bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytochromec‐549 ‐ an endogenous cofactor of cyclic photophosphorylation in the cyanobacteriumAnacystis nidulans?
Authors: Kienzl Peter F. , Peschek Günter A.
Published: July 2002

The cyanobacteriumAnacystis nidulanssynthesizes fairly large amounts of low potential cytochromec‐549 (E′o= −260 mV) during late logarithmic and stationary growth phases. We show here that isolated cytochromec‐549 catalyzed high rates of cyclic photophosphorylation by membrane preparations ofA. nidulanswhen added in about 50% reduced state; fully oxidized or reduced cytochromec‐549 was far less efficient. A similarly decisive role of proper redox poising was documented with ferredoxin as the cofactor of cyclic photophosphorylation. Inhibitor studies indicated that plastoquinone and cytochromefare involved in cyclic electron flow catalyzed by cytochromec‐549 and ferredoxin.
Characterization of a glyphosate‐insensitive 5‐enolpyruvylshikimic acid‐3‐phosphate synthase
Authors: Sost Dietrich , Schulz Arno , Amrhein Nikolaus
Published: July 2002

A glyphosate (N‐[phosphonomethyl]glycine)‐insensitive 5‐enolpyruvylshikimic acid‐3‐phosphate (EPSP) synthase has been purified from a strain of Klebsiella pneumoniae which is resistant to this herbicide [(1984) Arch. Microbiol. 137, 121‐123] and its properties compared with those of the glyphosate‐sensitive EPSP synthase of the parent strain. The apparent K
m values of the insensitive enzyme for phosphoenolpyruvate (PEP) and shikimate 3‐phosphate (S‐3‐P) were increased 15.6‐ and 4.3‐fold, respectively, as compared to those of the sensitive enzyme, and significant differences were found for the optimal pH and temperature, as well as the isoelectric points of the two enzymes. While PEP protected both enzymes against inactivation by N‐ethylmaleimide, 3‐bromopyruvate, and phenylglyoxal, glyphosate protected only the sensitive enzyme.
Isolation of an endogenous clonidine‐displacing substance from rat brain
Authors: Atlas Daphne , Burstein Yigal
Published: July 2002

An endogenous substance which specifically displaces clonidine, yohimbine and rauwolscine from rat brain α2‐adrenergic receptors, has been isolated. The new compound, designed clonidine‐displacing‐substance (CDS), has been partially purified by ion exchange chromatography, zone electrophoresis and high performance liquid chromatography (HPLC). CDS binds specifically to α2‐adrenergic receptors by competing with either α2‐adrenergic agonists or α2‐antagonists, but has no effect on the specific binding of [3H]prazosin to α1‐adrenergic receptors in rat brain membranes. In the course of isolation, CDS was shown to be neither the endogenous neurotransmitter (−)norepinephrine (NE) nor the guanyl nucleotide GTP which lowers the specific binding of α2‐agonists to the α2‐adrenergic receptors.
Purification and complete amino acid sequence of canine pancreatic secretory trypsin inhibitor
Authors: Kikuchi Norihisa , Nagata Kiyoshi , Yoshida Nobuo , Tanaka Tatsuhiko , Yamamoto Masahiro , Saitoh Yohichi
Published: July 2002

Pancreatic secretory trypsin inhibitor (PSTI) was purified from canine pancreatic juice by HPLC. Canine PSTI inhibited bovine trypsin activity stoichiometrically and strongly with a dissociation constant of below 10−9 M. The amino acid sequence of canine PSTI was determined by conventional methods. It had one more amino acid residue at the amino‐terminus than other mammalian PSTIs, i.e. human, porcine, bovine and ovine.
Binding of benzo(a)pyrene to rat lung glutathione S‐transferases in vivo
Authors: Singh Shivendra V. , Srivastava Satish K. , Awasthi Yogesh C.
Published: July 2002

A highly selective in vivo binding of benzo(a)pyrene to rat lung glutathione S‐transferases is demonstrated. Benzo(a)pyrene or its metabolites are specifically bound to Ya' and Yc subunits of rat lung glutathione S‐transferases.
Topography of RNA in the ribosome: location of the 5 S RNA residues A39 and U40 on the central protuberance of the 50 S subunit
Authors: Evstafieva A.G. , Shatsky I.N. , Bogdanov A.A. , Vasiliev V.D.
Published: July 2002

