESOLUTION.

Vikas Chandra 1 , Jayasankar jasti 1 , Punit Kaur 1 , Christian Betzel2 & T.P.Singhl.
1Department of Biophysics, All India Institute of Medical Sciences, New Delhi110029 , India; 2 Institute of Medical Biochemistry and Molecular Biology, UKE.
C/0 DESY Notkestrasse 85, 22603, Hamburg, Germany.
Phospholipase A2 (PLA2) specifically catalyzes the hydrolysis of the acyl ester
bond at the sn-2 position of membrane phospholipids to release arachidonic acidfor the . synthesis of biologically active prostaglandins and their related
compounds, the prostacyclins, thromboxanes and leucotriens: known collectively
eicosanoids . The vitamin 'E, also known as a-tocopherol is understood to regulateeicosanoid production by inhibiting PLA2. We present here the first structuralevidence of vitamin E binding to PLA2 in the form of a detailed three-dimensional
structure of the complex formed between PLA2 a nd vitamin E a t 1.8 A resolution.
The structure reveals the details of the specific binding of vitamin E and specific· conformational changes in PLA2, upon binding to vitamin E. The PLA2 fromrussells viper (DPLA2) crystallizes as a dimer with a long interface in a back toback fashion . As a result of it the binding site of one of the moleculeS is notaccessible to non-aggregated phospholipidic inhibitors and substrates. Thus
vitamin E binds to only one molecule and inhibits its function. When activity ismeasured with aggregated phospholipids it shows 50% activity, However withmonodisperse substrates the enzyme shows no activity. It indicates that theactivity of DPLA2 against ordered membranes ca'n not be inhibited beyond 50%.
It appears to be a self-defence mechanism to keep the physiologi~al functions
going. The structure of the complex h a s been refined to an R-factor of 0.197. The
overall conformations of two molecules are essentially similar. The only difference
occurs in the binding site particularly in the orientation of Trp31. The binding ofvitamin E to one molecule of DPLA2 is strong with various hydrogen bonds andvan der Waals interactions. The binding sit~ in the other molecule is empty.
Email : vikas_chandra@hotmail.com

A6-113
ARISTOWCIUC ACID BWCKS THE ARACIDDONA1E ACID CASCADE TO
DECREASE INFLAMMATORY EFFECTS: CRYSTAL S'IRUCTIJRE OF A SPECIFICCOMPLEX FORMED BE'IWEEN PHOSPHOLIPASE A2 AND ARISTOWCIUC ACID
AT 1.7 A RESOLUTION.

Vikas Chandra 1 , Jayasankar jasti 1 , Punit Kaur 1 , A. Srinivasan 1 , Christian Betzel2& T.P.Singh I. 1Department of Biophysics, All India Institute of Medical Sciences,
New Delhi-110029, India; 2Institute of Medical Biochemistry and Molecular
Biology, UKE. C/0 DESY Notkestrasse 85 , 22603 , Hamburg, Germany.
Phospholipase A2 (PLA2) mediated hydrolysis of fatty acids, especiallyarachidonate from the sn-2 position of membrane phospholipids is importantbecause this rate limiting step liberates the requisite substrate for thebiosynthesis of eicosanoids . and it has been implicated in the pathogenesis of
inflammatory diseases. Recently, it has been found that aristolochic acid inhibits
phospholipase A2 in vitro and also decreases oedema induced by snake venom orhuman synovial fluid PLA2. Here we present the first structural evidence of theinhibition of PLA2 by aristolochic acid. The purified PLA2 from Daboia russellipulchela (DPLA2) was co-crystallized with access of aristolochic acid after
incubating the mixture for 6 hours. The crystals belong to orthorhombic spacegroup C222 1 with a=76.1, b=89 .5, c=76.9 A. The structure was refmed to an Rfactor of 0.184 (R-free=0.201) . The structure contained 1888 protein atoms fromtwo molecules in the asymmetric unit, one sulfate ion, 2 glycerols, 2 dioxanes, 1
acetate, 1 complete molecule of aristolochic acid and 312 water molecules. The
overall structure of the two molecules in the asymmetric unit is essentially similar
but the hydrophobic channels including Trp31 are considerably different. The
hydrophobic channel of one of the molecules has shrunk significantly due to theassociation of two molecules while in the second molecule, it is appropriatelyordered . As a result of this change, the aristolochic acid is able to bind only to one
molecule whereas the binding site of second molecule is empty. The enzyme assay
with micellar substrate, still shows 50% activity indicating that the aggregatedsubstrate can induce a suitable conformation in the second molecule to generate
products but isolated inhibitors or substrate molecules do not succeed in enteringto the active site of the conformationally constrained molecule.
Email : vikas_chandra@hotmail.com

A6-114PRELIMINARY CRYSTALLOGRAPHIC SnJDIES
PHOSPHATASE OF SalmoneUa typhimurium.

OF

NON-SPECIFIC

ACID

R. D. MakdeS, Vinay KumarS, V.S. YadavaS, A. S . Rao* and S. K. Mahajan*. SSolid
State Physics Division, *Molecular Biology & Agriculture Division, Bhabha Atomic
Research Centre, Mumbai 400 085, INDIA.

Non-specific acid phosphatases (NSAP) catalyze phosphomonoester hydrolysis.
NSAP-A gene (phoN) of Salmonella typhimurium was expressed in E coli using
pSK- plasmid as cloning vehicle. Protein purification was achieved by ion
exchange, hydroxy-apatite and phenyl sepharose column chromatographymatrices using Biologic LPLC system. DNA sequencing of the construct using
automated Perkin-Elmer DNA sequencer confirmed amino acid sequence of theprotein. Size of the signal peptide (20AA) was asertained using N-terminal
sequencing of the mature protein. The protein has been crystallized using
modified sparse matrix grid. The protein crystallizes in C222 1 space group withtwo molecules of 27kDa in the asymmetric unit and unit cell parameters of a=45,
b=l90, c=l06A. Crystals growing in a day were observed to be highly mosaic withmosaic spread estimated to be -1 °. The 3-dim intensity data to 3A resolution has
been acquired with R-AXIS IIC and MAR imaging plate systems using rotating
anode x-ray generator. Molecular replacement calculations using homology
derived model are in progress.
Email: vinay@magnum.barc.ernet.in

A6-115RATIONAL PROTEOMICS:
PREDICTING 1HE STRUCIDRES, FUNCTIONS,COFACTORS, SUBS'IRATES, INHIBITORS AND MULTIMERIC FORMS OF 1500
HYP01HETICAL GENE PRODUCTS IN 1HE SCOR FAMILY.

W.L. Duax 1· 2 , A. Addlagatta 1 , and V. Pletnev3. 1Hauptman-Woodward Medical
Research Inst. , Inc. , Buffalo, NY 14203, 2 SUNY, Dept. of Structural Biology,
Buffalo, NY, and 3Shemyakin-Ovchinnikov lnst. of Bioorganic Chemistry, Moscow,
Russia.
We have developed procedures for structure, sequence, and functional analysis offamilies of enzymes having 30% amino acid identity with a known crystal
structure that can reliably predict the three-dimensional structure, cofactor
preference, biological function, probable substrate, lead compound for inhibitor
design, role of surface residues in multimer formation and tissue specificity, andprobable relation of multimeric formation to function of thousands of hypotheticalgene products. Our results have the potential for successful application to
unknown gene products having as little as 20% homology with a known crystal
structure. The short chain oxidoreductase (SCOR) family of enzymes includes
over 1500 members identified in seqt:Ienced genomes. Over 200 of these enzymes
have been functionally characterized and the crystal structures of twenty havebeen reported . Sequence analysis and homology modeling have been used todefine the signatures of subgroups of the 1000 SCOR proteins of unknown
function. The signatures of subgroups of the SCOR superfamily are composed of
40-50 residues conserved at 80% homology or better distributed throughout theseven ~-strands and six a-helices of the Rossman fold. Many of the conserved
residues are in direct contact with each other and/or with the NAD or NADP
cofactor. The conservation of almost all residues in contact with the cofactor
illustrate a jigsaw lock-and-key fit that suggests strict co-evolution of fold andcofactor. Asp or Arg residues associated with NAD and NADP binding respectively
occur on the ~2a3 turn in 75% of 900 member of the SCOR family and can bereliably used to predict cofactor presence of unknown proteins . Quasi-conserved
aromatic and charged residues on the outer surface of the a5 helix stabilize
dimerization and variations in the pattern of these quasi-conserved residues
control the details of dimer association and generate subfamilies of multimericforms. Co-variance at the 30% or lower level of residues in the active site or on
the enzyme surface can be used to predict substrate preference and cell andmembrane specificity. This research is supported by NIH Grant No. DK 26546.
Email : duax@hwi.buffalo .edu

A6-116PRELIMINARY X-RAY ANALYSIS OF

1WO

DNA BINDING PROTEINS IN

ARCHAEA

Wang Ganggang*, Xue Hong#, Bartlam Mark*, Guo Rong# , Huang Li# & Rao
Zihe* 1 . Laboratory of Structural Biology, School of Life Science and Engineering,
Tsinghua University, Beijing 100084, P.R.China.#lnstitute of Microbiology.
Chinese Academic of Science , Beijing, P.R.China
A gene of a DNA binding protein in Suljolobus shibatae, sshlOb, has been
identified by bioinformatics methods , and homologous proteins to SshlOb arefound in each of all archaea species whose genomes have been completely
sequenced but not in species of either bacteria or euka:rya , which constitute
SaclOb family. This ubiquity and specificity to archaea implies an important
physiological role for these proteins. Here we report expression, purification andcrystallization of two DNA binding proteins in SaclOb family, SshlOb from
Suljolobus shibatae & MjalOb from Methanococcus Jannaschii
After heating and precipitating with 80% ammonium sulfate, followed by further
purification with three columns chromatography, homogeneous SshlOb protein
was obtained from which crystals suitable for X-ray analysis were obtained byvapour diffusion. Crystals belonging to space group P6122/P6522 with unit cella=83 .74 A, b=83.74 A, c=l64.08 A, a=P= 90°,:y=l20, and maximum resolution of
6 .5A. The crystals in monoclinic space group(C2), diffracting to 3.0 A, had unit
cell dimensions a= 177.63 A, b =60. 75 A, c= 162.32A.
At the same time, MjalOb was prepared after heat denaturation and saturation
with 80% ammonium sulfate, followed by dialysis in 0 .2M sulfuric acid and cationexchange column chromatography. Crystals obtained by vapour diffusion, diffra~t
to 2.4 A and belong to space group C2221 with cell unit parameter a=44.10 A,
b=ll8 .53 A, c=69 .09A, a=P=y= 90°.
Preparations of selenionmethionione derivative of these two DNA binding proteins
are under way in order to develop suitable crystals for structure determination bymultiple-wavelength anomalous diffraction.

A6-117

CRYSTAL STRUCTURE OF TTR COMPLEXED WITII AcCoA IN P2 1 FORM

Wang Yu, He Hongzhen, Ding Yi, Sun Fei, Le Yi, Liu Jinyuan, Rao Zihe.
Laboratory of Structural Biology & MOE Laboratory of Protein Science, School ofLife Sciences and Engineering, Tsinghua University, Beijing 100084, China
Tabtoxin Resistance protein (TIR) was found in Pseudomonas syringae pv. tabaciwith the name derived from its detoxification reaction of Tabtoxinine- ,8-lactam.
TIR, consisting of 177 amino acids residues, exhibits less than 12% sequencehomology to other proteins with known structures at the protein level. X-ray
crystallography method was used to determine the structure of TIR, which will
illustrate the molecular mechanism of its detoxification, and will show possible
significance to structural biology.
X-ray diffraction data of crystal of TIR complexed with AcCoA was collected inhouse using a Rigaku 4.8KW, 1.54 A wavelength X-ray generator and a
MarResearch 345mm image plate. The data were processed using DENZO andwas found to belong to spacegroup P2 1 with unit cell dimensions a =47 .7 A,
b=66.6 A, c=53.6 A, a = y =90°, j)=103 .7°. 2.25 A resolution crystal structure of
TTR complexed with AcCoA was solved by MR method, using the 1.55 A resolution
structure by MAD (space group is C2) as a model.
The structure is very similar to the C2 structure, with only 0.4 A RMS between
the C<X atoms of two structures. The structure shapes like a letter V, with an
AcCoA binding between the two arms, which almost has no difference to the C2
structure. However, the distance between 0 atom of carbonyl group of AcCoA and-OH group in Tyr 14l residue, which is directly related to the catalytic mechanism
of TIR, is longer than that in C2 structure. The analysis of TIR structure will
promote understanding of relationship between its structure and catalytic
mechanism.

Email; yuwang@xtal.chntu.edu.tw

A6-118
PURIFICATION AND X-RAY CRYSTALLOGRAPiflC S'IUDIES ON :MINI-INTEIN
DnaB AND DnaE

Xuehui Chen 1 , Yi Ding 1 , Rang Cao 1 , Zhicheng Wang 1 , Ming-Qun Xu2 & Zihe Raol.
Laboratory of Structural Biology, Department of Biological Science andTechnology & MOE Laboratory of Protein Science, Tsinghua University, Beijing
100084, China 1 New England Biolabs , Inc., Beverly, Massachusetts 01915, USA2·
Intein, defmed as in-framely embedded protein sequence that is removed byprotein self-splicing, contributes another layer of complexity to the central dogmaof Molecular biology. Post-translationally, the intein sequence undergoes rapid
auto-splicing and couples to ligate flanking sequences to yield a functional
external protein (extein) and an intein.
Naturally occurring inteins can be grouped into three categories: inteins that
contain a homing endonuclease between the splicing domains, inteins that lack ahoming endonuclease region (mini-inteins). and inteins in which the splicing
domain is split, and are capable of splicing in trans. Though their amino acidsequences exhibit very little similarities in their splicing domains, they seem toshare similar three-dimensional structure.
In order to gain structural insights into protein splicing, we have carried out X-ray
studies on the recombinant mini-intein DnaE and DnaB, the naturally occurring
intein from Synechocystis sp. and Porphyra purpurea with splicing activities. At
present there are no structures available on such typical mini-inteins.
The inteins were overexpressed in E.coli and purified from the crude extracts by
Impact system followed by anion-exchange and gel filtration. Crystals of both
inteins have been acquired by methods of hanging-drop vapor diffusion. A set ofdata on DnaE was also collected at 115K using a Mar345 Image Plate with an inhouse Rigaku rotating Cu anode X-ray generator at 2.9A. It belongs to spacegroup P3(1)21 with a cell parameter of a=b=58.535, c=70.197. Since no reliable
models were available for both proteins, selenomethionine derivative have been
prepared for DnaB and heavy metal derivatives for DnaE crystal are being tried
for phase determination. Further. attempts are underway to obtain better quality
crystal for high- resolution crystallographic studies.

A6-119

ALLOS1ERICREGURA'TIONAND
CARBOXYlATIONPHOSPHOENOLPYRUVA1E CARBOXYLASEMECHANISM

OF

Y. Kaia, H. Matsumuraa, T. Inouea, Y. Uenoh, T . Yoshinagac, K. Izuih, aoepartmentof Materials Chemistry, Graduate School of Engineering, Osaka University, Suita,
Osaka 565-0871, Japan, hOivision of Integrated Life Science, Graduate School of
Biostudies. Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan, coepartment of
Public Health, Graduate School of Medicine, Kyoto University, Sakyo-ku , Kyoto
606-8501, JapanThe crystal structure of active state (R-state) C 4 -form maize PEPC (ZmPEPC) has
been determined at 3.0 A resolution. The structure includes sulfate ion at theplausible binding site of an allosteric activator, glucose-6-phosphate, while it
includes no inhibitor, L-malate, at the inhibitor binding site found in Escherichia
coli PEPC (EcPEPC). The crystal structure of inactive state (T state) EcPEPC has
also been determined as the quatemary complex of Mn 2 +, PEP analogue (DCDP;
3,3-dichloro-2-dihydroxy-phost>hinoylmethyl-2-prope noate). and an allostericinhibitor, L-aspartate, at 2.35 A resolution.
From the structure comparison between R and T states PEPCs, the dynamic
movements were revealed in ZmPEPC near the catalytic site. The functionallyessential Arg64 7 (Arg587 in EcPEPC) in the unique sequence of
GRGGXXGR6 47 GG was fixed by L-aspartate in EcPEPC. The residue moves 15 A
towards the active site in the R state ZmPEPC by release from the direct
constraint of inhibitor molecule. Another essential residue, His177 (His138 in
EcPEPC) moves 10 A towards the active site in the R state ZmPEPC resulted fromthe binding of sulfate ion in the basic pocket of activator binding site.
Based on these molecular structures, the mechanisms for allosteric regulationand carboxylation reaction of PEPC will be proposed.