The internal site of 5 S RNA comprising residues A39 and U40 has been localized on the E.coli 50 S ribosomal subunit by immune electron microscopy. It has been found to be located on the interface side of the central protuberance at the position distinctly apart but very close to the position of the 5 S RNA 3'‐end providing evidence for a quite compact folded conformation of the 5 S RNA in situ.
Monoclonal antibodies specific for the light‐harvesting chlorophylla/b‐protein complex (LHC)
Authors: Thaler Thomas , Jay Frances A.
Published: July 2002

Monoclonal antibodies have been raised against the light‐harvesting chlorophylla/b‐protein complex (LHC) of pea and characterised using the enzyme linked immunosorbent assay (with purified LHC or intact thylokoids) or immunoblotting using chloroplast proteins transferred from SDS‐PAGE gels. Several clones showed strong binding to the two major polypeptides of pea LHC, even after trypsin or proteinase K treatment. The two antibodies with the most efficient binding to pea LHC were shown to cross‐react with polypeptides from green algae and higher plants; indicating sequential similarities and the presence of several closely related polypeptides between phylogenetically distant species.
Footprinting of DNA secondary structure by high‐intensity (laser) ultraviolet irradiation
Authors: Budowsky E.I. , Kovalsky O.I. , Yakovlev D.Yu. , Simukova N.A. , Rubin L.B.
Published: July 2002

The action of high‐intensity ultraviolet pulse laser radiation on a 161 bp fragment of pBR 322 DNA (EcoRI‐Msp I fragment) was studied. At doses up to 5 × 1018 photons/cm2 the N‐glycosidic bond splitting is negligible. The action of hot piperidine on irradiated DNA leads to chain splitting at the residues, modified via biphotonic processes. The modification and, hence, splitting efficiences depend on the type of base (G>T>A>C) and on its position in the sequence. Preferentially modified bases in the opposite strands of double‐stranded DNA belong, mainly, to the same or adjacent base pairs. Residues in the Pribnow box are modified considerably less, than in the sequences, immediately upstream and downstream. This approach seems to be useful in footprinting of DNA secondary structure peculiarities and alterations, conjugated with the functional role and state of the respective fragment.
Adenosine transporters in chromaffin cells
Authors: Torres M. , Molina P. , Miras-Portugal M.T.
Published: July 2002

Chromaffin cells from bovine adrenal medulla are a useful model to approach adenosine transport and metabolism in neural cells. Dipyridamol has been shown to be an adenosine transport inhibitor with high affinity. To quantify the adenosine transporters a labelled dipyridamol analogue, [14C]dipyridamol acetate, was synthesized. This compound had a K
i = 5.3 ± 0.43 nM according to the Dixon method, and 4.58 ± 0.46 nM when the receptor number molarity was taken into account showing, like dipyridamol, a non‐competitive mechanism. The high‐affinity receptors present in chromaffin cells showed a K
d = 6.8 ± 0.8 nM and the receptor number was 630000 ± 40000 per cell.
The reduction‐oxidation status may influence the degradation of glyceraldehyde‐3‐phosphate dehydrogenase
Authors: Knecht Erwin , Roche Enrique
Published: July 2002

NADH and NADPH accelerate the ‘in vitro’ rate of proteolysis of glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) by elastase and other proteases, including lysosomal proteases. NAD+ and NADP+ have the opposite effect. Since there is a good correlation between proteolytic susceptibility of proteins and their ‘in vivo’ degradation rates, a possible role of the reduction‐oxidation status in controlling the intracellular degradation of GAPDH is advanced.
Coding sequences for chloroplast ribosomal protein S12 from the liverwort, Marchantia polymorpha, are separated far apart on the different DNA strands
Authors: Fukuzawa Hideya , Kohchi Takayuki , Shirai Hiromasa , Ohyama Kanji , Umesono Kazuhiko , Inokucri Hachiro , Ozeki Haruo
Published: July 2002

During the nucleotide sequencing of chloroplast DNA from the liverwort, M. polymorpha, we found that a coding sequence corresponding to the Esherichia coli ribosomal protein S12 gene (rps 12) is split into three exons. Strikingly, the first exon with the 5'‐intron boundary sequence was found on the opposite strand of the chloroplast DNA (120 kilobases long, circular molecules) approx. 60 kilobases away from the rest of the exons. The amino acid sequence deduced from the DNA sequence was highly homologous to the sequences of the S12 ribosomal protein of E. coli (70.2%), and Euglena gracilis chloroplasts (73.6%). Possible mechanisms for the expression of this split gene are discussed.
Identification of the active site of Citrobacter freundii β‐lactamase using dansyl‐penicillin
Authors: Yamaguchi Akihito , Adachi Hideki , Sawai Tetsuo
Published: July 2002

The active site sequence of a β‐lactamase encoded by chromosomal gene(s) in Citrobacter freundii GN346 was determined using dansyl‐penicillin as a fluorescent probe. The tryptic digest of the labelled enzyme gave a fluorescent peptide containing 22 amino acids. The sequence of this peptide was identical to the consensus sequence of class C β‐lactamases, Gly‐Ser‐X‐Ser‐Lys. The residue labelled was the serine adjacent to the glycine. The active site sequence corresponded to positions 46–67 of the entire sequence of the Citrobacter freundii β‐lactamase determined on the basis of the DNA sequence of the structural gene [(1986) Eur. J. Biochem. 156, 441–445]. The labelled serine corresponded to Ser‐64.
Translocation of protein kinase C in rat islets of Langerhans Effects of a phorbol ester, carbachol and glucose
Authors: Persaud Shanta J. , Jones Peter M. , Sugden David , Howell Simon L.
Published: July 2002

In unstimulated rat islets (2 mM glucose), most of the ion‐exchange purified protein kinase C (PKC) activity was associated with the cytosolic fraction. Both carbachol and phorbol myristate acetate caused a significant translocation of PKC activity from cytosolic to membrane fractions, but under the same conditions, glucose (20 mM) did not cause such a redistribution of PKC activity. PMA‐induced translocation of PKC to the membrane fraction was also observed in electrically permeabilised islets, in which recovery of the enzyme activity was enhanced by buffering the intracellular Ca2+ concentration to 50 nM and supplying the permeabilised islets with protease inhibitors.
Direct evidence that the kinase activity of protein kinase C is involved in transcriptional activation through a TPA‐responsive element
Authors: Hata Akiko , Akita Yoshiko , Konno Yasuhiko , Suzuki Koichi , Ohno Shigeo
Published: July 2002

In order to examine the involvement of protein kinase C (PKC) in the transcriptional activation of genes by TPA (12‐O‐tetradecanoyl phorbol 13‐acetate) we have constructed a series of PKC expression plasmids. Transient expression of an active fragment of PKC in rat fibroblasts resulted in the transcriptional activation of a TRE (TPA‐responsive element)‐CAT chimeric gene which contains various repetitions of collagenase TREs. These provide the first direct evidence that kinase activity of PKC is involved in TPA‐induced transcriptional activation through TRE.
Dendrotoxin and charybdotoxin increase the cytosolic concentration of free Ca2+ in cerebrocortical synaptosomes: An effect not shared by apamin
Authors: Tibbs Gareth R. , Nicholls David G. , Dolly J.Oliver
Published: July 2002

Nanomolar concentrations of charybdotoxin or dendrotoxin increase the cytoplasmic free Ca2+ concentration in isolated central nerve terminals. The effects of the two toxins, normally considered to be blockers of K+ channels controlled by voltage in a Ca2+ ‐sensitive or ‐insensitive manner, respectively, show only marginal additivity. Apamin, an inhibitor of low conductance Ca2+ ‐activated K+ channels, was without effect in either the absence or presence of dendrotoxin. The effect of charybdotoxin on polarized, isolated central nerve terminals seems to be mediated largely by a block of K+ channels sensitive to dendrotoxin. Apparently, these voltage‐operated K+ channels make a more significant contribution to maintaining the polarized potential of synaptosomes than do those activated by Ca2+.
Tightly bound pyrophosphate inEscherichia coliinorganic pyrophosphatase
Authors: Shestakov Alexander A. , Baykov Alexander A. , Avaeva Svetlana M.
Published: July 2002