A6-120

S1RUCTURE-BASED ANALYSIS OF FUNCTIONAL SITE OF A TIIERMOSTABLE
ASPARTASE

Yasuo Hataa, Tomomi Fujiia, Hisanobu Sakaia and Yasushi Kawatab , alnstitutefor Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan , andboepartment of Biotechnology, Faculty of Engineering, Tottori Univer~ity, Tottori
680-0945, Japan.
Aspartase catalyzes the reversible conversion of L-aspartate to fumarate and.
ammonium ion and plays an important role in the bacterial nitrogen metabolism.
The crystal structure of the thermostable enzyme from Bacillus sp . YM55-l was
solved by the molecular replacement method using the E. coli enzyme as a searchmodel and refined for the 2.5 A low-temperature data with the R-factor of 21.9%.
The present Bacillus enzyme is a homotetramer. It exhibits no a llosteric effects,
in contrast to E. coli enzyme which is activated by L-aspartate and divalent
metal cation, but has 4-times higher activity than E. coli enzyme. The overallfolding of the enzyme subunit is similar to those of E. coli aspartase and E . coli
fumarase C which belong to the same family with the present enzyme. The
seven
revealed
enzyme
three
these
among
comparison
structuralconformationally different regions. Four of the regions were located aroundputative functional sites , suggesting the involvement of these regions intofunctions characteristic of the individual enzymes. Moreover, the increase in thenumber of intersu bunit hydrogen-bonds and salt-bridges was observed in thewhich explains theaspartase relative to the other enzymes,
Bacillus
thermostability of the present Bacillus aspartase.
Email : hata@scl.kyoto-u.ac.jp

A6-121

CRYSTAL STRUCTURE ANALYSIS OF ANTIBODY ENHANCED AFFINTIY TOWARD
A MUTATED ANTIGEN BY PHAGE DISPlAY TECHNOLOGY

Yoshiyuki Nishimiyaa, Hidemasa Kondoa, Kouhei Tsumotob and Izumi Kumagaib.aNational Institute of Advanced Industrial Science and Technology (AIST}, 2-17-21 Tsukisamu-Higashi, Toyohira, Sapporo 062-8517, Japan and bOepartment of
Biomolecular Engineering, Graduate School of Engineering, Tohoku University, 07
Aoba-yama, Aoba, Sendai 980-8579, Japan.
It is known that an antibody recognizes its target antigen with high specificity andaffinity. In some cases, however, an antibody can also recognize mutated antigens
with subtle structural changes. In order to address the molecular mechanism ofan antibody to recognize its target antigen, we have focused the interaction
between hen lysozyme (HELl and its monoclonal antibody, HyHEL-10. HyHEL-10
recognizes turkey lysozyme (TEL) with decreased affinity.
We attempted to isolate the mutant of HyHEL-10 grafting enhanced affinity
toward TEL from phage display library mutated into four residues incomplementarity-determining region 2 of heavy chain (CDR-H2) and thedetermine 3D-structures of complexes of isolated antibodies with HEL and TEL,
respectively.
The clone mutated into three residues (Tyr53 Ser, Ser54 Phe and Tyr58 Phe) ,SFSF, was crystallized by vapor diffusion method. The analysis of crystal
structures reveals that the interactions between CDR-H2 and antigen in SFSFTEL complex differ from those in SFSF-HEL complex. These led to the change inconformations of loop regions of CDR-H2 and packing of CDRs. These results
suggest that antibodies are possible to recognize different antigens in the changeof packing of CDRs.
Email : y.nishimiya@aist.go .jp.

AB-122

S1RUCnJRAL ANALYSIS OF HUMAN HEMATOPOIETIC PROSTAGLANDIN D
SYN'IHASE FOR ANTI-ALLERGIC DRUG DESIGN
Yousuke Okanoa, Tsuyoshi Inouea; Shigehiro Kinugasaa, Hiroyoshi Matsumuraa,
Yasushi Kaia, Daisuke Irikurab, Osamu Hayaishib, Masaki Yamamotoc, Takashi
Kumasakac, Masashi Miyanoc, Yoshihiro Uradeb, aGraduate School ofEngineering, Osaka University, bQsaka Bioscience Institute, cRIKEN Harima
Prostaglandin (PG) D 2 is actively formed in a variety of tissues and is responsible
for the symptoms in mastocytosis patients. PGD 2 released from mast cells is anallergic and inflammatory mediator, as demonstrated an allergic asthma modelwith the PGD receptor gene-disrupted mice. PGD 2 is formed from arachidonic acidby successive enzyme reactions: the oxygenation of arachidonic acid to PGH2 via
PGG 2 by PG endoperoxide synthase and the isomerization of PGH 2 to PGD2 by
PGD synthase (PGDS). We have determined the complex structures with PGH2
analogue and Cibacrone Blue in the presence of Mg2+ and Ca2+. The analoguebound complex structures reveal the residue's rotation of Rl4 a ctivated by Mg 2+.
The Mg2+-bound complex structure demonstrates a change of the crystal spacegroup from P2 1 to Pl and dramatic improvements of resolution from 2.0 to 1.2 A.
Cibacrone Blue shows the mixture-type inhibition against the substra t e and GSH.
The ~ value for Cibacrone Blue in the presence of Mg2+ is raised up as four times
stronger than the apo-form. The Cibacrone Blue bound complex structure shows
the B-factor of GSH is more than 70 A2 . We have to examine the presence of Mg2+
in vivo for the anti-allergic drugs.

Email : okano@chem.eng.osaka-u.ac.jp

A6-123
X-RAY CRYSTALWGRAPiflC STUDIES ON SlOO FAMILY PR01EINSZhang H. Wang Z., Wang G.#,., DingY., Wang X., Xu Y., Cheng M., Guang X.,
Bartlam M., Tang H., Barracough P.#, Rudland P.# & Rao Z. Laboratory ofStructur.a l Biology, Protein Science Laboratory of MOE, School of Life Sciences
Engineering,
Tsinghua University, Beijing l00084,China. #School of Biological
Science, Liverpool University, L69 3BX UK
The SlOO .protein family is a group of calcium-binding proteins, approximately
between 9 and 13 kDa in size, which contain two EF-hand calcium-binding
domains and share approximately 50% homology in amino acid sequence. Each·member of the family exhibits a unique pattern of expression with some cells
expressing multiple members of the family. SlOO proteins can regulate a diverse
group of cellular functions including cell-cell communication, cell growth , cellstructure, energy metabolism contraction. SlOOAl, SlOOA2, SlOOA4 and SlOOP,
four members of the SlOO protein family , play some important roles in cell
metabolism. S l 00 proteins all have a highly conserved calcium binding loop
consisting of 12 amino acids and it is flanked by two -helices (that is, the EFhand). The Ca2 +-binding site near the carboxy-terminus contains 12 amino acids
and is common to all EF-hand proteins. The low-affinity Ca2 +-binding site near
the N-terminal end is SlOO-specific, containing 14 amino acid residues. Threedimensional structures of several members of the SlOO protein family have beenreported; these studies have provided interesting data on calcium-dependent
conformation change, and the effects of mutation in the Ca2+-binding loops on
function. To obtain more detailed information about the interaction of SlOGtarget, and the significance of the 14 residue amino-terminal calcium-binding
loop, we have crystallized all four human SlOO proteins (SlOOAl, SlOOA2,SlOOA4 and SlOOP and their 3D structural analysis are in progress. After
recombination, expression, and purification, we have obtained crystals of thesefour proteins from different crystal conditions, and some pre-liminary
crystallography datas[Figl).

BufferpH
Precipitant
Additives
MethodSpace group
Cell

NaAcetate
4.6
PEG4k. (NH4)zS04
Ca 2 +
Vapor Diffusion

/ 1• =i...:.....,..' ~-· ~ ~ ~ <!!.•-

Crystal of S lOOAlCrystal of SlOOA2Cystal of Se-SlOOA4~.~7""-·

v.

:~

·. !

-.
.

..

Crystal of SlOOP

BufferPH
Precipita nt
Additives
MethodSpace group
Cell

TrisHCl
8 .5
PEG4k
Ca2+

BufferPH
Precipita nt
Additives
MethodSpace group
Cell

TrisHCl
6.0
PEG4k
Ca2+

BufferPH
Precipitant
Additives
MethodSpace group
Cell

TrisHCl
7.5
PEG4k
Ca2+

Vapor Diffusion
P6
A=b=57 .3A c=l04.7A

Vapor Diffusion
P6 or P3
a=b=47.1A, c=l75.6A

Vapor Diffusion
P2 1
a=b=77 .7 4A,c=78.42A

A6-124

CRYSTAL STRUCTIJRE OF A GCN5-RELA1ED N-ACE1YLTRANSFERASE,TAB TOXIN RESISTANCE PRO'IEIN, BOUND TO ACE1YL COENZY'ME A- A MODE
FOR TIIE SELF PRO'IECTION OF Pseudomonas syringae pv. Tabaci FROM ITS
TOXIN

Zihe Rao . Laboratory of Structural Biology, Tsinghua University, Beijing 100084,
China
Tabtoxin resistance protein (TIR) is an enzyme that renders Tabtoxin-producing
pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. We
have determined the crystal structure of TIR complexed with its substrate, acetyl
Coenzyme A (AcCoA). to 1.55 A resolution using MAD phasing methods . The
single domain protein includes the four conserved motifs of the GCN5-related Nacetyltransferase (GNAT) family, as well as a characteristic 'V' motif in which
AcCoA is inserted between the two anns of the 'V'. Our high-resolution structure
reveals a simple single-step catalytic mechanism whereby the pathogens canprotect themselves via the transfer of an acetyl group to the toxin . We also reportthat our structure provides new understanding of the role of a critical tyrosine(Tyrl41) residue that is found in the catalytic pocket of many GNAT superfamily
members , including the h~stone acetyltransferases .
Email : raozh@xtal.tsinghua.edu.cn

A6-125

CRYSTALWGRAPifiC

STIJDYOFA

CHIMERICXYLANASE

BE1WEEN

Streptomyces olivaceoviridis E-86 FXYN AND CeUulomonasjimi Cex.

2
Zui Fujimotoa. Satoshi Kanekob, Atsushi Kunoc. Hideyuki Kobayashi , !sao
Kusakabed and Hiroshi Mizunoa,d. aNational Institute of Agrobiological Sciences,
Tsukuba, 305-8602, Japan, bNational Food Research Institute, Tsukuba, 3058642, Japan, <yamagata University, Yamagata 990-8560, Japan, and dUniversityofTsukuba, Tsukuba, 305-8572,Japan
Xylanase hydrolyzes ~-1 ,4-glycosidic bonds within the xylan backbone. Two family
10 xylanases from Streptomyces olivaceoviridis E-86 and CeUulomonas fimi havehigh sequence homology in the catalytic domain (38%) but slightly different
substrate specificity against the xylan and xylooligosaccharides. A chimeric
enzyme (OC1415) between the two enzymes showed the moderate catalytic activity
between the two parent enzymes , but showed some different substrate specificity:
OC1415 did not produce xylose. To investigate the structure-function relationshipoffamily 10 xylanase, we conducted the X-ray structure analysis ofOC1415.
Crystals were obtaiped by the hanging drop vapor diffusion method at room
temperature using a 20 mg/ml protein solution and a reservoir solution composedof 28 % ammonium sulfate and 2% Mcilvaine buffer. Mter two weeks, thin needle
crystal cluster appeared. Diffraction experiment was conducted at Photon Factory.
The data sets were processed and scaled using the programs DENZO andSCALEPACK. The crystals belong orthorhombic space group ?2 12 12 1 , with celldimensions of a=48 .48, b=57.19, and c=l06.67A. Collected native intensity data
included 13,853 unique reflections with 88.3% completeness and an R-factor of
0.065 from 100 to 2.2 A resolution. Structural analysis is undergoing by themolecular replacement method .
Email : zui@affrc.go.jp

A7 : Powder 111ethods

A7-lX-RAY POWDER DIFFRACTION S1UDIES ON CdxSn 1 _xSe SOLID SOLUTION

D.Pathinettam Padiyana and A.Marikanib, aDepartment of Physics, Manonmaniam
Sundaranar University, Tirunelveli- 627 012, India and bDepartment of Physics,
Mepco Schlenk Engineering College, Virudhunagar- 626 005, India.
CdxSn 1_xSe compound with x= 0,0.25,0.3 ,0.75 and 1.0 are synthesized in aquartz ampoule by mixing tin, cadmium and selenium powders in theirstoichiometric ratio by melt technique .
The synthesized compounds are
confirmed by X-ray diffraction powder pattern as homogeneous andpolycrystalline in nature. The composition analysis of these materials are carriedout by atomic absorption spectrometer. It is well known that CdSe exists inhexagonal and cubic system whereas SnSe crystallizes in orthorhombic structure.
These two materials do not form continuous solid solution.
The powder
diffraction pattern for all the five samples are recorded in JOEL JDX 8030 powder
X-ray diffractometer. The XRD data of CdSe and SnSe· samples are indexed withthe help of JCPDS files and the unit cell parameters are refined by least squares
procedure. In the case of mixeq compounds the XRD peaks are indexed with thehelp of a graphical method and using the software DICVOL9l. The lattice
parameters are refined using software UNITCELL and listed in the following Table.
Table : Refined unit cell parameters for CdxSn 1 _xSe compoundXabc
Crystal system
0.00
11.37(5)
4 .44(2)4.02(2)
Orthorhombic
0.25
12.21(1)4.34(1)
3.94(4)
Orthorhombic
0.30
12.11(2)
4 .751(7)4 . 19(1)Orthorhombic
0.75
12.57(5)4.19(3)
3 .91(1)Orthorhombic
1.00
4.307(3)7.03(1)
Hexagonal
Email: bio@md3.vsnl.net.in

A7-2

AB INITIO X-RAY POWDER DIFFRACTION STIJDIES OF POLYMORPlllSM IN
Na20-Bi20 2-V20s 1ERNARY SYS1EM

Digamber G Porob and T N Guru Row, Solid State and Structural Chemistry Unit,
Indian Institute of Science, Bangalore-5600 12, India
A new class of oxide ion conductors in solid solution of Na2 0-Bi2 0 3-V2 0 5 ternary
system has been synthesized by solid state reaction. Two polymorphic
modifications , a.- NaBi3V2 0 10 and y- NaBi3V2 0 10 which form at 600°C and 450°C
respectively, have been subjected to ab initio structure determination via powder
X-ray diffraction. a.- NaBi3V2 0 10 is triclinic, space group P l , a= 7 . 1964(4) A, b =7 .0367(3) A, c = 5.5139(2) A, a.= 84.440(3) 0 , ~ = 113.461(2) 0 , y =112.319(2) 0 and
V =236.46(2) A3. Upon Reitveld refinement the structure refmes to Rp = 9 .94%,
Rwp = 13.11% , R (I.hkll = 8. 73% for 30 parameters and 4871 data points. The
structure is built from (Bi 2 0 2 )2+ single chains that extend along the c axis with
V0 4 units joining the chains along both a and b directions . y- NaBi3V2 0 10 is also
triclinic, space group P l, a =14 .7132(3) A, b =9.3429(2) A, c = 10.3896(2)A, a.
V = 937.37(2)A3. The final=69 .855(1) 0 , ~ =128.030(1) 0 , y =123.566(1) 0 andrefinements gave Rp =3 .84%, Rwp = 4.90%, R U.hkll = 2.44% for 107 paramet ers
and 4850 data points . The structure depicts an entirely new motif, unlike theearlier polymorph, hitherto unknown in doped Bi2 0 3-V2 0 5 system. The structureis built of (Bi 2 0 2 ) 2 + double chains extending along the [0 l 1) direction with V04
units joining these chains. Both structures depict, for the first time features
which are not common to the Aurivillius family of compounds and are likely todisplay isotropic conductivity.
Email: digamber@sscu.iisc.emet.in

A7-3

ESTIMATION OF ERRORS IN 1HE MEASUREMENTS OF UNIT-CEIL
PARAMETERS: STATISTICAL UNCERTAINTIES OF PEAK POSmONS OFPOWDER DIFFRACTION LINES DETERMINED BY INDIVIDUAL PROFILE FITTING

H. TORAYA, Ceramics Research Laboratory, Nagoya Institute of Technology,
Asahigaoka, Tajirni 507-0071 , JapanA formula for estimating a statistical uncertainty of peak position, determined byindividual profile fitting, has been derived. A magnitude of the statisticaluncertainty is given by (sum of peak profile intensitiesr 1 / 2 x full-width at halfmaximum x form factor x correlation factor x quality factor x the goodness-of-fit
index. The form factor depends on a shape of diffraction profile, and it becomes
smaller by 40% when the profile shape changes from Lorentzian to Gaussian. The
correlation factor represents the parameter correlation between the peak position
and the parameter for profile asymmetry, and it becomes unity when the profile
shape is symmetric or the parameter for profile asymmetry is fixed during theleast-squares fitting. The quality factor depends on a peak-to-background ratio.
The formula was experimentally verified by using diffraction data sets of Oi0 2 andSi powders . The statist ical uncertainty is essentially based on the counting
statistics and profile width. Therefore, the peak position of a strong and sharp
peak in the low angle region can be determined more precisely than that of a weak
and broadened peak in the high angle region. Precision of unit-cell parameters
will be discussed in connection with the optimization of experimental conditions.
Email : toraya@crl.nitech.ac.jp

A7-4

RECENT ADVANCES IN STRUCTIJRE SOLUTION FROM POWDER DIFFRACTION
DATA

M. Neumann, F. Leusen, G. Engel, S. Wilke, C. Conesa-Moratilla, Accelrys, 230/250
The Quorum, Cambridge CBS 8RE, UK
Crystal structure determination frequently is a prerequisite for the rational
understanding of the solid state properties of new materials. Even though single
crystal diffractometry is the method of choice when it comes to crystal structure
determination, this approach is often impractical because of the difficulties involved in
growing single crystals of appropriate size. High quality powder samples, on the other
hand, are much easier to obtain. Using direct-space structure solution techniques.
increasingly complex crystal structures can nowadays be solved directly from powder
diffraction data. Combined with easy-to-use tools for model building and visualisation
as well as molecular mechanics and first principles Density Functional Theory (DFT)
calculations, crystal structure solution from powder diffraction data is becoming aroutine task. To illustrate the applicability of direct-space Monte Carlo techniques tothe crystal structure solution of organic and inorganic compounds, a variety ofstructure solutions ~th the program Powder Solve will be presented.
Recent advances include the determination of a preferred orientation correction during
the structure solution search and the use of parallel tempering, a newly implemented
global search algorithm. As a complementary technique, first principles DFT
calculations have been used successfully to validate structure solutions and to aid the·subsequent Rietveld refinement.
Email: mneumann@accelrys .com