Hexameric inorganic pyrophosphatase ofEscherichia colicontains about 1of ‘structural’ pyrophosphate, which survives gel nitration and prolonged incubation with Mg2+, does not exchange with medium phosphate and pyrophosphate but is removed with 0.8 M perchloric acid. The site of pyrophosphate binding seems to be another than the active site. An additional 0.9 mol of enzyme‐bound pyrophosphate is formed in the presence of phosphate and Mg2+but this pyrophosphate is in fast equilibrium with medium phosphate and appears to be bound to the active site.
Localization of an estrogen receptor binding site near the promoter of the uteroglobin gene
Authors: de Haro M.S.López , García C. , Nieto A.
Published: July 2002

By means of a DNA‐cellulose competitive binding assay, we have studied the interaction of the estrogen receptor with genomic fragments of the estrogen responsive rabbit uteroglobin gene. The fragments spanned from 3255 bp upstream to 1754 bp downstream of the initiation site. Only a fragment (−396/ + 8) showed strong affinity for the receptor. Within this fragment a unique palindromic sequence (GGTCAccaTGCCC) was found which is very similar to the canonical consensus sequence for the estrogen receptor. A synthetic oligonucleotide of that structure specifically competed for the binding of the receptor to DNA‐cellulose.
Purification and site‐specific immobilization of genetically engineered glucose dehydrogenase on thiopropyl‐sepharose
Authors: Persson Mats , Bülow Leif , Mosbach Klaus
Published: July 2002

The gene encoding glucose dehydrogenase (EC 1.1.1.47) from Bacillus subtilis was inserted in a plasmid 1.0 kb downstream from a lac promoter, resulting in a 70‐fold higher production of the enzyme when expressed in Escherichia coli. A glucose dehydrogenase mutant containing a cysteine residue at position 44 could also be expressed at the same high level. This single cysteine residue was used as an ‘affinity tag’ to simplify the purification procedure as well as for site‐specific immobilization of glucose dehydrogenase on Thiopropyl‐Sepharose. This enzyme was purified to homogeneity with a final recovery of 65% and a specific activity of 240 . The oriented immobilization resulted in increased thermal stability.
Crystallization and preliminary X‐ray studies of annexin IV (endonexin), a calcium‐dependent phospholipid‐binding protein
Authors: Boustead Catherine M. , Walker John H. , Kennedy David , Waller David A.
Published: July 2002

Annexin IV (endonexin) has been purified from chicken liver and crystallized by the vapour diffusion method. Crystals which diffract to at least 2.2 Å have been obtained. They belong to space group R3 and have unit cell dimensions of a = b = 99.4 Å, c = 96.2 Å, α = 90°, β = 90°, γ = 120°. There is one molecule of 32 500 Da per asymmetric unit.
Resonance Raman study of cytochrome aa3 from Sulfolobus acidocaldarius
Authors: Hildebrandt Peter , Heibel George , Anemüller Stefan , Schäfer Günter
Published: July 2002

The single subunit terminal oxidase of Sulfolobus acidocaldarius, cytochrome aa
3, was studied by resonance Raman spectroscopy. Results on the fully oxidized, the fully reduced, and the reduced carbon monoxide complex are reported and compared with those of sucaryotic cytochrome oxidase. It is shown that in both redox states the hemex a and a
3 are in the six‐coordinated low‐spin and six‐coordinated high‐spin configuration, respectively. The resonance Raman spectra reveal far‐reaching similarities of this archaebacterial with mammalian or plant enzymes except for the reduced form of heme a. The formyl substituent of this heme appears above 1 640 cm−1, ruling out significant hydrogen bonding interactions which is in sharp contrast to beef heart cytochrome oxidase. In addition, frequency upshifts of the marker bands ν4 and ν2 are noted indicating differences in the electron density distribution within the molecular orbitals of the porphyrin.
A method to study the rapid phosphorylation‐related modulation of neutral trehalase activity by temperature shifts in yeast
Authors: De Virgilio Claudio , Bürckert Niels , Boller Thomas , Wiemken Andres
Published: July 2002

Heat shock enhanced the synthesis of neutral trehalase in growing cells of Saccharomyces cerevisiae, as detected by immunological methods. The activity of the enzyme was measured in extracts obtained by two methods: cells were either harvested by filtration and subsequent disruption with glass beads at 0–4°C or immediately frozen with liquid nitrogen in the presence of Triton X‐100, followed by thawing at 30°C. The first procedure yielded artificially high activities of neutral trehalase in heat‐shocked cells due to rapid (<1 min) activation during handling at 4°C before homogenization. Activity of the enzyme in these homogenates decreased 75–90% upon a treatment with alkaline phosphatase, indicating that activation was due to phosphorylation. The second procedure yielded low trehalase activities for heat‐shock treated cells, much higher activities for cells shifted back for some seconds to 27°C, and very low activities again for cells shifted from 27 to 40°C for a second time. Thus, permeabilization of cells following rapid freezing in Triton X‐100 is a method of choice to study post‐translational modulation of the neutral trehalase of S. cerevisiae by phosphorylation and dephosphorylation.
In vitro enzyme activation with calbindin‐D28k, the vitamin D‐dependent 28 kDa calcium binding protein
Authors: Reisner Peter D. , Christakos Sylvia , Vanaman Thomas C.
Published: July 2002

Purified porcine erythrocyte membrane Ca2+‐ATPase and 3′:5′‐cyclic nucleotide phosphodiesterase were stimulated in a dose‐dependent, saturable manner with the vitamin D‐dependent calcium binding protein from rat kidney, calbindin‐D28k (CaBP‐D28k). The concentration of CaBP‐D28k required for half‐maximal activation (K
0.5 act.) of the Ca2+‐ATPase was 28 nM compared to 2.2 nM for calmodulin (CaM), with maximal activation equivalent upon addition or either excess CaM or CaBP‐D28k, 3′:5′‐Cyclic nucleotide phosphodiesterase (PDE) also showed equivalent maximum saturable activation by calbindin (K
0.5 act. = 90 nM) or calmodulin (K
0.5 act. = 1.2 nM). CaBP‐D28k was shown to effectively compete with CaM‐Sepharose for PDE binding. Immunoprecipitation with CaBP‐D28k antiserum completely inhibited calbindin‐mediated activation of PDE but had no effect on calmodulin's ability to activate PDE. While the physiological significance of these results remains to be established, they do suggest that CaBP‐D28k can activate enzymes and may be a regulator of yet to be identified target enzymes in certain tissues.
Different flexibility of the upstream regulatory regions of two differently expressed pea rbcS genes studied by theoretical evaluation of DNA distortion energy and cyclization kinetics
Authors: Cacchione Stefano , De Santis Pasquale , Savino Maria
Published: July 2002

Different superstructural features of the upstream regulatory regions of the two pea genes rbcS‐3A and rbcS‐E9 have been derived using a theoretical method, developed in our laboratory a few years ago, which evaluates the DNA distortion energy from a matrix of the deviations of the 16 possible dinucleotides from the standard B conformation. The theoretical analysis, which predicts different flexibilities of the regulatory regions of the two genes, is in satisfactorily good agreement with experimental evaluations from gel electrophoretic mobility and cyclization kinetics, suggesting a possible model to explain the largely different transcription efficiencies of the two genes.
The membrane proteins encoded by yeast chromosome III genes
Authors: Goffeau A. , Nakai Kenta , Slominski Piotr , Risler Jean-Loup
Published: July 2002

Examples are given for the analysis of the 68 putative membrane proteins encoded among the 170 predicted genes identified by the systematic sequencing of yeast chromosome III [(1992) Nature 357, 38‐56].
Mitochondrial oxidative phosphorylation in saponin‐skinned human muscle fibers is stimulated by caffeine
Authors: Kunz Wolfram S. , Kuznetsov Andrey V. , Gellerich Frank N.
Published: July 2002

The addition of 15 mM caffeine to saponin‐skinned human muscle fibers from M. vastus lateralis caused in the presence of 2 mM ATP an approx. 2‐fold stimulation of respiration with glutamate + malate. This effect can be abolished by either the addition of the Ca2+ chelator EGTA, the inhibitor of Ca2+ transport Ruthenium red and the inhibitor of the myosin ATPase vanadate. The caffeine concentration dependency of respiration of fibers coincided with the caffeine‐caused stimulation of myosin ATPase activity. The activation of oxidative phosphorylation in saponin‐skinned human muscle fibers by caffeine can be explained by a stimulation of myosin ATPase caused by Ca2+ release from sarcoplasmic reticulum.
Monoclonal antibodies against metalloporphyrins. Specificity of interaction with structurally different metalloporphyrins
Authors: Savitsky Alexander P. , Demcheva Marina V. , Mantrova Ekaterina Yu. , Ponomarev Gely V.
Published: July 2002