A7-5

S'IRUCIDRAL SIDDIES OF CRYSTALLINE, MICROPOROUS ALP0 4 -18 AND
METAL SUBSTITU'IED ALP0 4 -18

Mahesh Bhagwat and Veda Ramaswamy. Catalysis Division. National Chemical
Laboratory. Pune 411 008. India
Zeolites and related materials show exciting applications in the field of catalysis inwhich their highly ordered framework structures containing pores play a major
role. The chemistry of zeolites and other molecular sieves cannot be understoodfully without the structural information since both are intimately related. AlP0 4 18 (AEI) is a crystalline, microporous aluminophosphate molecular sieve having aneutral framework charge. Incorporation of divalent metals like Mg. Zn, Mn, Ni
etc. in the framework imparts acidic character to the framework. These metal
substituted molecular sieves find exciting catalytic activity for conversion of
methanol to light olefms. The structure of the neat AlP0 4 -18 synthesized using
tetraethylammonium hydroxide as the structure-directing agent is monoclinic.
There are no structural characterization reports on the metal substituted AlP0 4 18 using powder X-ray diffraction technique. We report the structuralcharacterization of metal (Mg and Zn) substituted AlP0 4 -18 using powder X-ray
diffraction and NMR techniques. The powder x-ray diffraction patterns of themetal substituted samples show remarkable decrease in crystallinity as comparedto the neat AlPO. which decreases with the increasing concentration of metal
atoms. Incorporation of the metal in the framework results in decrease in thesymmetry of the sample as the space group changes from C2/c for the neat
AlP0 4 _18 in the monoclinic system to P2 1 for the metal substituted samples.
Variation in the lattice parameters of the samples observed with the increasing
metal concentration indicates metal incorporation in the framework.
Email : mahesh@cata.ncl.res.in/veda@cata.ncl.res.in

A7-6

DIFFRACTION
POWDER
1RANSffiON OF CEAL03

STIJDIES

OF

lfiGH-TEMPERATIJRE

PHASE

M. Tanakaa, T . Shishidob T. Moria and H. Horiuchic, aphoton Factory, High Energy
Accelerator Research Organization, Oho Tsukuba 305-0801 Japan, bJnstitute forMaterials Research, Tohoku University, Katahira Sendai 980-8577, Japan andcnepartrnent of Natural Science, Faculty of Education, Hirosaki University,
Bunkyocho Hirosaki 036-8560, Japan.
I

CeA10 3 is one of the compounds of a series of perovskite-type rare-earth alminium
oxide (REA10 3 ) . In these compounds the crystal symmetry and phase transition
temperature systematically change according to the ionic radius of the rare-earth,
but CeA10 3 is an exception to this tendency [1,2] . We have been investigating thedetailed structure and tried high-temperature synchrotron X-ray powder
diffraction experiments . Experiments were carried out at the beam line 3A of
Photon Factory. The synchrotron radiation from a bending magnet ismonochromatized and horizontally focused by a Si( 111) double-crystal
monochromator. The wavelength is 1.38(A) . The 3-circle-4-axis diffractometer witha Si( 111) analyzer monochromator was used as a powder diffractometer. A hightemperature fumace with sample rotation system was used for sample heating.
Powder diffraction profiles of selected peaks were observed changing sample
temperature from 300K to 550K by theta-fix 2theta-scanning method. Analysis of
obtained profiles by a profile-fitting program, 'PROFIT[3]' revealed existence ofphase transition at about 546(K). The transition from orthorhombic torhombohedral is consistent with other REA10 3 but the temperature is muchdifferent from others.
[1] A. Saitow, et al., J . Appl. Cryst. ,31 ,663-671(1998) .
[2] M.Tanaka, et al., J. Alloy Compd. 192,87-89(1993).
[3] H. Toraya, J. Appl. Cryst., 19,440-447(1986) .

Email : masahiko.tanaka. pf@kek.jp

A7-7
INVESTIGATIONS ON THE SYNTHESIS, S1RUCTURAL AND MICROS1RUCTURAL
CHARAC1ERIZATIONS OF MG BASED ~PtCJ.s 'IYPE ~Fells) HYDROGEN
STORAGE MA1ERIAL PREPARED THROUGH MECHANICAL ALWYING

S.S. Sai Ramana, D.J. Davidsona, J.-L. Bobetb and O.N. Srivastavaa, aoepartmentof Physics, Banaras Hindu University, Varanasi - 221 005, India, bJnstitut deChimie de la Matiere Condensee de Bordeaux, Universite Bordeaux I, Avenue du
Dr A Schweitzer, 33608, Pessac, Cedex, FranceThis paper deals with the formation of a new ternary hydride Mg2FeH 6 (K2PtC16type) in a single step procedure following the process of mechanical alloying of
initial stoichiometric ingredients Mg and Fe under hydrogen ambient. The
optimum yield of formation of single phase Mg2FeH 6 was achieved by hydrogen(-10 atm.) milling of constituent elements at a speed of 400 rev. min- 1 for various
milling duration. The structural characterization of the ball milled (2Mg+Fe)
powder was carried out using Philips X-ray diffractometer by taking out the
sample intermittently from the attritor mill in regular intervals of time. It was
found that the Mg2FeH 6 phase starts forming at a milling duration corresponding
to 14 hrs. and the optimum Mg2FeH 6 phase formation was obtained at 20 hrs.
The propbrtion of this phase was estimated by employing Rietveld refinement
analysis of the x-ray powder diffraction data and it was found to be 63%. This is
the highest phase proportion reported so far for the Mg2FeH 6 phase when formed
from elemental Mg and Fe following the route of mechanical alloying. Together
with Mg2FeH 6 phase, some quantity of Fe (about 37%) is also present. It may bepointed out that Fe being a magnetic impurity can be removed leaving the
Mg2FeH 6 content to be nearly 90-100%. However, such purification was not donein the present investigation. In order to see further changes. we have also
investigated synthesis of the material obtained by longer milling duration of 25,
28 and 30 hrs. The XRD patterns for the 25, 28 and 30 hrs. ball milled materials
revealed that the intensity of Mg2FeH 6 peaks get reduced in comparison to Fe
peaks. This implies that beyond 20 hrs, there is no further increase in the phase
proportion and the amorphization starts taking place. The post-sintering processof these mechanically alloyed samples did not improve the Mg2FeH 6 phase
proportion and yield as evidenced through XRD. The x-ray structuralcharacterizations revealed that the as-milled Mg 2FeH 6 material (milling durationof 20hrs; under H 2 pressure -10 atm., speed -400 rev. min- 1) corresponds to the
known face centered cubic structure with lattice parameter a = 0.6446(2) nm.
The elemental (chemical) compositional analysis has been carried out for themechanically alloyed Mg2FeH 6 materials using EDAX technique. The results
confirm the correct stoichiometric ratio of the initial mixture (2Mg+Fe). The
surface morphologies of the (2Mg+Fe) mixture before and after mechanicalalloying have been performed using scanning electron microscopic technique. The
SEM explorations reveal the spongy like feature of Mg2FeH 6 agglomerates.
Email: ons@banaras.ernet.in or hepons@yahoo.com

A7-8
STIJDY OF CRYSTAL STRUCTIJRE OF DOUBLE
Sr2 (FeMo)Oa

PEROVSKITE MATERIAL

Le Thi Cat Tuong, Phan Vinh Phuc and Le Hoang Son, Institute of Materials
Science, Hoang Quoc Viet Street, Cau Giay, Hanoi,Vietnam

In this paper we report our recent results of crystal structure investigation by Xray powder diffraction method for Sr2 (FeMo)0 6 . The samples were prepared byconventional solid state reaction. The lattice constants were determined by WINMETRIC programme on the basis of face centered cubic Bravais lattice's unit-cell.
The simulated X-ray diffraction spectrum of this material was calculated. The
obtained results show that the material has space group symmetry of Fm3m
(225). with the lattice constant a = 7.8930 A and chemical composition ofSrz(FeMo)0 6 . The crystal structure of this material has ordered structure of NaCl
type with Fe and Mo being alternatively located in sites 4a (4b); strontium atoms
are in sites Be and oxygen atoms are in sites 24e. The distances of the atoms inunit cell were calculated. Magnetic properties and Raman spectrum ofSrz(FeMo)0 6 were also studied.
Email : pvphuc@ims.ncst.ac.vn

A7-9

COMPUTATION OF S'IRAIN 1ENSOR AND SHAPE OF CRYSTALLI'IES IN SILKI MODIFICATION OF BOMBYX MORI

Sangappaa, Kenji Okuyqrnab and R. SomashekarC, aoepartment of Physics,
Yuvaraja's College J\1ysore-570 005 , lYfokyo University of Agriculture andTechnology, Koganei, Tokyo 184-8588, Japan, coepartment of studies in Physics,
University of Mysore. Manasagangotri, Mysore -570 006, In.dia
Using the X-ray powder data obtained from Bombyx mori Silk fibroin in Silk I
modification, we have estimated the strains using profiles of several (hkl)reflections observed in the fibroin. For this purpose, we have used line profile
simulation and matching with the experimental, on the basis of a paracrystalline
one-dimensional Hosemann's model proposed by us[1]. The shape of thecrystallite and size along different directions in the fibroin have also been
estimated and presented here. From these results the strain tensor has been
computed using the approach given by Wilke and Martis[2,3]. The effect of thesestrains on the molecular arrangement within the crystal structure and hence toidentify the portion of the chain within the unit cell which participates in inducing
the intrinsic strain during the formation of the fiber are being investigated.
[1] R. Somashekar and H. Somashekarappa, J. Appl. Cryst., 30, 147 (1997).
[2] W. Wilke and K.W. Martis, Colloid and Poly. Sci., 252, 718 (1974).
[3] K.W. Martis and W. Wilke, Progr. Colloid and Poly. Sci. , 62, 44 (1977).
Email : rs@uomphysics.net; rsshekar@sancharnet.in

A7-10SYN'IHESIS AND X-RAY POWDER DIFFRACTION STUDY
1ETRAHEDRAL STRUCTURE COMPOUND CUZNG.Aa1E6

OF

DEFECT

Rashmia and U.Dhawanb , ax-ray Analysis, National Physical Laboratory,
Dr.K.S.Krishnan J\:1arg, New Delhi 110 012 , India and bretired scientist, National
Physical Laboratory.
Normal tetrahedral structure quaternary compounds crystallize either in stannitetype structure or wurtzite stannite-type structure where cations have orderedarrangement. Simple zincblende or wurtzite-type structures are observed for thecompounds with no ordered cation arrangement. Not many 'defect-tetrahedral
structure' quaternary compounds have been investigated so far. CuZaGa3Te 6 wassynthesized by the melt and anneal technique. X-ray powder diffraction data werecollected in the 28 range from 20° to 158° on a Siemens 0500 X-ray diffractometerwith a Cu-target source in conjunction with a scintillation detector and a graphite
monochromator in the diffracted beam. The diffraction pattern was indexible on abody-centered tetragonal cell with a=0 .5946(2)nm and c=l.l891(5)nm. The X-ray
density, Dx was calculated as 5.8l x l03kgjm3. The compound Omay be
crystallizing in a defect chalcopyrite-type structure, space group I 4 with Z=4/3.
Email : rashmi@csnpl.ren.nic.in

A7-11RIE'IVELD REFINEMENT OF COPPER DOPED IACUxC01-x 03

Veda Ramaswamy, Catalysis Division, National Chemical Laboratory, Pune 411
008, India
Perovskite type of oxides such as La 1 _xAxB0 3 with A=Ca, Sr. Ba and Ce and B=Co,
Mn, Ni and Fe have been used as catalysts for the methane combustion and theactivity increase is seen with increase in ionic conductivity with the introductionof oxygen and due to cem;ceiV redox couple. LaCoLxCux03 samples with copper
content varying from 1-20 mol% were prepared using citrate complexation method
and the Rietveld refinement of their powder XRD profiles was carried out using
the program FULLPROF. The samples were scanned on STOE/STADI-P withtransmission geometry. The program TREOR was used to index the powder
pattern, which gave a hexagonal cell, and the refinement was started with themodel having space group R3_c with constraints on the occupancy of copper andcobalt to be equal to one. The Rietveld refinement gave precise fitting for eachsample with a reliability factor (Rwp) less than 4 .8 - 6. 7% and the goodness of fit
varies from 1.18-1.22 for all the four samples. The substitution of cobalt by Cu 2 +tends to increase the cation-oxygen-cation interactions. This substitution leads toa postive defectivity, which in tum should be compensated by oxygen vacancies in
the absence of Co 4 + species. The values of the Co-O bond distance for all samples
varied in the range 1.931-1.932 A which is lower than the expected on the basisof ionic radii which could be due to covalent contribution to the bond. The
cooperative breathing modes of M-0 bonds and the labile oxidation states areprobably responsible for the catalytic activity, electrical conductivity and oxygen
transport property of transition metal perovskite structures.
Email : veda@cata.ncl.res.in

A7-12

A CLEVER METIIOD OF QUANTITATIVE ANALYSIS OF ALUMINUM-RICH
MULLITE

Xinkan Yaoa, and Jianmin Haob, acentral Laboratory, Nankai University, Tianjin
300071, China, and hTianjin Electronic Materials Research Institute, Tianjin
300192, China.
Mullite is an important ceramic material. Its typical chemical composition is
3A12 0 3 ·2Si0 2 . In fact, frequently the actual chemical composition of mullite
samples deviates from this ideal value owing to the different preparation
technology, but its structure framework is still invariable. The quantitative
analysis of mullite means to determine the content of mullite in a mixture system,
which is composed of polycrystalline mullite and some amorphous products in
preparation. The difficulty lies in that the intensities of diffraction peaks of themullite phase are variable along with the different ratio of Al and Si atoms of themullite phase.
Using structure parameters of different aluminum-rich mullites, we caculated
their K(hkl) values. K(hkl) = M(hkl) I F(hkl) 1 2 Lp(hkl). Here F(hkl) is the structure
factor of (hkl) reflection, M(hkl) is the multiplicity factor and Lp(hkl) is the Lp
factor. The K(hkl) value of every hkl reflection is variable along with the different
ratio of Al/Si. We selected and analyzed those reflections, the K(hkl) value of
which changes linearly along with the ratio of Al/Si. We found that the
combination of the integrate intensity of three reflections I(lOO) + 0.56[1(120) +1(210)] is not variable. Provided the integrate intensity of these three reflections ofsamples is determined, the quantitative analysis of mullite can be completed
rapidly and accurately.
Email : yaoxk:@centlab.nankai.edu.cn, yaoxk:@public. tpt. tj .en

AB:Aperioficsttucrur~AB-1A DISSECTION OF 11IE GUMMELT DECAGON LEADING TO A CLASSIFICATIONOF GUMMELT-TYPE PATIERNSE A LORD. Department of Metallurgy, Indian Institute of Science, Bangalore
560012, India
Steinhardt et al. have proposed a model for the structure of decagonal Al-Ni-Co,
built from overlapping clusters of a single type . The structure arises from adecoration of the decagons of a Gummelt covering. The unit (essentially adecagonal prism) was called by Steinhardt et al., a "quasi unit cell" . We propose aclassification scheme for patterns derivable by decorating the Gummelt decagon.
The classification makes use of the fact that G-patterns can also be derived fromdecoration of a tiling of the decagon. The corresponding tiling patterns employ
three kinds of tile, and are a modification of the Penrose 'kite and dart pattern'
The tiles are analogues, for decagonal quasiperiodic patterns, of the "asymmetricunits" of a periodic pattern; and special points on the tiles are analogues of
Wyckoff positions. This provides a simple mode of description and classification of
all "Gummelt-type structures".
Email : lord@metalrg.iisc.ernet.in

AB-2
1HE MODUI.A1ED STRUCTIJRE OF COPPER-(4,4'-BIPYRIDYL SULFA1E
COORDINATION POLYMER COCRYSTALLISED WITii 1ERAPHTIIALIC ACID

Kenneth J. Hallera, Weenawan Somphona, A. David Raeb and Ian D. Williamsc,
aschool of Chemistry, Institute of Science, Suranaree University of Technology,
Nakhon Ratchasima 30000, Thailand, bResearch School of Chemistry. Australian
National University. Canberra. ACT 0200 , Australia, cDepartment of Chemistry.
Hong Kong University of Science and Technology. Clear Water Bay, Kowloon,
Hong Kong.
Solvothermal reaction of copper sulphate, teraphthalic acid and 4,4'-bipyridine
gave yellow crystals [Cu(ClOH8N2))4(S04)2.2(C8H604). a 19.597(4). b 34.771(3).
c 34.771(3). 13 107.52(3), C21c. Z = 8) describable as a commensurate modulationof an idealised Z = 2 parent structure with aP = al2. bP = bl2. cP = c. In theparent, polymeric chains of [-Cui-bipy-Cui-bipy-1 are propagated by an n glide,
1l2+x,l/2-y.-ll2-z, and are cross linked (Cu-0-S-0-Cu) by the sulfate groups
which lie on 2 fold axes. The teraphthalic acids lie on centres of inversion andhydrogen bond to the sulfates . The parent n glide cannot remain a symmetry
element of the modulated structui·e. A (3+ 1) dimensional approach , modulation
vector (ap*+bp*)l2. suggests the possibilty of a twinned triclinic crystal but
observations of weak reflections with h even. k even. h+k=4n+2 . preclude thisoption. A (3+2) dimensional approach with modulation vectors q.p* 12. bp* 12
allows for space group C21c with four options for the selection of the quarter ofthe parent structure symmetry elements to be retained. Reverting to the standard
setting this allows four origin options for the asymmetric unit but originsl I 4 , 1 I 4,0 apart do not correspond to alternative origins for the asymmetric unitof the parent structure . In the correct model, the teraphthalic acids no longer sit
on inversion centres. Some residual disorder about a 2-fold axis remains but anordered structure in a lower symmetry space group was shown to beinappropriate.
Email : haller@ccs.sut.ac. th