Monoclonal antibodies against Pd‐coproporphyrin I have been obtained. The antibody specificity for free as well as for conjugated Pd‐coproporphyrin I is characterized. Affinity constants are estimated for 3 monoclonal antibodies effectively interacting with free Pd‐coproporphyrin I. A comparative study on the binding of monoclonal antibodies with analogues and derivatives of Pd‐coproporphyrin I has revealed that the antigen is mainly located inside the antibody paratope. The protein adjoins complementary to the metalloporphyrin in such a manner that antibodies obtained discern only isomer I, and to some degree, isomer III of coproporphyrin.
Stereochemistry of the hydrolysis of glycosidic linkage by endo‐β‐1,4‐xylanases ofTrichoderma reesei
Authors: Biely Peter , Kremnický Lubomír , Alföldi Juraj , Tenkanen Maija
Published: July 2002

Methyl β‐d‐xylotrioside was used as a non‐reducing substrate to investigate the stereochemistry of hydrolysis of, β‐1,4‐xylopyranosidic linkage by purified endo‐β‐1,4‐xylanases (EC 3.2.1.8) ofTrichoderma reesei, employing1H NMR spectroscopy. The fungus produces one acidic species (pI 4.8–5.5), designated as EXI, and one alkaline species (pI 8.5–9.0), designated as EXII. Both enzymes were found to cleave the xylotrioside predominantly to methyl β‐d‐xyloside and xylobiose. Monitoring of the intensity of the H‐1 signals of α‐ and β‐xylobiose during the time course of hydrolysis clearly showed that both enzymes liberate the β‐anomer of xylobiose, i.e. a product with anomeric configuration identical with that of the cleaved glycosidic linkage. This means that both EXI and EXII belong to the so‐called retaining glycanases that utilize the double displacement reaction mechanism of hydrolysis.
Human immunodeficiency virus type 1 (HIV‐1) recombinant reverse transcriptase
Authors: Sharma Satish K. , Fan Naisheng , Evans David B.
Published: July 2002

A recombinant p66 form of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) can be obtained [(1991) Biotechnol. Appl. Biochem. 14, 69‐81] from crude Escherichia coli extracts by immobilized metal affinity chromatography (IMAC). We have analyzed the p66 HIV‐1 RT, isolated in the presence of 0.3 M imidazole, by gel permeation HPLC on Superose 12. The results show that it contains two major distinct p66 forms (24.1 min and 28.3 min peaks) which are distinguishable from the purified homodimeric (p66/p66) HIV‐1 RT (22.2 min peak). Protein peak 1 (24.1 min) is converted to a 22.3 min peak upon storage for 20 h at 4°C. Under identical conditions, the isolated peak 2 (28.3 min) appeared as a conformationally heterogeneous mixture elaborated by peaks at 22.3 min and 25.9 min. The protein species thus obtained were active in the RNA‐dependent DNA polymerase and RNase H activity assays and produced heterodimeric HIV‐1 RT upon incubation with the HIV‐1 protease. When the IMAC‐purified, imidazole‐free homodimeric (p66/p66) form of the enzyme was incubated with 0.3 M imidazole for 16 h at 4°C, protein peaks at 28.3 min (peak A) and 30.5 min (peak B) were isolated by gel permeation HPLC. While both of these p66‐containing species were stable and displayed identical RNA‐dependent DNA polymerase activities, the protein in peak B was only 50% active in RNase H function compared with the protein from peak A. These imidazole‐mediated dissociation studies support the hypothesis of partial unfolding of one of the RNase H domains of the p66/p66 homodimer, suggesting that the p66 subunits are asymmetric in the native enzyme.
Localization of disulfide bridges and free sulfhydryl groups in human eosinophil granule major basic protein
Authors: Oxvig Claus , Gleich Gerald J. , Sottrup-Jensen Lars
Published: July 2002

Eosinophil granule major basic protein (117 residues) is known to contain free sulfhydryl groups. Here we have located in the amino acid sequence the half‐cystine residues present as cysteine, and identified those engaged in disulfide bridges. Of the 9 half‐cystine residues, 5 are unpaired cysteines (Cys2, Cys23, Cys42, Cys64, and Cys96), while 4 form disulfides (Cys20‐Cys115, and Cys92‐Cys107).
Developmental changes in purine nucleotide metabolism in cultured rat astroglia
Authors: Zoref‐Shani E. , Bromberg Y. , Lilling G. , Gozes I. , Brosh S. , Sidi Y. , Sperling O.
Published: July 2002

The present study was conducted in order to clarify the role of the glia in brain purine metabolism. This, in connection with the clarification of the etiology of the neurological manifestations associated with some of the inborn errors of purine metabolism in man. Purine nucleotide content, the capacity for de novo and salvage purine synthesis and the activity of several enzymes of purine nucleotide degradation, were assayed in primary cultures of rat astroglia in relation to culture age. The capacity of the intact cells to produce purine nucleotides de novo exhibited a marked decrease with the culture age, but the activity of hypoxanthine‐guanine phosphoribosyltransferase (HGPRT), catalyzing salvage nucleotide synthesis, increased. Aging was also associated with a marked increase in the activity of the degradation enzymes AMP deaminase, purine nucleoside phosphorylase (PNP) and guanine deaminase (guanase). The activity of adenosine deaminase and of AMP‐5′‐nucleotidase, increased markedly during the first 17 days in culture, but decreased thereafter.

The results indicate that purine nucleotide metabolism in the cultured astroglia is changing with aging to allow the cells to maintain their nucleotide pool by reutilization of preformed hypoxanthine, rather than by de‐novo production of new purines. Aging is also associated with increased capacity for operation of the adenine nucleotide cycle, contributing to the homeostasis of adenine nucleotides and to the energy charge of the cells. In principle, the age‐related alterations in purine metabolism in the astroglia resemble those occurring in the maturating neurons, except for the capacity to produce purines de novo, which exhibited inverse trends in the two tissues. However, in comparison to the neurons, the cultured astroglia possess the capacity for a more intensive metabolism of purine nucleotides.
Apaf‐1 localization is modulated indirectly by Bcl‐2 expression
Authors: Ruiz-Vela Antonio , Albar J.P , Martı́nez-A Carlos
Published: July 2002

Apoptotic protease activating factor‐1 (Apaf‐1) is an adaptor molecule essential for caspase‐9 activation. Subcellular analysis of Apaf‐1 in NIH‐3T3 fibroblasts and the immature murine B cell lymphoma WEHI‐231 indicates that Apaf‐1 is localized in the Golgi apparatus and cytoplasm. Bcl‐2 overexpression in WEHI‐231 cells disrupts Apaf‐1 localization in Golgi, causing a perinuclear Apaf‐1 redistribution. Bcl‐2 overexpression in NIH‐3T3 fibroblasts however does not cause similar Apaf‐1 redistribution, suggesting that cell type factors are involved in the redistribution process. The ability of Bcl‐2 to modify Apaf‐1 subcellular localization is not explained by direct interaction between Apaf‐1 and Bcl‐2. These data may help to clarify the anti‐apoptotic Bcl‐2 function.
Insertion of foreign random sequences of 120 amino acid residues into an active enzyme
Authors: Doi Nobuhide , Itaya Mitsuhiro , Yomo Tetsuya , Tokura Seiichi , Yanagawa Hiroshi
Published: July 2002

Random sequences of 120–130 amino acid residues were inserted into a surface loop region of Escherichia coli RNase HI. This library was screened and about 10% of the clones were found to retain RNase H activity. Subsequent random mutagenesis led to an increase in RNase H activity and solubility of the protein. The inserted regions were found not to contribute to the secondary structure of the mutant protein. The high frequency of insertion of flexible sequences and the increase in the protein's function by further mutagenesis simulate one of the events in protein evolution.
A major 170 kDa protein associated with bovine adrenal medulla microtubules: a member of the centrosomin family?
Authors: Severin Fedor F , Shanina Nina A , Shevchenko Andrej , Solovyanova Olga B , Koretsky Vasiliy V , Nadezhdina Elena S
Published: July 2002