AB-3
S1RUCTURE OF 3-MERC.APTO 4-N(4'-CHLOROBENZYLIDENE)-5-PHENYL, 1,2,4TRIAZOLE

Narasimha Murthy VN, Kokila MK. Puttaraja, Kulkarni MVa and Shivaprakash
NCh.Department of Physics , Bangalore University, Bangalore 560 056 ,aoepartment of Chemistry, Kamataka University, Dhat-wad 580 003,
bJnstrumentation and Service Unit, Indian Institute of Science, Bangalore 560 012
Derivatives of 3-mercapto-5-phenyl 1, 2, 4-triazole have shown promise as
antibacterial, antifungal and anti-inflammatory agents while they show very goodtherapeutic activity, they are a lso known to present a certain degree of mutagenic
and carcinogenic properties . This may be due to the byproducts formed during
their metabolism. The triazole derivatives are synthesized by the reaction of
simple condensation of an amine and an a ldehyde in a lcoholic medium to form
azomethine linkage(-N=CH-). The titJ.e compound, C 15 H 11 N4 S Cl synthesized bythereaction
4-amino-3-mercapto-5-phenyl
1,2,4-triazole
with
4cholorobenzaldehyde in absolute alcohol has been screened for its antimicrobialactivity.
The colorless platy crystals of the title compound were obtained using ethanol a s
the solvent. It crystallizes in monoclinic system, space group P2 1 /c with
a=18 .6686A. b=4.0824A, c=19.5796A. ~=102.3548°, V= 1457.65A3 and Z=4 . The
intensity data were collected on an Enraf Nonius CAD4 diffractometer. The
structure was solved using direct methods and refinement by full matrix method
using SHELX97. The final R value converged to 5.56% . The conformational
analysis will be discussed in detail.
Email : vnnmurthy@rediffmail.com

AB-4

MODUIA1ED APERIODIC CRYSTAL S1RUCTIJRE AND SUPERCONDUCTING
MICROMECHANISM IN YBa2Cu 3 0x COMPOUNDS

Nguyen Van Tri, Institute of Engineering Physics, Hanoi University of Technology.
P.CHT, C2-l0l, Dai hoc Bach khoa, l Dai Co Viet Road, Hanoi, Vietnam.
From the ESR experimental results, two different types of the Electron Spin
Superexchange Couple Pairs [Cu-Y-Cu] in YBa2 Cu 3 0x (YBCO) ceramics have been
revealed: A singlet pair (i J,) on the long diagonal of the twined Y-unit-cell by adistorted (a,b) angle e "' 72° corresponds to the superconducting phase and a
triplet pair (ii) on the short diagonal of the twined Y-unit-cell by 0 "' 78°
corresponds to the semiconducting phase. The persistence of the spin couple
pairs as well as the superconducting micromechanism in YBCO correlates wellwith the modulated substructure . system in the material. On the basis of the
behaviour of the quasi-free electrons in theY-unit-cell as a Nano Resonant Cavityof the short-range order structure of the material some important issues can betheaddressed. Some examples are the existence of the energy gaps,
-l-)
(i
pair
singletthewherefundamentals of the superconductivity in YBCO
revealed plays the role of the "Cooper Pair", an equation determining thesuperconducting transition temperature Tc, and an equation determining thetemperature Tx of the conductivity maximum point in the semiconducting phase.
The calculated results are in a very good agreement with the respective measured
data.
Email : nvtri@mail.hut.edu.vn

AB-5
A DETAILED ELECTRON DIFFRACTION STIJDY OF 1HE FERROELECTRIC ANDFERROELASTIC a POLYMORPH OF ~o0 3F3 .

F.Brinka, R.L.Withersa, L.Norena, K.Frieseb and G.Madariagab, aResearch Schoolof Chemistry, Australian National University, Canberra, A.C.T, 0200, Australia,
and hOepartamento de Fisica de la Materia Condensada, Universidad del Pais
Vasco, Bilbao, Spain.
1
K3M003F3 is a representative member of the A l+ 2B +MVI03F3 {A, B = K, Rb,
Cs; MVI = Mo, W) family of elpasolite related oxyfluoride phases and undergoes
two reversible structural phase transitions on cooling from the highest-

temperature, ideal cubic (Fm3m) y polymorph. The room temperature a polymorph of these phases is ferroelectric and ferroelastic. Problems associated with pseudosymmetry and twinning have led to much confusion in the literature as regards
the unit cell and space group symmetry of this polymorph. A detailed electron
diffraction and XRPD study has been made of the ferroelectric room temperaturea polymorph of K3M003F3. It is shown that the true symmetry of this polymorph
is neither tetragonal, trigonal or triclinic as previously reported but rather
monoclinic Ilal, a = 2ap-c , b = 4bp, c = ap+2cp when expressed in terms of theunderlying elpasolite (ordered perovskite) parent structure type. The sharp
satellite reflections characteristic of the monoclinic supercell are shown to fall on
and to co-exist with a highly structured, continuous, three-dimensional diffuse
intensity distribution (presumably arising from local 0 /F ordering and associatedstructural relaxation).
Email : withers@rsc.anu.edu.au

AB-6

PURIFICATION AND STUDY OF ITS EFFECT OF POLY'IYPISM IN SOLUTIONGROWN CADMIUM IODIDE CRYSTALS USING X-RAY DIFFRACTION.

S.K. Chaudhary, Harjeet Kaur, University College, M.D .University, Rohtak12400 l (India)
The Cadmium iodide has been purified using a zone-refining method fabricated byus. The crystals have been grown in two batches using unpurified and purified
material. A comparative study has been made on these batches for polytypism
using x-ray diffraction technique . Total number of polytypes involved are 360.
Formation of small period polytype 2H is governed by both temperature andimpurities contained in the starting material. 4H is the most stable polytype.
Higher occurrence of unidentified polytype in crystals of purified material has
been attributed to free movement of edge dislocations during growth. The results
have been examined against empirical considerations of earlier investigations .

AB-7

TilE QUASICRYSTAL-TO-CRYSTALAPPROACH FOR d-Al-Co-Ni.

TRANSFORMATION

UNIT

CLUS'IER

M. Honal and T.R.Welberry. Research School of Chemistry, Australian National
University, Canberra ACT 0200, Australia.
Experimental studies provided evidence for a transformation between decagonalquasicrystal phases and periodic approximants. leading to orientationally ordered
crystalline nanodomain structures.
Theoretical work on the quasicrystal-to-crystal transformation is mostly
concentrating on higher-dimensional models. Authors use the phason-strain
formalism or general shears and rotations of the hyperlattice. These approaches,
however, say little about real atomic-scale processes.
A geometrical model for the quasicrystal-to-crystal transformation of d-Al-Co-Ni
was developed previously, based on computer simulations in direct and reciprocal
space, with a mechanism involving only small atomic displacements 1.
Gummelt proposed a concept of non-pe1iodic coverings, with one "unit-cluster"instead of tilings composed of two or more "unit-cells"2. Applying that concept tostructure models of quasicrystal and approximant improves the transformation
mechanism proposed.
It provides new relevance for tiling-flip mechanisms on the cluster-scale as a tool

to study phason fluctuations. Monte Carlo simulations of continuously changing
cluster coverings and the respective diffraction .patterns are presented . Some ofthe outcomes shed new light on the transformation mechanism and on order I
disorder processes evidenced in diffuse scattering.
[ 1) Honal M. , et al., Acta Cryst, (1998), A54 : 374- 387.
[2) Gummelt P., Geometriae Dedicata, (1996), 62: 1 - 17.
Email : welberry@rsc.anu .edu.au

AB-8

ROLE OF AN'IWHASE BOUNDARY ENERGY IN PERIODIC TO QUASIPERIODIC
TRANSFORMATIONS IN SUPERIATilCES

U. D. Kulkarni, Materials Science Division, Bhabha Atomic Research Centre,
Trombay, Mumbai-400 085, India.
Results of the strip projection method have established that formation of planar
defects is the initial stage of a periodic to quasiperiodic (P to QP) transition. Whilethe crystal to quasicrystal transformation in certain systems initiates through theoccurrence of periodically spaced faults, antiphase boundaries (APEs) play asimilar role in periodic to quasiperiodic transformations in superlattices. Energyof the relevant planar defect is, therefore, expected to play an important role in
the occurrence of periodic to quasiperiodic transformations of either kind. In theMonte Carlo simulation carried out in this work, the change in APB energy,
accomplished by suitably altering the pair interaction energies, was found to
explain the diffraction effects observed in the course of the transition - fromperiodic Al 5Ti3 to a quasiperiodic superlattice structure to another periodic
structure Al 11 Ti 7 - observed in Al-rich single phase y-TiAl alloys with varying
compositions. The simulation results bring out salient features of the atomic
arrangements in imperfectly ordered quasiperiodic and nearly quasiperiodic
structures encountered in this transition.
Email : ulhasdk@barc.apsara.emet.in

AB-9
THE MULTIPLY 'IWINNED MODUlATED STRUCTIJRE OF TRIETiiYL PHOSPHINESULFIDE

Weenawan Somphona, Kenneth J , Hallera and A. David Raeb , aschool ofChemistry, Institute of Science, Suranaree University of Technology, Nakhon
Ratchasima 30000, Thailand.
bResearch School of Chemistry, Australian
National University, Canberra, ACT 0200, Australia.
The published structure (M. Van Meerssche & A. Leonard, (1959) Acta Cryst. 121053-1054) of S=P(C2H5)3 is described as having a 1:1 disorder in space group
P63mc with Z = 2 with P31 c describing a proposed ordered structure rather thanP63. Synthetic precession photographs obtained from data collection on a Nonius
CCD diffractometer clearly indicate a doubling of the a and b axes. The parent
P63mc structure can also be described as a C centred orthorhombic cell of Ccm21
symmetry with ap' = 2ap + bp, bp' = bp, cp' = cp with four molecules per cell.
The dominant modulation creating the extra reflections is a combination of
displacements parallel to c and not an ordering of the ethyl ligands. This mode
lowers the Ccm21 symmetry to Pnm21 with three fold twinning restoringh exagonal diffraction symmetry. Further modulations of the parent structure
seem necessary, with partial ordering in a mode of Pna21 symmetry is aThis s u ggests a probable six fold twinning since local
reasonable option.
symmetry of an average structure would then be lowered to Pn. Absences in thediffraction pattern suggest that the n glide is a dominant feature with adjacentlayers displacing in opposite directions a long c.
Email : rae@rsc.anu.edu .au

A9 : Cha rge den sity stud ies

A9-lCHARGE DENSI1Y DISTRIBUTION AND X-RAY ABSORPTION SPECTROSCOPY
OF ffiON-NITROSYL TlllOLATE COMPLEXES

I-Jui Hsu 1 , Gene-Hsiang Lee 2 , Chou-Fu Sheu 2 , Chung-Hung Hsieh3, Chiao-Chun
Chen 3, Wen-Feng Liaw3, and Yu Wang 1 . l. Department of Chemistry, National
Taiwan University, Taipei , Taiwan. 2. Instrumental Center, National Taiwan
University, Taipei, Taiwan. 3. Department of Chemistry, National Changhua
University of Education, Changhua, Taiwan
The biomimic tri- , di- and mono- nuclear iron-nitrosyl complexes formed from thedegradation of iron-sulfur protein are synthesized. The coordination sphere of Fe
in the trinuclear complex and in the mononuclear one can be described as atetragonal pyramidal Fe(NO)(S) 4 core . The dinuclear one consists of one dinitrosyl
local tetrahedral Fe(NOb(Sb core and one trigonal bipyramidal Fe(NO)(S) 4 core.
Electron density distributions of these complexes are studied in terms of amultipole model based on the X-ray diffraction data and are a lso studied by themolecular orbital calculations. Topological properties associated with the bondcritical points (BCP), Laplacian of the electron density as well as electron density
at the BCP of each chemical bond will be presented. The comparison between
experiment and theory will be made. The intra-molecular chemical bond as wellas the binding in the iron cores of trinuclear and dinuclear complexes will be
discussed. The binding interactions between two Fe atoms with short Fe-Fe
distance of 2.5772(3) A and 2 .6625(2) A are good examples of metal metalinteractions. The oxidation states and the net atomic charges of the Fe atoms aswell as the magnetic properties are also interesting aspects of these complexes.
The charge density investigation complimented by the X-ray absorption
spectroscopy is expected to lead to the understanding of such properties .
Email : choufu@taiwan.com

'

A9- 2

CHARAC1ERIZATION OF BR ··BR INTERACTIONS IN TWO POLYMORPHS OF 4BROMOBENZAMIDE CRYSTALS BY ELECTRON DENSITY DISTRIBUTIONANALYSES --- DATA COLLECTIONS ON A CONVENTIONAL IP WEISSENBERGCAMERA AT SPRING-S BL04B2 BEAM LINE

D. Hashizume, K. Tamakawa. Y. Nakasuji, M. Yasui and F. Iwasaki, Department
of Applied Physics and Chemistry, The University of Electro-Communications,
Chofu. Tokyo 182-8585, Japan.
Short Br···Br contacts have been observed in many organic crystals and attracted
great interests from the view point of the crystal formation . To elucidate theproperties of this Br···Br interaction, we attempted electron density distribution
analyses. 4-Bromobenzamide crystallizes into two crystalline forms (a- .(I) . and ~­form , (II)) . Both of them show short Br·· ·Br contacts, while directions of thesecontacts are different.
The diffraction data of' the crystals of these two-forms were collected at lOOK
using the IP Weissenberg camera, DIP-LABO, at BL04B2 in SPring-S withradiation of 37.8keV(0.3282A) to reduct absorptions of X-rays. An oscillation
In order to achieve highmethod was applied to the data collections.
completeness. some· data sets were collected with different crystal orientations.
Especially. for the crystal of (I). five data sets were collected for low and high angle
regions with different exposure time. The data were processed by the program
DENZO . Conventional and high order refinements were carried out by the
program SHELXL-97. Now we are carrying on the structure analysis of (I) by themultipole expansion method . Current results are as follows; Rrnt. R(F) , (sin8I A)max. reflections of I >2cr(I). unique reflections are 0 .072. 0.042. 1.0 , 6 0 70 and
5143, respectively.
Email : hashi@pc. uec.ac.jp

A9-3

ARE SQU.ARA'IE AND CROCONA'IE DIANIONS AROMATIC? AN EXPERIMENTAL
CHARGE DENSI'IY STUDY.

Anupama T. Ranganathan and G. U. Kulkarni'· Chemistry and Physics ofMaterials Unit, Jawaharlal Nehru Centre for Advanced Scientific Research ,Jakkur, Bangalore- 560 064, India.
The electronic charge density method of X-ray crystallography is employed to
study diverse aspects of molecular systems. A comparative study of thestructure and topography of charge density in the squarate and croconate
dianions has been carried out based on low-temperature X-ray diffraction
measurements. Both the dianion rings exhibit a high degree of planarity withuniform C-C bond lengths and angles typical of conjugated systems.
Accordingly, the bond critical points in the two dianions carry similar
densities as well as Laplacians. Deformation density maps reveal that thesquarate ring is more strained than the croconate. Both the rings exhibit (3,+ 1) ring critical points (RCPs). The density and the Lapl:=tcian associated with
the RCP of the squarate anion are 0.59 eA-3 and 11.8 eA-5 respectively, while
for the larger croconate ring, they are nearly one-half these values. RCP
parameters of the dianions have been compared with thos e of several
aromatic as well as non-aromatic cyclic systems from literature. A plot of the
Laplacian versus density at RCP of the squarate and the croconate dianions
along with other cyclic systems of different sizes shows how one candistinguish, aromatic and nonaromatic systems . The aromatic rings fall in aregion where the Laplacian is roughly proportional to the density while the
non-aromatics show no definitive trend. The plot may be useful in the case ofpolycyclic systems where aromatic and nonaromatic rings coexist.
Email : kulkarni@jncasr.ac.inA9- 4OBSERVATION OF TIIERMALLY EXCITED 4f-STATE AND MECHANISM OF
ELECTRON TRANSFER IN TIIE KONDO-CRYSTAL CeB 6 BY MULTITEMPERATURE X-RAY DIFFRACTION .

Kiyoaki Tanakaa and Y. Onukib, a Dept. Mat. Sci. & Eng., Nagoya Inst. Tech.,
Nagoya 466-8555, Japan. and bOept. Physics, Osaka Univ., Toyonaka, 560-0043,
Japan
E lectron density distributions (EDD) in rare-earth complexes have been supposed
to be a lmost impossible to measure by X-ray diffraction. However EDD in CeB 6 ishighly interesting since 4f-electrons are spontaneously transferred from Ce to B6
with a decrease in temperature by Kondo effect. Measurements at 298, 230, 165
and 100 K and a least-squares analysis assuming spin-orbit interaction for 4felectrons revealed thermally excited 4f-state at 298 K and essential nature of the·changing system beyond our expectation. It revealed that more 4f-electrons andB-2p electrons which contribute to B-B bonds within B 6 regula r octahedra atcorners of a cubic cell are transferred at lower temperature to B-B bonds
connecting B 6 octahedra. The localized electrons permit small but s ignificant
expansion of the outermost lying Ce-5p0 =3/2) orbitals and enhanced anharmonic
vibration (AHV) at low temperature. which explains the observed EDD quite well.
The enhanced AHV in one of the most closest-packed crystals corresponds to anincrease in entropy. Since the 4f-electron-transfer itself increases entropy, itcannot be stopped, though 4f-orbital becomes more stable at lower temperatures.
The first excited 4]- 7 orbital has significant electron population at 298K
corresponding to an energy gap of 4 70K and discontinu ou s change of crystal
structu re by it is a lso observed.
Email: kiyo@tan al.kyy .nitech.ac.jp

A9-5~~ 3- ~ \REFINEMENT OF CRYSTAL STRUCTURAL PARAMETERS AND
DENSTIY USING CONVERGENT-BEAM ELECTRON DIFFRACTION

CHARGE

M. Tanaka and K. Tsuda, Institute of Multidisciplinary Research For Advanced
Materials. Tohoku University, Sendai 980-8577, JAPANWe developed a new method to refine crystal structural parameters using
convergent-beam electron diffraction (CBED), which is applicable to nanometersize crystal structure analysis (K. Tsuda and M. Tanaka: Acta Cryst. A55, (1999)
939). The method is based on the fitting between theoretical calculations andexperimental intensities of energy-filtered tu:o -dimensional CBED patterns
containing zeroth-order Laue-zone (ZOLZ) and higher-order Laue-zone (HOLZ)
reflections.
The use of HOLZ reflections is essential for the present method
because small displacements of atoms can be sensitively detected using HOLZ
reflections with large reciprocal vectors.
For this purpose, we developed anenergy-filter transmission electron microscope (JEM-2010FEF) and an analysis
progran1 (MBFIT) to refine structural parameters based on the dynamicaldiffraction theory.
Using this method, we .have refined the atom positions and anisotropic DebyeWaller factors of the high-temperature phase of LaCr0 3 . Clear anisotropy of thethermal vibration of the oxygen atoms has been successfully detected by electron
diffraction for the first time. The low-order structure factors, which are sensitive
to valence electrons, were refined together with these structural parameters , andwere converted to deformation charge density. The result clearly s.h ows chargetransfer from La and Cr atoms to 0 atoms.

Email: tanakam@tagen.tohoku.ac.jp

B

CHARGE DENSTIY STUDIES BY THE MEM AND FLAPW

Masaki Takata, Hiroshi Tanaka*, Yoshihiro Kuroiwa#, Eiji Nishibori and Makoto
Sakata, Dept. of Applied Physics, Nagoya Univ., Nagoya, 464-8603, Japan, *Dept.
of Material Science, Shimane Univ., Matsue, 690-8504, Japan, #Dept. of Physics,
Okayama Univ., Okayama, 700-8530, JapanThe Maximum Entropy Method (MEM) is one of the powerful tools for the charge
density study of crystalline materials. By the development of the MEM/Rietved
Method , the new aspects of bonding nature for various crystalline materials havebeen revealed from synchrotron radiation powder data. In order to explore theorigin of the bonding nature, a comparative charge density study between the
MEM and the theoretical charge density should be one way to examine thecharacteristic feature of bonding electron distribution. In the talk, the charge
density studies of MgCu 2 , PbTi0 3 and BaTi0 3 by the MEM/Rietveld method andthe Full Potential Linear Augmented Plane Wave (FLAPW) method will bepresented to illustrate a usefulness of the comparative study of MEM and FLAPW
method.
In the MEM charge density of the Laves Phase, MgCu 2 , the strong covalentbonding was found for the Cu-Cu kagome network. which is characteristic closepacked atomic arrangement of the Laves phase structure. This characteristic
covalent feature was well reproduced in the theoretical charge density by the
FLAPW method and identified as the result of the hybridization of Cu(p3 d 3 ) orbital.
The results of the PbTi0 3 and BaTi0 3 will be also presented and discussed inconnection with other ferro-electrical properties.
Email: a41024a@nucc.cc.nagoya-u.ac.jp

eELECTRIC PROPERTIES OF CRYSTALS USING X-RAY DIFFRACTION.

N.K. Hansen, P. Alle, S . Dahaoui, P. Fertey and R. Guillot. Laboratoire deCristallographie et Modelisation des Materiaux Mineraux et Biologiques - CNRS
7036. Universite Henri Poincare - Nancy I, B.P. 239, 54506 Vandoeuvre-les-Nancy
cedex, France.
Single crystal X-ray diffraction measurements at ambient or low temperatures
allow obtaining an accurate description of the electron density distribution. We
have been interested in determining electric properties from such data formaterials with interesting electro-optical applications. The examples of
spontaneous polarisation and pyro-dectricity will be presented and we will
discuss limitations due to fundamental and practical problems . Only in certain
cases, will it be possible to give a rigorous definition of the spontaneouspolarisation based on the charge density. independent of how accurate this maybe.
A second part will concem diffraction measurements of piezo-electric coefficients.
We have constructed an apparatus allowing us to apply electric fields to single
crystals during the diffraction experiment. In order to minimise long-term
modifications of the defect structure of the sample due to the field, a crenel
shaped high voltage is applied. This technique is inspired by early work by Puget
and Godefroy (1975) and I. Fujimoto (1982) and others. Our first results showthat piezo-electric coefficients can be determined quite reliably from changes in
Bragg angles. In principle we may analyse structure and electron density
polarisations by measuring changes in the Bragg intensities. This is neverthelesshighly delicate because of problems with reproducibility of the minute inducedchanges.

Email: hansen@lcm3b .u-nancy.fr

A9-8

CHARGE DENSI'IY ANALYSIS OF 5-FLUOROURACIL AND 1,3-DIMETHYL-5FLUOROURACIL

Partha:pratim Munshia, M. D. Prasannaa. T. N. Guru Rowa, P. R. Mallinsonb arid
A. Coetzeec, asolid State and Structural Chemistry Unit, Indian Institute of
Science, Bangalore 560012 , India, bDepartment of Chemist1y, University ofGlasgow. Glasgow Gl2 8QQ, UK. cNonius B. V.. P. 0 . Box 811, 2600AV Delft, The
Netherlands.
Molecular recognition, self-assembly of complex molecules, coordination
cnemistry and generation of nucleotide structures are governed by weakintermolecular interactions. The study of interactions involving fluorine is ofparticular interest because of the unusual behavior of 'organic fluorine' inaccepting hydrogen bonds. The charge density distributions in crystals of 5fluorouracil and 1,3-dimethyl 5-fluorouracil have been analyzed using highresolution X-ray diffraction data at lOOK. 5-fluorouracil has dominant N-H ... 0
C-H ... F and C-H ... O
interactions along with several weak C-H ... O bonds.
interactions contribute to the packing in the crystal structure of 1,3-dirnethyl 5fluorouracil. Both structures have been evaluated in terms of critical points
properties , Pb and Laplacian (V' 2 p) distribution. C-H ... F interaction appears in the
structure of l ,3-dimethyl 5-fluorouracil indicating that the methyl substitution
masks the propensity for the formation of strong N-H ... O bonds present in the
structure of 5-fluorouracil.
Email: munshi@sscu.iisc.en1et.in

·-

A9-9

X-RAY AND NEUTRON DIFFRACTION STUDIES OF SHORT SINGLE WELL N-H-0
AND N-D - 0 HYDROGEN BONDS

Samuel M-F. Loa. Fanny L-Y. Shek. a Ia n D. Williams,a Judith A.K. Howard,b John
aDepa rtment of Chemistry,
Hong Kong University of Scien ce and Tec hnology, Kowloon , Hong Kong.
bDepartment of Chemistry. University of Durha m. Durham, U.K. crnstitut LaueLangevin, Grenoble. Fr ance.

A. Cowa n ,b.c Garry J . Maclntyre. c Sax A. Masone

Short single well N-H-0 hydrogen bonds a re of considerable physical andbiological interest. We have investigated those found in the mixed crystal 2 [4.4'bipyHo.5HCGH2-l.2.4.5-(COOkH3l a nd in dinicotinic acid [C 5H 3N-3.5-(COOb-H 2]
by variable temperature X-ray and neutron diffraction . The N- -H--0 distances are
between 2.50 a nd 2.55A and change only slightly with temperature. However the
position of the hydrogen atom shows considerable temperature d e pendence with
N-H ca. l.2A and 0-H 1.3A at 20K a nd the r everse holding for room temperature.
This a pparent 'proton translation' could be interpreted as due to the asymmetry
in the H-bond potential well. To study this furth er large deuterated crystals ofdinicotinic acid were prepared hydrothe rma lly u s ing d euterium oxide as solvent.
This showed a lengthening of 0.04A in the N---0 distance and an even greatertemperature depend en ce of the N-D and 0-D le ngths compared to the protio
analogue. These novel findings contravene the conventional model of deuteration
effects on low-barrier hydrogen bonding.
Email : samuello@ust.hk

CHARGE ORDERING AND VALENCE-CONTRASTED DIFFERENCE-FOURIER
MAPS IN Eu3S4

Satoshi Sasaki, Hiraki Ohara and Yukiko Konoike, Materials and Structures
Laboratory. Tokyo Institute of Technology, Nagatsuta 4259, Midori, Yokohama
226-8503, Japan.
Eu 3S 4 is a mixed-valence compound that has divalent and trivalent Eu ions in theinteresting example of the electronic arrangement andv ratio 1 : 2 and present antransport property. Synchrotron X-ray anomalous scattering technique wasapplied for the valence-di!Ierence contrast in the vicinity of Eu L11 absorption edgein order to determine the crystal structure and charge-ordering scheme for a lowtemperature phase of Eu 3S 4 . A vertical-type four-circle diffractometer was used
for single-crystal work at wavelengths of A.= 1.63116 and 1.62977 A in thebeamline BL-10A, Photon Factory. J a pan. The temperature dependence of 400,
040 and 004 intensities clearly showed that a room-temperature phase having abee Th 3P 4 structure (a= 8.516 ± 0.002 A} transforms to a tetragonal I4-2d cellr (e/a = 1.004} at 188.5 K. The charge ordering was determined from the VC\riationof residual factors in the least-squares refinement with a large difference inatomic scattering factors between Eu2+ and Eu3+. The result indicated that the
4a site is occupied by only Eu3+, while the 8d site is occupied by Eu 2 + and halfremained Eu3+. The existence of charge ordering was also supported by thedifference-Fourier syntheses assumed that either Eu 2 + or Eu 3+ ions occupy all Eu
sites.

I

Email: sasaki@n.cc.titech.ac.jp

A9-llA CHARGE DENSnY S11JDY OF XYLITOL AND RIBO'IYL, 1WO PENTOSEEPIMERS

S. Larsen and A. 0. Madsen, Centre for Crystallographic Studies, University of
Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
The two pentose isomers x:ylitol and ribitol differ significantly in their physicochemical properties. Xylitol which crystallises in the acentlic space group P2 12 12 1
is the higher melting, whereas the lower melting ribitol belongs to the centric
P2 1/c. We have performed a determination of the crystal charge density of the twocompounds using high resolution X-ray diffraction data in order to elucidate thedifferences in crystal structures of the two pentoses. High resolution (sin 8/A.<l.lA) X-ray diffraction data have been measured on both compounds. To obtainreliable parameters for the hydrogen atoms and investigate the deconvolution ofthermal motion from the X-ray diffraction data, neutron diffraction data were
measured at ILL. A topological analysis of the crystal charge density was
conducted in order to unravel differences that can explain the different physicochemical behaviour of the two pentoses. The analysis included a determination of
the atomic basins defined by the zero-flux surfaces in the electron densities thatwas used to determine integrated properties of the atoms in the two compounds.
Email : sine@ccs.ki.ku.dk

A9-12A COMBINATION METHOD OF CHARGE DENSITY MEASUREMENT IN HARD
MATERIALS USING ACCURATE , QUANTITATIVE ELECTRON AND X-RAY
DIFFRACTION

Victor A. Streltsova, Philip N. H. Nakashimaa.b and Andrew W. S. Johnsonb,acrystallography Centre. Department of Physics and bCentre for Microscopy.
University of Western Australia, 35 Stirling Highway, Crawley WA 6009,
Australia.
Current X-ray diffraction techniques for commonly imperfect specimens provide
structure factors only on a relative scale, and the kinematic scattering condition
breaks down for strong low Bragg angle reflections. Multiple diffraction is
accounted for accurately in quantitative convergent beam electron diffraction(QCBED) data analysis, which provides absolutely scaled structure factors.
Conventional single crystal X-ray diffraction has proved adequate in softer
materials where crystal· perfec tion is limited. In hard materials, the high ly perfect .
nature of the crystals is often a difficu lty. This is due to the inaccuracy of thecorrections conventionally used to account for multiple scattering (extinction). The
combination of accurate QCBED and X-ray diffraction structure factors provides
more reliable analyses of experimental charge density in hard materials. The
precision of the combination method is such that it promises to distinguishbetween rival many-electron theories used for structure calculations.
Our present study exploits the complementarity of synchrotron X-ray
measurement for weak and medium intensities for cx-Al 2 0 3 . and QCBED
measurement of the strong low-angle reflections . The consistency of the QCBED
structure factors determined from independent data sets at various accelerating
voltages. thickness. and orientations and matched by both the Bloch-wave anq
th e mtJlti-slice methods confirms the validity of the technique.
Email: strel@crystal.uwa.edu.au

A9-13

TOPOLOGICAL ANALYSIS OF NH 4 [Ti(C 2 0 4 ) 2 ]•2H2 0

Yen-Chen. Lin 1, Yi-Hung Liu2, How-Shuenn Sheu 3 . Yu Wang 1 . l. Department ofChemistry, National Taiwan University, Taipei, Taiwan. 2. Instrument Center,
National Taiwan University. Taipei, Taiwan. 3. Synchrotron Radiation ResearchCenter. Hsichu, Taiwan.
High coordination number complex. NH 4 1Ti(C20 4 ) 2]•2H 20, is reinvestigated. EachTi atom is coordinated by four oxalate dianions with a coordination number ofeight in an approximate symmetry of D4 geometry. Electron density distribution ofthis complex is studied in terms of multiple model based on the x-ray diffraction
data. A theoretical calculation based on the periodic density functional theory(DFT in CRYSTAL98 program) will be reported for comparison. The result obtained
from multipole refinement shows that the d:z2 orbital is the most populated
among all five d orbitals of Ti. Topological properties associated with the bondcritical points (BCP). Laplacian of the electron density as well as electron density
at the BCP of each chemical bond will also be presented. The BCP of C-0 bond isapparently more positive closer to the carbon atom than to the O:>-..)'gen atom. The
delocalization of the oxalate ion will be demonstrated by the Fermi-hole function
and the theoreticalvalue. The isovalue surface of Laplacian for such a eightcoordinated Ti metal will be displayed .
.Email : sirius8@saturm.seed.net. twAlO : Edu cati on, co111puting anddat aba ses

Al0-1
A DATABASE ON CRYSTALLOGRAPIDC AND MECHANICAL PROPERTIES OFPOLYMERS

Amjad Basha, Anjana Jain and Kalyani Vijayan, Materials Science Division,
National Aerospace Laboratories, Bangalore 560 017, India.
It is well known that the properties of a material are closely related to the crystal
structural characteristics. In this context, it is useful and convenient to compile
together the crystallographic and other properties of interest. Polymers play animportant role in aerospace engineering. A database entitled 'POLYSEARCH' has
been developed to compile the crystallographic and tensile characteristics ofpolymers used in aerospace.
Details of the properties at ambient, high. low temperatures and high pressures
are included . A category on miscellaneous properties such as glass transition,
melting, decomposition temperatures, recommended limit of service temperature,density, names of suppliers etc., has also been included. POLYSEARCH is a userfriendly database with multiple access to any polymer. The package ChemSketch
has been used to display the chemical and the molecular structure.
Email: kavi@css.cmmacs.emet.in

Al0-2EMPIRICAL SUGAR BINDING SITE PREDICTION

Clara Shionyu, Tsuyos hi Shirai. and Tal<ashi Yamane, Department of
Biotechnology and Biomaterial Chemistry. G rad u ate School of E1 1~ in eer ing.
Nngoya University.
C;1rbohydrate - protein interactions are known to take part in <1 variety ofbio logical activities . including cell t-eco<in ili on, growth control a nd apotos is.
Detailed knowledge of structure based carbohydrate - protein in terani ons can beextracted from three-dimensional structures. To d ate, several lens of threedimensional stnJctures of carbohyclratye - protein complexes have been
determined. Considering the importa nt roles of carbo hydrate in Lh e life system ,the current methods in bioimfomatics and structural biology for carbohydrates
are still immature.
We are deve loping a computer program syslem. which predict sugar b inding site
on protein 3D structures. This program system searches for the pos ition or sugar
binding sites by referring to empirical rules that are derived from known 3D
structures of sugar-protein complexes . The system consists of programs forconstruction of empirica l rules (scoring system) a nd programs for sugar bindingsite search. A total of 192 non-redundant sugar-protein complex structures wereselected from PDB for empirical rule construction. The system was tested on
several known sugar-protein complexes. Sixty-nine percent of the known primarysugar binding sites were successfully predicted.
Ema il : clarp,_s@mbox.media.nagoya-u.ac.jp

Al0-3
MOLECULAR REPlACEMENT IN HEMIHEDRAL 1WINNING

Hiroyuki Ka nd an.b, Ta k ashi Kum asakab, Kensaku Hamadaa.b . Masaki Ya m a mot o'·.
Masashi Miyanob. nrnterdisciplin ary Facully of Science and Engineering. Shimattc
University. Nis hikawatsu, Malsue, Shimane 690-8504 J apan, hRIKEN Ha rirn a
Ins titule. Mikazuki. S ayo. I-Iyogo 679-5148. J a pa n .
Crysta l twi nning is ra rely observed and causes diffi cully in a n a lyzing crysl<llstru ctures. Especially, m e roh edra l tw inning that all refl eclions overla p wilh t lit 'other twin components is troublesom e . However. when th e crystal co ns ists of jus L
two components a nd the twin fraction is n ot equal to 0 .5 (pa rti al twinning), theintensity of each of components can be retrieved by con s id e ring the diffe ren ce ofthe contlibution to the difJi-action inte nsity . If th e value of th e twin fraction is
given , it is possible to restore the individual inten s ities by solving a set ofsimultaneous equ ation including the twin fraction a nd inte n s ities . Unfortun a lely.
the solutions of the simultaneous equation will b e degen era ted in the case ofp erfect twinning (i. e. the twin frac tion is just equ al to 0.5) . a nd they ca n 't be
separated. In this study , a molecular re placem en t program (AlVIoH.e) is modified ~othat it can solve the structure even in th e case of perfect twinning. Since iL is
impossible to separate a reflection into each of components in the rotation
fun ction for perfect twinning, the m odifi cation was m a d e on ly to th e translation
function. The outline of the ch a n ged a lgorithm a nd th e rcsulL of the app lica ti on
for a mod el d ata set will b e reported .
Email : sukeroku @spring8 .or.jp

AI0-4
TITAN2000: A PROGRAM TO AID STRUC'IlJRE SOLUTION AND REFINEMENTWITII TIIE SHELX SUITE OF PROGRAMSJim Simpson and Keith A. Hunter, Department of Chemistry. University of Otago,
P.O. Box 56, Dunedin, New Zealand .
The TITAN2000 program has been developed as a readily accessible tool to giveclasses of undergraduate students experience of the solution and refinement ofsmall molecule crystal structures. It also has applications for crystallographers
who do not have facile access to SHELX based molecular graphics programs. The
program has been upgraded to run in the Windows 95/98/2000 or NT
environments and provides a shell from which to launch the SHELXS 1 (solution)and SHELXL2 (refinement) programs. such tha t the complete structuralcharacterization can be accomplished within the program.
The program has evolved to provide an easy to use and relatively intuitive tool forthe display and manipulation of output from the SHELX programs. This
presentation will incorporate a demonstration of the operation of the program andwill highlight features of the program from a teaching perspective.
l.

Sheldrick, G.M. (1990) SHELXS A program for the solution of crystal
structures from diffraction data. University of Gottingen, Germany.

2 . Sheldrick, G.M. (1997) SHELX.L-97 A program for the refinement ofcrystal structures . University of Gottingen. Germany.
Email : jsimpson@alkali.otago.ac.nz

AI0-5
SAMR-WEB: A SEMI-AUTOMATIC GRAPiflCAL USER IN1ERFACE PROGRAMFOR THE MOLECULAR REPlACEMENT METIIOD
K. Nozawa and K Hamada, Interdisciplinary Faculty of Science and Engineering,
Shimane University, Matsue 690-8504, Japan.

We have developed a graphical user interface program SAMR-Web which was
designed as Internet-based tool for protein structure solution by the molecularreplacement method (MR) . The software is linked to Web sites of the Protein Data
Bank (PDB) and the Swiss Model being an automated protein modeling server.
Candidates of the model structure are searched in the PDB or the ExNRL-3D witha query sequence and an atomic coordinate of the search model including side
chains is made by the comparative protein modeling method. The SAMR- Web thenmakes input data required for execution of the EPMR or AmoRe which aremolecular replacement programs. The GUI is implemented in standard Perl andhas been tested under Linux Redhat 6.2. The SAMR-Web required only minimaluser inputs. including space-group symmetry, unit-cell parameters, reflection
data and sequence file names and the number of copies of the search model in theasymmetric unit.

Email: hamadak@cis.shimane-u.ac.jp

Al0-6
THE SEARCH/MATCH SYSTEM FOR POWDER DIFFRACTION DATA

Zhang Mingtao, Zhuo Dongtao, Li Jie, Qiao Yuanyuan, Lin Sh aofa n(Cen tral
La boratory, Nankai Universi ty, Tia nJin 300071 , China)
A new method for id entifying components in crystalline mixtures from their X-ray
powder diffraction data is pres ented. It can b e run in Windows-9X. The referen ce
database comes from the powder diffraction files (PDF) provided by the JCPDSlntemational Centre for Diffraction Data.
This m ethod uses the weight factor for each diffraction peak as a c riterion, a nd
can not only give a list of poss ible phases but a lso the definite components of th e
unknown sample by a simulation process. Actual samples have been tested withhigh p erforma n ce . The k ey points in th is system a re:l. To compare the sample d ata with the d ata b ase to make two filtrating- -threemost intensive peaks fi ltering a nd element fil ter ing. The phases which passfiltrating were conceded as possible phase existed in the sample (Selected Phases).
2 . Our program uses those SELECTED PHASES as the basic units to s imul ate th esample p attern with various combinations . Appearance of complete combination sby different m ethods would indicate real compon e n ts of the sample.
3. Evaluation of the simulated pa tte rns: The compon ents of th e s imu lated
pattern , which has high est SIMILARITY, would b e the co mpon ents of the sam ple.

Email : Linsf@centla b.na nkai. edu .cn

Al0-7

AB INmO MO STUDIES ON TIIE ELEC1RONIC S1RUCTURE OF GLYPHOSATE.

P. Ka li an n <l n and M. Mohamed Naseer Ali. Department of Physics. Bharathidasan
Unive rsity. Tiruchirappalli - 620 024 , INDIA.
The h erbicidal markets d em a nd high p erform ance products with stringent
e nvironme ntal acceptabili ty requirements. Enzyme inhibition techn ique is one
approach to meet out th ese c ha ll e nges. Effective plant specific e nzyme inhibitors
offer t h e opportunity to satis fy th e h erbicide performance n eeds of the m a rkets
pbce wh il e exhibiting favourably low mamma lia n toxicity properties. An attractive
l'tJ zy me sys tem on which to test thi s a pproach is EPSPS (5-enolpyruvyl shikimate- J - phos pha te synthase) wh ic h is the target for N- Phosphono methyl glycine(g lyphosate). Glyphosate is a non-selective h erbicide that controls most of th eworld's worst weeds while exhibiting very low mammalian toxicity. In order tomodel a better inhibitor for this ta rget enzyme we a re in n eed of the d etailed
structural studies of the t ernary complex of this e n zyme . In the pres ent study a neffort is mad e to a n a lyse the conformation al features of glyphosate using
quantum c h emical calcula tions.
We h ave ca rried out a detailed ab initio MO calculation s for this inhibitor as a n
initi a l s te p. Th e conform ation a l en ergies, structural t rends and exact locations ofco nform ers in torsiona l space a re studied at the HF level of th eories with different
bas is s et. We h ave a lso cons tru cted t h e potential en ergy surfaces for glyphosate.
The results of Mu lliken population analysis a nd the behaviour of glyphosate in its
to rsional space will b e discussed.

Email : nasee r@bdu. ern et.in

Al0-8DEPOSmON AND PROCESSING OF PR01EIN DATA BANK ENTRIES AT OSAKAUNIVERSITY

M. Kusunoki, T. Kosada, R. Igarashi, Y. Kengaku , G. Kurisu and H. Nakamura,Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita. Osaka
565-0871, JapanThe Protein Data Bank (PDB) is the sole international repository for three dimensional structure data of biological macromolecules and is managed by the
Research Collaboratory for Structural Bioinformatics (RCSB) . USA. The RCSB is a
consortium composed of Rutgers University. the National Institute of Standards
and Technology, and the San Diego Supercomputer Center.
The coordinates of a biological macromolecule determined by X-ray
crystallography or NMR spectroscopy are deposited with the PDB by the authors.
The deposited data are validated and annotated by the PDB staff and are thenreleased to the scientific community over the Internet (http :/ /pdb.protein.osakau .ac .jp/) . The Institute for Protein Research. Osaka University. Japan has started
to serve as the deposition and processing center of PDB entries on July 1, 2000
for crystallographers and NMR spectroscopists in Asian and Oceanic regions.
Since then, we have collected and processed 349 PDB entries as of August 14,
2001. We operate the ADIT (http :/ /pdbdep.protein.osaka-u .ac.jp/). a Web-based
PDB input tool.+ the same one used by the RCSB. We will describe our archiving
activities of the PDB. The PDB activities at Osaka have been supported in part by
Japan Science Corporation.
Email: kusunoki@protein.osaka-u.ac .jp

Al0-9A STATISTICAL AND MOLECULAR-MECHANICS ANALYSIS OF TilE EFFECTS OF
CHANGING DONOR 'IYPE ON BOND-LENGTII TilE 1WO SERIES [Coll1Nn06-nl
AND [NillNn06-nl (n = 0- 6): A NEW ROUTE TO BOND-STRETCH PARAMETERS.

Rosalie K. Hockinga and Trevor W. Hambleya. acentre for Heavy Metals Research,
School of Chemistry, University of Sydney, Sydney. NSW 2006, Australia
Changes in bond lengths across the series of complexes [Co 111 Nn0 6_nJ and[Nil1Nn06-nl. (n = 0 -6) have been examined by a statistical analysis of the bondlengths in 256 Co 111 and 205 Nill complexes. In both cases a systematic reduction
in both metal-N and metal-0 bond lengths is observed as oxygen donors replace
nitrogen in the coordination sphere. In the case of Colli, the reduction in bondlengths is linear across the series. whereas in the case of Nill, the redliction inbond-lengths is more asymptotic in nature. The trends across the two series werereproduced using molecular mechanics, however, the magnitude of the change
was not initially predicted correctly in either case. Alterations to molecularmechanics parameters that reproduced the trends in the [Co 111 Nn0 6_nJ series also
resulted in an overall improvement in the predictions of CoiiLN bond lengths in aseries of Colli hexaamines. This improvement was taken as an indication that thebond-length reduction across the series is probably steric in origin.
Thesystematic change to the strain in these systems enabled a map to be made of theenergy surfaces describing the four interactions Ni 1LN, Nin-o. Co 111 -N and Co 111 -0 .
We find that many of these potentials exhibit an asymmetric character n everbefore seen experimentally, and believe that this new method of determining bondstretch parameters may give molecular mechanics an improved reliability forpredicting both structures and reactivity.
Email : hockin_r@chem. usyd.edu .au

Al0-10
EFFECTIVE USE OF HOME PCS IN ADVANCED CANCER AND AID RESEARCHPERSONAL EXPERIENCE.

S .Natarajan, Former Dean, Anna University.Chenn a i-60025 .Res . 34/1 S econd
Ma in Road. Kottur Gardens. Chennai-60085 .India.
In the era of drug design and macromolecular Crystallography the n eed rr11·
exte nsive use of computers is known to everybody. INTEL sponsored a programme
to tap the potentials of home PCs all over the world and it is doing wonderfully
well. As a retired teacher in crystallography I h a ve volunteered my home PC for
this purpose . There is a need to get more volunteers for this kind of projects 8 11
over the glob . In this regard my experience during the last few months under thi s
project will be presen ted/shared .
Email : ra darajan@eth.net

Al0-11APPUCATION OF ll ij MAPS

R.Sreekanth and S.S.Rajan. Department of Crystallography and Biophysics.
University of Madras. Chennai-600 025,India.
A few n ew methods were earlier proposed from this laborat01y (Srinivasan. R..
Balasubramaniam, R. and Rajan. S.S . 1975) with a view to extract information on
the nature of folding of protein chain and to analyze the distortions in helices
present in the protein . The helica l parameters for different stretches can a lso befound using these methods (Rajan, S .S. and S1inivasa n, R.1977) . These h ave now
b een applied to proteins solved at different resolutions to find the impact ofresolution on the helical parameters and distortions in different helices. S tudies
were a lso made on th e protein. lysozyme. solved at different humidity conditions
to find the effect of humidily on helical paramete rs. The details will be presented .
References:••

Srinivasan R..Balasubramaniam R. and Rajan S.S.(l975).J .Mol.Biol., 98 ,739.
Rajan. S.S. and Srinivasan. R. (1977). Biopolymers, 16, 1617.

Email: ssrsai@hotmail.com

AIQ-12ONTOWGIES: ROSETTA STONES FOR GWBAL KNOWLEDGE BASES

S.R. Hall, N. Spadaccini, D. du Boulay and I.R. Castleden, Crystallography Centre
and the Department of Computer Science & Software Engineering, The UniversityofWestem Australia, Perth, Australia 6009.
Phenomenal improvements in instrumentation have made the efficient processing
and communication of data one of our highest priorities. A key objective is thecapture of computer-interpretable "knowledge" (i.e. meta-data) . This is currently
achieved in crystallography using customised software packages. From a longerterm and global perspective such approaches are restrictive in that, they are
relatively inflexible (targeted at specific methodologies); non-extensible (new datatypes · cannot be added easily) and the embedded knowledge is neither humanaccessible nor re-useable (the meta-data are encrypted in imperative languages).
This talk will describe a generic object-oriented approach[1] to coalescing metadata into textual data dictionaries (i.e. ontological descriptions) . Some of themeta-data are methods and expressions that represent complex relationships
between defined data items. These dictionmies may be compiled into computercode and used as an executable knowledge kemel for data manipulation,
validation and interpretation.
A prototype crystallographic ontology, based on the widely adopted Core CIF
dictionary, will be used to demonstrate the evaluation of quantities such as
molecular geometry and structure factors.
[1] Spadaccini, N., Hall. S .R.. and Castleden , I.R. "Relational Expressions in STAR
File Dictionaries" 2000 J Chemical Information and Computer Science 40, 12891301.
Email : syd@crystal. uwa.edu.au

Al0-13
HYDROPHOBIC IN1ERACTION BE'IWEEN THE SUGAR MOIETIES OF
CARBOHYDRA1ES AND AMINO ACIDS IN GLYCOPR01EINS AND GLYCANBINDING PR01EINS

T. Hema Thanka Christlet and K. Veluraja, Department
Manonmaniam Sundaranar University, Tirunelveli 627 012, India.

ofPhysics ,The carbohydrate-protein interactions in glycoproteins and glycan-binding
proteins have been studied using the Protein Data Bank. The hydrophobic
interaction between the hydrophobic plane in sugars, formed by three axial
hydrogens in the stable chair conformation (pointing the same direction in ~­sugars of Glc, Gal, Man), or the methyl group of acetamide sugars (NeuNAc,
GlcNAc, GalNAc) and the hydrophobic/aromatic amino acids were computed. It isnoted that in more than 50% proteins there is stacking/hydrophobic interaction
between the glycan and the hydrophobic/aromatic amino acids. The angle
between the stacking planes is in the range of 30"±10" or 80"±10" indicating thespecificity of the stacking interaction. The methyl group in acetamide sugars also
takes part in hydrophobic interaction with the hydrophobic/aromatic aminoacids. To find the potentiality of various amino acids involved in hydrophobic
interactions, a quantity called hydrophobic interaction index (HII) is computed forthe two types of hydrophobic interaction. HII is maximum for Trp in bothglycoproteins and glycan-binding proteins when the hydrophobic sugar plane isinvolved in the interaction. Leu shows lower HII in glycoproteins due to the factthat Leu residues do not occur frequently at the surface of the protein and thecommon occurrence of glycosylation is at the surface . The high HII value for Leu
in glycan-binding proteins can be attributed to the predominant occurrence of
Leu at the interior of the protein and extended binding site for the glycan inglycan-binding proteins. Ala and Val have high value for HII in glycoproteinsbecause amino acids with small side chains are preferred around the N- and 0glycosylation sites . When the methyl group of acetamide sugars is involved HII is
maximum for Trp and Leu in glycoproteins and glycan-binding proteins
respectively. Thus it is concluded that stacking/hydrophobic interactions are oneof the important and highly specific stabilising forces in the case of carbohydrateprotein interactions.
Email: bio@md3 .vsnl.net.in

Author IndexAbell, C.
Abraham, E.G.
Achary, S.N .
Adachi , N.
Addlagatta, A.
Agarwal , N.
Aggeler, R.
Ahmed, S.A.
Ajees, A.A.
Alagar, M.
AI-Farhan, K.A.
Ali,M.M .N.
Aile, P.
Alshahateet, S.F.
Ambalavanan, P.
An, J.
Anderson, B.F.
Aonoa, M.
Aravinda, S.
Arnold, E.
Arnold, G.F.
Arockiasamy, A .
Asaka, T.
Asthana, A.
Aswal, V.K.
Ataka, M.
Saba, I.
Babu, C.R.
Bahadur, P.
Baker, E.N .
Baker, H.M.
Balaram, M·
Balaram, P.

Balasundaresan , D.
Bamzai, K.K.

Bandyopadhyay, A.

A6-105
A6-15
A3-14
A5-36
A6-115
A4-6
A6-64
A4-11
A1-1
A6-56
A4-37
A10-7
A9-7
A4-52
A4-32
A6-54
A6-6, A6-25
A2-5
A6-87
A6-34
A6-34
A6-68, A6-86
A3-20
AS-4
A6-31
A6-99
A4-68
A6-3
A6-31
A6-6, A6-18,
A6-19, A6-25
A6-19
A6-36, A6-90,
A6-91, A6-92
A6-36, A6-87,
A6-90, A6-91,
A6-92
A6-81
A5-8, A5-31 ,A5-33 , A5-35,
A5-41
A6-87

Banerjee, A.
Banerjee, S.
Banurekha, R.
Sao, H.
Barracough, P.
Bartlam, M.
Basak, A.K.
Basha, A.
Bauer, J.A.K.
Begum, N.S.

Begun, J.
Behera, R.C.
Sera, A.K.
Betzel, C.

Bhadbhade, M.M.
Bhagwat, M.
Bhanumoorthy, P.
Bhat, S.V.
Bhattacharya, S.
Bhavani
Bhawal, S.M.
Bhowmick, K.
Bilgrami, S.
Bilyk, A.
Binbin , L.
Bishop, R.
Biswal, B.K.
Biswas, S.
Blundell, T.L.
Bobet, J.-L.
Boulay, D. du
Brannigan, J.
Brinda, K.V.
Brink, F.
Cai , J .
Cai , L.-R .

A6-4, A6-5
A4-57
A6-41
A6-54
A6-123
A6-13, A6-54 ,A6-97 , A6-123
A6-2
A10-1
A4-50
A4-11 , A4-12,
A4-13, A4-14 ,A4-15, A4-48,
A4-47
PL-2
A3-3
A6-5
A6-58 , A6-61 ,A6-94 , A6-1 00,
A6-112, A6-113
A4-42
A7-5
A6-37
A6-10
A6-4, A6-5
A6-41
A4-65
AS-6
A6-94
A4-10
A6-55
A4-52
A6-7, A6-88
A6-78 , A6-95
A6-105
A?-7
A 10-12
A6-12
A6-43
AS-5
A4-28
A4-23

Caine, J.M.
Cao, R.
Cao, z.
Capaldi, R.A.
Castleden , I.R.
Catimel, B.
Centore, R.
Cha, J.A.
Chakrabarti, C.
Chakrabarti, P.
Chakraborty, S.
Chandra, A.
Chandra, M.
Chandra, N.R.
Chandra, V.
Chang, S.-L.
Chang-Chien, G.-P.
Chantrapromma, S.
Chao, C.H.
Chaplet, S.L.
Charnay, R.
Chatake, T.
Chatkon, A.
Chatterji, T.
Chaudhary, S.K.
Chaudhuri, N.R.
Chauhan , V.S.
Chen, C.-C.
Chen, C.-H.
Chen, C.-Y.
Chen, X.
Chen, X.-M .
Chen, Y.
Cheng, M.
Cheng , S.Y.
Chiba, H.
Ching, C.H.
Chinnakali, K.

PL-2
A6-118
A6-97
A6-64
A10-12
A6-11
A4-56
A4-24
A6-33, A6-95
A6-77
A6-4, A6-5
AS-3
A6-12
A6-26, A6-71
A6-94, A6-112,
A6-113
A1-5, A1-6,
A 1-7, A1-8
A4-56
A4-30
A1-5, A1-6,
A1-7
A3-1, A3-12,
A3-13, A3-14
AS-7
A6-65
A4-8
AS-39
AS-6
A4-62
A6-85
A9-1
A4-28
AS-17
A6-118
A4-28
A6-13, A6-54
A6-123
A1-8
AS-15
A1-6
A4-30

Chitra, R.
Choodamani, C.
Chou, C.-C.
Choudhury, A.R.
Choudhury, D.
Choudhury, N.
Choudhury, R.R.
Chaurasia, N.C.
Chowdhury, K.
Christlet, T.H.T.
Clarke, A.E.
Coetzee, A.
Cole, A.
Conesa-Moratilla, C.
Cowan, J.A.
Craig, D.C.
Dahaoui , S.
Damodharan, L.
Dasgupta, J.
Datta, A.
Datta, S.
Dattagupta, J.K.
Dauter, M.
Dauter, Z.
Dave, C.G.
Davidson, D.J .
Davis, T.J.
Davydova, N.L.
Deepthi, S.
Delft, F.V.
Desai , C.F.
Desai , S.S.
Deshmukh, A.R.A.S.
Deva, T.
Devarajegowda, C.
Dey, K.R.
Dey, S.
Dhar, P.R .
Dhar, S.N.
Dharmalingam , K.
Dhawan, U.
DineshA3-16
A4-35, A6-41
A6-20
A4-4
A6-78
A3-12, A3-13
A3-16
AS-34
A6-49
A10-13
A6-48
A9-8
A6-2
A7-4
A9-9
A4-52
A9-7
A6-50
A6-33
A2-3
A6-71, A6-88
A6-33, A6-95
A6-42
A6-42
A6-57, A6-106
A7-7
A2-9
A6-110
A6-89
A6-105AS-34
A2-1, A2-2
A4-65
A6-79
A4-48
AS-21
A6-111
AS-31
AS-34
A6-79
A7-10
AS-32

Dineshkumar, T.K.
Ding , J.
Ding , Y.

Dmitrienko, V.E.
Doan, D.
Dodia, N.
Dodson , G.
Dodson , G.G.
Oakland, T.
Dong , B.Z.
Dong , S.
Dong , Y.
Dongtao, Z.
Duax, W.L.
Duke, N.
Dunlop, J.
Eaazhisai , K.
Easton, C.J.
Edwards , R.A.
Eggleston , D.S.
Engel , G.
Eswaramoorthy, S.
Fan, J.
Fang, P.S.
Farina, Y.
Fei , S.
Fertey, P.
Fontes, M.R.M.
Forouhar, F.
Friese, K.
Fujii , T.
Fujii , Y.
Fujimoto, Z.
Fukuda, Y.
Fukuyama, K.
Fun , H.-K.

Ganesh, N.

A6-27
A6-34
A6-13, A6-23,
A6-54, A6-97,
A6-118, A6-123
A3-9
A6-102
A6-52
A6-12
PL-4
A6- 102
A5-12
A5-9
A6-54
A10-6
A6-115
A6-97
A4-10
A6-36
A1-2
A6-6, A6-25
A6-76
A7-4
A6-59
A6-16
A1-8
A4-68
A6-117
A9-7
A6-11
A6-20
A8-5
A6-120A1-4, A3-19,
A5-42, A6-29 .
A6-2Q , A6-125
A2-1 2
A6-45
A4-30, A4-33,
A4-54, A4-55,
A4-68
A6-71

Ganggang , W.
Gao, D.
Gao , F.
Gao , Y.
Gautham , N.
Gayathri , V.
Geisler, S.C.
Geng , B.
Genov, N.
Geue, T.
Ghosh , S.
Girija, C.R.

Goddard , R.
Gael, M.
Gael , V.K.
Gonnade, R.G .
Gopalakrishnan, G.
Gorkh , M.B.
Gourinath, S.
Govind, M.M.
Govindarajan, S.
Gowda, K. V .A.
Gowda, N.M.N .
Goyal , P.S.
Grenzer, J.
Grunewald, G.L..
Guang , X.
Guillot, R.
Guoping, Z.
Gupta, A.
Gupta, S.
Gupta, S.P.S.
Gupta, S.S.
Gupta, V.K.
Gureyev, T.E.
Guthohrlein , E.
Halder, S.

A6-116
A2-9
A6-23
A6-13, A6-23 ,
A6-73
A6-93
A4-4 7 , A4-48
A6-34
A6-23
A6-58
A2-3
A6-4, A6-5 ,A6-49
A4-11 , A4-12,
A4-13, A4-14,
A4-15
A4-4
A6-62
A6-111
A4-42
A4-29, A6-80
A6-108
A6-24
A5-19
A4-58
A4-36
A4-47, A4-48
A6-31
A2-3
PL-2
A6-123
A9-7
A6-16
A6-27
A4-56
A4-56, A5-37,
AS-38
AS-37
AS-32
A2-9
A6-58
A6-50

Hall, A.K.
Hall, S.R.
Hailer, K.J.

Hamada, K.
Hambley, T.W.
Hanafusa, Y.
Hanamura, T .
Hanasaki, T.
Hangloo, V.
Hansen, N.K.
Hao, J.
Harada, J.
Hariprasad, N.
Harrowfield, J.M.
Hase, T.
Hashizume, D.
Hata, Y.
Hayaishi, 0.
He, C.
He, H.
Hegde, R.P.
Hendrix, J.
Hikam, M.
Hikima, T .
Hikita, T.
Hocking, R.K.
Homma, K.
Honal, M.
Hong, T.
Hong, X.
Hongo, C.
Hongzhen,H.
Honma, N.
Horikoshi, M.
Horiuchi, H.
Hossain, Md.T.
Hosur, M.V.
Howard, C.J.
Howard, J.A.K.

A4-10
A1 0-12A4-4, A4-8,
A4-9, A8-2,
A8-9
A 10-3, A 10-5
A10-9
A5-23
A6-103
A4-59
A5-35, A5-41
A9-7
A?-12
A4-31
A6-10
A4-10
A6-14, A6-101
A4-20, A4-40,
A9-2
A6-120
A6-96, A6-122.
A6-23
A6-97
A6-83
A2-7
A5-26, A5-28
A6-65
A3-17
A10-9
A6-99
A8-7
A6-16, A6-55
A6-116
A6-46
A6-16, A6-117
A2-10
A6-8
A?-6
A6-65
A6-10, A6-66
A3-6
A4-4, A9-9

Hsiao, C.-D.
Hsieh, C.-H.
Hsu, 1.-J.
Hu, X.
Huang, Y.S.
Hui, Z.
Hung, C.Y.
Hung, L.T.
Hunter, K.A.
Hussain, A.
lchimura, S.
Ida, K.
ldakieva, K.
Igarashi, R.
lmura, H.
Inoue, T.
lrikura, D.
Ishida, K.
lshigami, H.
lshij ima, J.
lshitobi, S.
lsikawa, T.
lsobe, M.
lsshiki , M.
Ito, S.
Iwasaki, F.
lzui , K.
Jabeen, T.
Jain, A.
Jain, A.G.
Jain, D.
Jameson, G.B.
Jang, Y.-L.
Janin, J.
Jans, D.A.

A6-20
A9-1
A9-1
A5-9, A5-18
A1-5, A1 -6,
A1-7
A5-12
A1-6
A5-40
A10-4
A5-21
A6-47
A6-48
A6-58
A10-8
A2-10
A6-96, A6-1 05,
A6-119, A6-122
A6-96, A6-122
A3-9, A5-14,
A5-15, A5-43
A3-17
A6-98
A6-45
A5-15
A3-19
A2-10
A5-36
A4-20, A4-40,
A9-2
A6-119
A6-100A5-5, A5-22,
A10-1
A5-2
A6-15, A6-17,
A6-62
A6-6, A6-19,
A6-25
A4-69
A6-77
A6-11

Jasti, J.
Jayalakshmi, K.
Jeong, J.H.
Jeyabharathi, A.
Jeyaprakash, A.A.
Jeyaraman, R.
Jiang, F.
Jie, L.
Jin, J.
Jin, L.
Jinyuan, L.
Joachimiak. A.
Johnson, A.W.S .
Josh i, J.N.
Joshi, J.V.
Jotani, M.M.
Jou, Y.R .
Kai, Y.
Kakimoto, K.
Kaliannan , P.
Kamiya, N.
Kanda, H.
Kandasamy, M.
Kandaswamy, M.
Kanehisa, N.
Kaneko, S.
Kannan , K.K.
Kannan , N.
Karan, S.
Karandae, A.A.
Karino, N.
Kasinath , V.
Katayama, C.
Katoh , H.
Katsaras, J.
Katsuki, Y.
Kaur, H.
Kaur, K.J.
Kaur, P.

Kawano, M.

A6-112 , A6-113
A4-4 7, A4-48
A6-69
A4-1
A6-39
A4-2, A4-50
A6-21, A6-54,
A6-97
A10-6
A6-73
A6-13
A6-117
A6-97
A9-12
A2-2
A6-31
A6-57, A6-106
A1-8
A4-46, A6-96,
A6-119, A6-122
A5-36
A10-7
A6-98
A10-3
A4-30
A4-54, A4-55
A4-46
A6-125
A6-10, A6-66
A6-43
A5-38
A6-86
A6-1
A4-29
A2-10
A5-15
A6-109
A3-19
A8-6
A6-17, A6-62
A6-61 , A6-84,
A6-94, ft:6-112,
A6-113
A4-60

Kawasaki , K.
Kawata, Y.
Kengaku , Y.
Kennedy, B.
Kennedy, B.J.
Kenoth , R.
Khan, J.A.
Kiatphichitpong , A.
Kim, K.K.
Kimoto, K.
Kimura, H ~Kinugasa, S.
Kirianov, A.
Kiyanagi , R.
Klooster, W.T.
Knight, K.S.
Kobayashi, H.
Kobayashi , Y.
Kobe, B.
Koike, K.
Kokila, M.K.
Kokubun , J.
Kamiyama, S.
Kondo, H.
Konoike, Y.
Kosada, T.
Kotha,' S.
Kotru, P.N.

Krishnaiah, M.
Krishnakumar, R.V.
Krishnaswamy , D.
Krishnaswamy , S.
Kuberkar, D.G.
Kubota, T.
Kulkarni , G.U .
Kulkarni, M.V.
Kulkarni , R.G.
Kulkarni , U.D.

A6-28
A6-120
A10-8
A5-11
A3-4
A6-62
A6-32
A4-4
A6-69
A3-20
A2-12
A6-122, A6-96
A5-16
A2-12
A2-11
A3-6
A6-125
A5-16
A6-11
A5-42
A4-36, AB-3
A3-9, A5-14,
A5-43
A2-12
A6-28, A6-121
A9-10
A10-8
A6-50
A5-8, A5-30,
A5-31, A5-33,
A5-35, A5-41
A4-44
A6-38, A6-56
A4-65
A6-68, A6-79 ,
A6-86
A5-10
A6-99
A9-3
A4-36, A8-3
A5-10
A8-8

Kulkarni, V.M.
Kumagai, I.
Kumar, A.
Kumar, G.S.
Kumar, M.
Kumar, N.J.
Kumar, P.
Kumar, P.H.
Kumar, P.S.
Kumar, V .
Kumaran, D.
Kumasaka, T .
Kuno, A.
Kuo, C.C.
Kuppayee, M.
Kuramitsu, S.
Kurisu , G.
Kurniawan , B.
Kuroiwa, Y.
Kusaka, K.
Kusakabe , I
Kusunoki , M . .
Kuzuhara, T.
Laavanya, P.
Lai , L.-M .
Lai, S.C.
Lal, B.
Lalitha, K.
Lam, C.-K.
Larsen, S.
Le, Y.
Lee, C.K.Y .
Lee, G.-H.
Lee, Y.R.
Lei, S.
Leusen, F.

A6-10
A6-121
A5-32
A4-30
A6-66
A4-44
A6-24, A6-32,
A6-111
A6-27
A6-93
A6-114
A6-59
A6-48, A6-96,
A6-122, A 10-3,
A6-125
A1-8
A4-33, A4-54, .
A4-53
A6-98
A6-14 , A6-22,
A6-1 01 , A 10-8
A3-5
A9-6
A2-10
A6-125
A6-14, A6-22,
A6-1 01, A 10-8
A6-8
A4-50
A4-24
A1-6
A 5-8
A6-89
A4-61
A9-11
A6-97
A1-2
A4-69, A9-1
A1-5, A1-6 ,A1-7, A1-8
A6-55
A7-4

Li, D.
Li, H.
Li, H.-M.
Li, J.
Li, T .
Li, X.
Li, X.-Y.
Li, Z.H.
Liao, C.-Z.
Liaw, W.-F.
Lii, K.-H .
Lin, G.G.
Lin, G.Y.
Lin , H.-M.
Lin, W .
Lin , Y .-C.
Liu , J.
Liu, L.-K.
Liu , Y.

Liu, Y.-H.
Lo, S.M.-F.
Lokanath, N.K.
Lord, E.A.
Lu , C.-T.
Lu , T.-H.
Luca, V.
Luh, L.-8.
LukitoMa, s.-K.
Macintyre, G.J.
Madariaga, G.
Madsen, A.O.
Maeda, T.
Maesaki, S.
Mahajan, S.K.
Maiya, B.G .
Maji, T.Kr.
Mak, T.C.W.
Makde, R.D .

A6-54
A6-116
A6-20
A6-13
A6-53
A6-97
A4-23
A5-12
A4-28
A9-1
A4-38, A5-17
A1-8
A1-5, A1 "7
A5-17
A6-21, A6-54
A9-13
A6-97
A4-39
A5-18 , A6-13 ,A6-54, A6-55,
A6-97
A9-13
A4-23 , A4-24,
A9-9
A6-69
A8-1
A6-104A4-22, A4-62
A3-6
A4-39
A5-26
A4-19
A9-9
AS-5
A9-1 '1
A6-45
A2-12
A6-114
A6-62
A4-22, A4-62
A4-61
A6-114

Makker, J.
Malathi, R.
Malik, S.K.
Mallick, B.
Mallinson, P.R.
Mande, S.C .
Manikandan, K.
Manikandan , S.
Manonmani, J.
Marikani, A.
Marje, C.E.
Mark, B.
Martin, J.L.
Mason, S.A.
Masuda, I.
Masuda, J.
Matsuda, A.
Matsui, Y.
Matsumoto, H.
Matsumura, H.
Matumoto, T.
Maulik, P.R.
Mavani, K.
Mayo, S.C.
McCarthy, A.A.
Mcleish, M.J.
Mehta, P.
Miao, F.-M.
Miki, N.
Miki, R.
Miller, J.
Miller, P.R.
Ming, S.
Mingtao, Z.
Mishra, S.K.
Mishra, V.
Mitra, S.
Mittal, R.
Miyake, H.

A6-111
A4-29, A6-80
A5-10
A3-3
A9-8
A6-9
A6-37
A4-1
A4-54, A4-55
A7-1
A4-52
A6-16, A6-116
PL-2
A9-9
A5-36
A6-74
A6-1 , A6-65
A3-20
A4-20
A6-122, A6-96,
A6-119
A5-15
A4-6
A5-10
A2-9
A6-19
PL-2
A6-79
A4-19, A4-27,
A4-41 , A4-67
A4-20
A4-40
A6-2
A2-9
A4-41
A10-6
A3-1 5, A5-1 ,
A5-11
A6-3
A2-8
A3-1, A3-14
A6-22

Miyano,M.
Miyata, M.
Mizuki , J.
Mizuno, H.
Mizuno, H.
Mizushima, T.
Modh, R.D.
Mohan, S.
Mohana, K.N.
Mandai, T.K.
Mori, S.
Mori, T.
Morimoto, Y.
Morita, T.
Moss, D.S.
Mostafa, G.
Mukherjee, A.K.
Mukherjee, M.
Mukherji, S.
Mukhopadhayay, B.P.
Mukhopadhyay, A.
Mukhopadhyay, M.
Mukhopadhyay , R.
Muniyappa, K.
Munshi, P.
Murakami, Y.
Muraoka, J.
Murthy, G.S.
Murthy, M.R.N.

Murthy, M.S.
Murthy, V.N.N.
Murugavel , R.
Murugesan, S.
Muthiah, P.T.
Muthukrishnan, C.
Muthukumar, M.
Nagai, T.
Nagaraju, J.

A6-96, A6-122,
A10-3
A5-27
A2-6
A6-125
A6-29
A6-63
A6-108
A4-35
A4-32
A3-18
A3:2o
A7-6
A6-63, A6-74,
A6-103
A6-29
A6-2
A4-22, A4-62
A4-57
A2-3, A6-49
A6-111
A6-4
A 5-6
A2-3
A2-8
A6-71
A9-8
A3-19 , A3-21
A3-19
A6-68, A6-86
A6-36, A6-60,
A6-90, A6-91,
A6-92
A4-35
A8-3
A4-51
A6-75
A6-75 , A6-76
A3-7
A4-50
A3-20
A6-15

Nagendrappa, G.
Nair, D.T.
Naito, S.
Nakabayashi, M.
Nakai , T.
Nakamura, H .
Nakamura, N .
Nakamura, S.
Nakamura, Y.
Nakano, K.
Nakao, H.
Nakao, Y.
Nakashima, P.N.H.
Nakasuji, Y.
Nakayama, T.
Nalini, G.
Nallini, A.
Nandhini, M.S.
Nangia, A.
Narasimhamurthy, T.
NarendraMallya, M.
Natarajan, S.
Natesh, R.
Naylor, C.E.
Neumann, M.
Newbigin , E.
Ng , S.W.
Nice, E.C.
Ninomiya, E.
Ninomiya, Y.
Nirmala, K.A.
Nishibori , E.
Nishimiya, Y.
Nishimura, K.
Nishimura, S.
Nishino , N.
Nishiyama, D.
Nitta, Y.
Noda, J.
Noda, Y.
Nofrijon

A4-12, A4-13
A6-15
A6-1
A6-103
A6-98
A10-8
A4-34 , A4-59
A2-10
A2-10 , A6-44
A5-27
A3-19
A4-46
A9-12
A9-2
A2-5, A5-42
A5-13
A4-2
A6-38 , A6-56
A4-7
A4-14 , A4-15
A4-13
A6-38 , A6-56,
A1 0-10
A6-37
A6-2
A7-4
A6-48
A4-68
A6-11
A3-19
A5-14 , A5-43
A4-35 , A6-41
PL-3, A9-6
A6-121
A6-44 , A6-1 04
A6-22
A6-46
A6-14
A6-22
A6-99
A2-1 2
A5-28

Noguchi, K.
Noman, A.
Noren, L.
Norioka, S.
Nozawa, K.
Nurizzo, D.
Ochi , A.
Ogawa, K.
Ogawa, Y.
Ohara, H.
Ohashi , Y.

Ohgiya, S.
Ohsato, H.
Ohshima, K.
Ohsumi, K.
Ohwada, K.
Oike, S.
Okano, Y.
Okawa, T .
Okuda, T.
Okuyama, K.
Onuki, Y.
Othman, A.H .
Otsuka, C.
Ozeki, T.
Padiyan , D.P.
Padmanabhan, B.
Paganin, D.
Pal , A.K.
Palani, K.
Panchanatheswaran, K.
Pandey, D.
Pandey, S.
Pandi, A.S .
Pandita, S.
Panneerselvam , P.
Park, Y.J.

A5-23 , A6-46,
A6-47
A4-52
AB-5
A6-48
A10-5
A6-18
A2-4
A5-23, A4-31
A4-34
A9-10
A2-4, A2-10,
A4-45, A4-60,
A4-71
A6-28
A5-16, A5-36
A5-24
A3-10
A3-19
A2-10
A6-96, A6-122
A5-16
A5-36, A6-29
A5-23, A6-46,
A6-47, A7-9
A9-4
A4-68
A6-22
A2-10
A3-7, A7-1
A6-8
A2-9
A6-5
A4-32
A4-50
A3-1 5, A 5-1 ,A5-3, A5-11
A6-82
A4-3
A5-35
A6-75
A4-70

Parry, D.J .
Parthasarathi, V.

A2-~

Porob, D.G.
Prabakaran, P.
Prabhune, A.
Prabuswamy, B.
Prasad , R.
Prasanna, M.D.
Pratap, J.V.

A4-21 , A6-51, ·A6-52,
A1-1, A6-36 ,A6-90, A6-91 ,
A6-92
A6-58
A6-108
A6-1 08
A3-3
A6-57, A6-1 06,
A6-108
A2-2
A6-50, A6-89
A4-63
A4-69
A6-58
A6-18
A4-9
A5-25, A7-8
A2-3
A6-10
A6-115
A2-9
A6-39
A4-1, A4-2,
A4-32, A4-33,
A4-53, A4-54 ,A4-55, A6-59,
A6-67 A6-81
A7-2
A6-75
A6-12
A4-32
A6-79
A9-8
A6-30

Premkumar, T .
Pundle, A.
Puranik, V.G.
Puttaraja

A4-58
A6-12
A4-64, A4-65
A4-36, A8-3

Parthasarathy, S.

Parvanova, K.
Patel , B.D .
Patel, P.O .
Patel , T.
Patel , U.H.
Patra, A.K.
Pattabhi , V.
Pedireddi , V.R.
Peng, S.-M.
Perbandt, M.
Perlin , M.H.
Phothikanit, A.
Phuc, P.V.
Pietsch, U.
Pillai , B.
Pletnev, V.
Pogany, A.
Poi, M.-J.
Ponnuswamy, M.N.

I

Qiang , B.
Radhakrishna, V.
Rae, A.D.
Raghunathan , V.A.
RaginiRagunathan , R.
Rahman , M.M.
Raj, S.B .
Raj, S.S.S.
Rajagopal , K.
Rajakannan, V.
Rajan , R.
Rajan , S.S .
Rajanna, K.
Rajashankar, K.R .
Rajnikant
Raju , C.R.
Ram , V.J .
Ramachandraiah , G.
Ramagopal, U.A.
Ramakumar, S.
Ramamurthi , K.
Raman, S.S.S.
Ramanadham, M.
Ramasamy, P.
Ramaswamy, V.
Rana, D.S.
Ranford, J.D.
Ranganathan, A.T.
Rani, P.G.
Ranjan , R.
Rao, A.S.
Rao, M.N.
Rao, S.N.
Rao, Z .

A6-73
A2-1
A1-2, A8-2,
A8-9
A6-109
A5-11
A4-1
A4-52
A6-75
A1 -3
A6-38
A4-3, A6-39
A6-79
A4-29 , A6-80,
A6-93, A 10-11
A2-1 , A3-18
A6-42
A5-32
A4-32
A4-6
A6-26
A6-85
A6-37 A6-85
A4-21
A7-7
A3-16
A5-20
A?-5, A?-11 ,
A5-10
A4-25
A9-3
A6-30
A3-15, A5-3,
A5-11
A6-114A3-12
A4-3, A5-19
A6-13, A6-16,
A6-21 , A6-23,
A6-53, A6-54,
A6-73, A6-97,
A6-116, A6-117,
A6-118 , A6-123,
A6-124I

RashmiRath, N.P.
Ravichandran, S.
Rayaprol , S.
RayChaudhuri, N.
Ren , J.
Robert, J.J.
Rodgers , A.J.W.
Rong , G.
Row, T.N .G.
Rudland, P.
RudreshRukmini, M.R.
ROscher, C.H.
RuslanSada, K.
Sahal, D.
Sahni , N.
Sain, S.
Sakai , H.
Sakai , T.
Sakakibara, H.
Sakata, M.
Sakaue, T.
Sakiyama, F.
Saldanha, A.
Salunke, D.M.
Sampath , N.
Sangappa
Santosh , T.
Sanyal , M.K.
Saraboji , K.
Saraswathi , N.T.
Saravanakumar, D.
Saravanan , S .
Sasaki, S.
Sato, M.
Sato, S.
Sawa, H.
Sawai , H.

A?-10.
A4-58
A6-33
A5-10
A4-22
A6-54
A6-75
A6-64
A6-116
A4-4 , AS-13,
A?-2 , A9-8
A6-123
A6-85
A6-86
A5-21
A5-7
A5-27
A6-85
AS-35 , A5-41
A4-62
A6-120
A6-104
A6-101PL-3, A9-6
A6-1
A6-48
A6-105
A6-15 , A6-17,
A6-62
A6-67
A7-9
A6-89
A2-3
A4-33
A6-70
A4-30
A5-19
A9-10
A6-48
A3-17
A3-19
A5-14 , A5-43

Schenk, H.
Scudder, M.L.
Sekar, K.
Sembiring , T.
Sen, A.
Sen , A.
Sen , O.K.
Sengottuvelan , N.
Sengupta, K.
Sengupta, R.
Seshadri, P.R.
Seshadri , T.P.
Sethuraman, V.
Sethusankar, K.
Shah , A.
Shah , H.C.
Shaikh , A.M.
Shamala, N.
Shao, Y.
Shaofan , L.
Sharma, A.K.
Sharma, R.S.
Sharma, S.
Sharon , A.
Shashidhar, M.S.
Shashidharaprasad, J.
Shek, F.L.-Y.
Sheng , Y.
Sherawat, M.
Sheu , C.-F.
Sheu , H.-S.
Shewry, S.C.
Shi, N.
Shibata, N.
Shigeoka, S.
Shigesato, M.
Shingaya, Y.
Shingte, R.D.
Shionyu, C.
Shirai , T.

K1-1
A4-52
A 1-3, A6-30 ,
A6-39
A5-24
A3-14
A3-1
A3-8
A4-30
A6-109
A6-78
A4-3
A6-107
A6-75
A5-19
A6-51 , A6-52
A6-57 , A6-106
A2-1 , A2-2
A6-83, A6-87
A6-13, A6-97
A10-6
A6-72
A6-3
A6-24, A6-84 ,A6-100
A4-6
A4-42
A4-48
A4-24, A9-9
A6-16
A6-61
A9-1
A9-13
A6-18
A6-73
A6-74 , A6-103
A6-44
A5-27
A2-5
A4-64
A10-2
A 10-2, A6-99

A 3 : Crystallogr~phy in ph ys ic s
an d ea rt h sc ie nc es

Shiro, M.
Shishido, T.
Shivaprakash, N.C.
Shng, N.
Shui, X.
Shuping , Z.
Sikka, S.K.
Simpson, J.
Singh, A.K.
Singh, G.
Singh, H.
Singh, N.
Singh , R.K.
Singh, T.
Singh, T.P.

Singh, U.P.
Skelton , B.W.
Smith, A.D.
Smith, A.G.
Smith, C.A.
Smith ,P.S.
Soegijono, B.
Soejati , S.
Solomon, K.A.
Somashekar, R.
Somphon, W.
Son , L.H .
Sony, S.M.M.
Spadaccini , N.
Sreekanth , R.
Sridhar, M.A.
Srinivasan , A.
Srinivasan, K.
Srivastava, A.

A3-17
A?-6, AS-24
A8-3, A3-18
A6-23
A6-76
A6-16
PL-1
A10-4
A3-2, A5-1
A6-24, A6-84
A4-49
A6-72
A6-84, A6-1 00
A4-49
A6-3, A6-24,
A6-32, A6-61,
A6-68, A6-72 ,A6-84, A6-94,
A6-1 00, A6-111,
A6-112, A6-113
A6-107
A4-10
A6-34
A6-105
A6-18
A4-4
A5-7 , A5-26,
A5-28
A5-7
A4-29
A6-47, A?-9
A8-2 , A8-9
A?-8
A4-53, A4-54,
A4-55
A10-12
A1 0-11
A4-48
A6-32, A6-113
A5-20
A5-29

Srivastava, O.N .
Srivastava, P.
Stanley, N.
Stetsko, Y.P.
Stevenson, A.W.
Stoeva, S.
Streltsov, V.A.
Subramanya, H.S.
Sugadev, R.
Sugawara, H.
Sugawara, T.
Suguna, K.
Sujatha, V.
Sun, F.
Sun, Y.H .
Sun, Y.-J.
Sunami , T.
Sundarabaalaji , N.
Sung, H.H.-Y.
Suresh, C.G.
Suresh, E.
Sureshan , K.M.
Surolia, A.
Suzuki, M.
Swaminathan, G.J.
Swaminathan , S.
Swamy, M.J.
Tada, T.
Tagawa, T.
Takahashi , M.
Takahashi, T .
Takashima, N.
Takata, M.
Takayama, T.
Takenaka, A.
Takesue, N.
Tamakawa, K.
Tanaka, H.
Tanaka, K.

AS-4, AS-29,
A?-7
A4-6
A6-76, A6-75
A1-5, A1-6,
A1-7, A1-8,
A2-9
A6-58
A9-12, A6-110
A6-27
A6-81
A6-1 01
A4-60
A6-40
A6-79
A6-97
A5-12
A6-20
A6-1
A6-68
A4-23
A6-12
A4-17
A4-42
A6-26, A6-30,
A6-40
A6-28
A6-15
A6-59
A6-62
A6-44, A6-1 04
A5-15
A5-24
A4-59
A4-40
PL-3 , A9-6
A4-60
A6-1, A6-65
A1-4, A3-19
A9-2
A2-5, A9-6
A6-63, A9-4

Tanaka, M.
Tanaka, Y.
Tandon, R.P.
Taneja, B.
Tang , H.
Tang, K.
Tanimori, T.
Tashiro, K.
Teh , T.
Teng, B.
Teshima, K.
Thaker, C.M.
Thakurta, P.G .
Thampi , R.S.
Thirumuruhan, A.A.
ThiY,agarajq.n, S.
Tickoo; R.
Tiekink, E.R.T.
Titball , R.W.
Tiwari , R.K.
Tomisugi , Y.
Tong , H.
Toraya, H.
Toraya, T.
Tri , N.V.
Trigunayat, G.C.
Tsai , M.-D.
Tsuda, K.
Tsuda, S.
Tsukihara, T.
Tsumoto, K.
Tsunoda, M.
Tsunoda, S.P.
Tuong, L.T.C .
Turkenburg, J .
Tyagi, A.K.
Uchida, T.
Ueda, Y.
Uekusa, H.

A3-11, A7-6,
A9-5
A6-46
A5-33
A6-9
A6-13 , A6-97,
A6-123
A6-73
A2-4
A5-27
A6-11
A5-9
A6-14
A5-10
A6-78
A5-10
A4-55
A6-93
A5-33
A4-18
A6-2
A6-82
A6-63
A6-23
A7-3
A6-74
A8-4
A5-2
A6-39
A3-11 , A9-5
A6-28
A6-63
A6-121
A6-1, A6-65
A6-64
A5-25 , A7-8
A6-12
A3-14
A6-101
A3-19
A2-4, A2-1 0,
A4-45 , A4-60

Ueno, Y.
Umadevi, B.
Unno, M.
Uno, K.
Urade, Y.
Urs, U.K.
Usha, R.
Varma, A.K.
Varshney, U ~Vasu
Vasuki, G.
Velavan , S.
Velmurugan, D.
Veluraja, K.
Venkatraj , K.
Venugopalan , P.
Vijayalakshmi , L.
Vijayan, K.
Vijayan , M.

Vijayaraghavan , R.
Vishveshwara, S.
Viswamitra, M.A.
Vittal, J.J .
Vivian , J.P.
Voelter, W.
Vong , V.
Vora, V.
Wada, K.
Wadgaonkar, P.P.
Walia, P.
Walwalkar, M.G.
Wang , G.
Wang , J.
Wang , J.-L.
Wang , L.

A6-1 , A6-65,
A6-119
A6-76
A6-63
A4-34, A4-59
A6-96, A6-122
A4-4
A6-79
A6-3
A6-27
A4-35 , A6-41
A4-21
A4-3
A1-3, A4-3,
A5-19 , A6-39
A1 0-13
A4-2
A4-4 7, A4-49
A6-51 , A6-52
A5-5, A5-22 ,A10-1
A6-7, A6-26 ,A6-30, A6-40,
A6-70, A6-71 ,A6-88
A6-111
A6-43
A6-37
A4-16 , A4-25 ,
A4-26
A6-35
A6-58
A5-40
A6-51
A6-44
A4-64
A4-49
A4-43
A6-123
A5-9 , A5-12 ,A5-18
A4-19, A4-27 ,
A4-41
A6-55

Wang, T.
Wang , X.
Wang , Y.
Wang , Z.
Watanabe, A.
Watanabe, M.
Weihong , J.
Welberry, T.R .
White, A.H .
Whittaker, J.W.
Whittaker, M.M .
Wilce, J.A.
Wilce, M.
Wilce, M.C.J.
Wilke, S.
Wilkins, S.W.
Williams, I.D.
Willis, A.C .
Withers, R.L.
Wong, W .-T .
Wu, C. -A.
Wu ,D.
Wu,G .
Xiang, M.
Xie, Q.
Xie, Y.
Xin, Z .
Xu, M.-a.
Xu , Y .
Xuehui, C.
Yadav, S.
Yadava, V.S .
Yamamoto, M.
Yamane, H.
Yamane, T .
Yamashita, E.
Yang , C.-T.
Yang, W .
Yang, Y.

A6-102
A4-25, A6-123
A6-97 , A9-1 ,A9-13,
A6-23, A6-118 ,A6-123
A5-14, A5-43
A2-12
AS-16
AB-7
A4-10
A6-6 , A6-25
A6-6 , A6-25
A6-35
A6-110
A6-35 , AS-64
A7-4
A2-9
A4-23 , A4-24,
AB-2, A9-9
A1-2
AB-5
A4-66
A6-69
A5-12
A6-46
A6-16
A6-54
A4-46
A4-41
AS-118
A6-23 , A6-123
A6-55
A6-3
A6-114
A6-48 , A6-96,
A6-122, A10-3
A4-46
A1-3 , A6-99,
A10-2
A6-48
A4-16
A6-53
A4-27

Yao, X.
Yasuda, N.
Yasui, M.
Yasuoka, N.
Yathirajan, H.S.
Yi, D.
Yi, L.
Yiwei, L.
Yogavel , M.
Yokoyama, S.
Yoshida, K.
Yoshida, M.
Yoshimura, K.
Yoshinaga, T.
Yoswathananont, N.
You, H.
Yu, M.
Yu,W.
Yuan, H.
Yuan , J.
Yuanyuan , Q.
Yuhan,C.
Zhai, Z.H.
Zhang, B.
Zhang , H.
Zhang , R.
Zhao, N.
Zhao, Q.
Zhao, X.-L.L.R .
Zhen, Y.
Zhou, W.-H.

A7-12
A2-1 0, A4-45
A4-20 , A4-40,
A9-2
A6-63 , A6-74,
A6-103
A4-32
A6-16, AS-117
A6-117
A6-16
A6-39
A5-23
A5-42
A6-64
A6-44
A6-119
A5-27
A1-4
A4-27, A4-41
A5-9, A6-117
A1-6
A6-73
A10-6
A6-55
A6-53
A6-54
A6-54 , A6-123
A6-97
A6-97
A6-54
A4-67
A6-13
A4-19

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A- ~An advanced
anaiVUcaltool
to deal with a broad,in-dePth analvsisrHigh-resolution parallel beam o tics

JA DE 5.0
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Riga ku Inter natio nal Corp orat ion
Sendagaya, Shibuya-kv. Tokyo 151-005 1, Japan

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Photl(y.B1-3-3479-0018 Fax:81 ~3..s479-6112 o-ma :nnttyo@riglilku.c o.jp

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Fully solid-state technology•

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This new fully solid-state detector is based on the direct conversion of the absorbed
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249, Sharada Colony
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