Microtubules isolated from bovine adrenal medulla cells contain a major 170 kDa protein (p170). p170 is heat‐labile and is associated with microtubules in an ATP‐insensitive manner. This protein was purified to near homogeneity using FPLC. A preparation containing purified p170 caused bundling of microtubules. By microsequencing of p170, two polypeptides were identified which appeared to be identical to a recently sequenced p167 centrosomin‐related protein. Polyclonal affinity‐purified anti‐p170 antibody was found to immunostain microtubules and to recognize the 170 kDa polypeptide in culture cells. We suggest that p170 is a new member of a centrosomin family and is a new structural protein associated with microtubules in some cell types.
Differential effects of ceramides upon adenylyl cyclase subtypes
Authors: Bösel Angela , Pfeuffer Thomas
Published: July 2002

Ceramides are reported to stimulate different effector systems, among them atypical protein kinases C (PKCs). When HEK 293 cells, stably expressing adenylyl cyclase type II (AC II), were treated with various ceramide derivatives, adenylyl cyclase activity was enhanced 8–15‐fold. The stimulation by the most potent analog, C18/C24 ceramide, was comparable to that by the phorbolester TPA. The stimulatory effect of ceramide was not restricted to AC II, although the type I and type V enzymes were affected less dramatically. Unexpectedly, the dihydro derivatives of ceramides, generally serving as non‐activating controls, exhibited only slightly lower stimulation than ceramides, whereas short‐chain ceramides (e.g. C2) were without effect. The action of ceramides was at least partially inhibited by okadaic acid, suggesting involvement of a phosphatase. Furthermore, ceramides and TPA operated synergistically. While the PKC inhibitor staurosporine counteracted the action of phorbolesters, it significantly (2.5×) enhanced the effect of ceramides.
The yeast gene YJR025c encodes a 3‐hydroxyanthranilic acid dioxygenase and is involved in nicotinic acid biosynthesis
Authors: Kucharczyk Roza , Zagulski Marek , Rytka Joanna , Herbert Christopher J
Published: July 2002

We have deleted the yeast gene YJR025c and shown that this leads to an auxotrophy for nicotinic acid. The deduced protein sequence of the gene product is homologous to the human 3‐hydroxyanthranilic acid dioxygenase (EC 1.13.11.6) which is part of the kynurenine pathway for the degradation of tryptophan and the biosynthesis of nicotinic acid. In cell‐free extracts the 3‐hydroxyanthranilic acid dioxygenase activity is proportional to the copy number of the YJR025c gene. As YJR025c encodes the yeast 3‐hydroxyanthranilic acid dioxygenase, we have named this gene BNA1 for iosynthesis of icotinic cid.
Disruption of Escherichia coli transaldolase into catalytically active monomers: evidence against half‐of‐the‐sites mechanism
Authors: Schörken Ulrich , Jia Jia , Sahm Hermann , Sprenger Georg A. , Schneider Gunter
Published: July 2002

Disruption of the hydrogen bonding network at the interface of Escherichia coli transaldolase by substitution of R300 to a glutamic acid residue resulted in a monomeric enzyme at basic pH values, with almost no change in the kinetic parameters. The stability of the R300A and R300E mutants towards urea and thermal inactivation is similar to that of the wild‐type enzyme. X‐ray analysis showed that no structural changes occurred as a consequence of the side chain replacement. This indicates that the quaternary structure is not required for catalytic activity nor does it contribute significantly to the stability of the enzyme. The results are not consistent with a proposed half‐of‐the‐sites reaction mechanism.
An Arabidopsis 14‐3‐3 protein can act as a transcriptional activator in yeast
Authors: Wang Jing , Goodman Howard M , Zhang Hong
Published: July 2002

The 14‐3‐3 proteins are a group of highly conserved and widely distributed eukaryotic proteins with diverse functions. One 14‐3‐3 protein, AFT1 from Arabidopsis thaliana, was found to be able to activate transcription in yeast. When fused to the DNA‐binding domain of a bacterial protein LexA, AFT1 can activate transcription of reporter genes that contain LexA operator sequences in their promoters. Although the in vivo function of AFT1 is not completely known, its similarity to previously identified proteins found in transcription complexes of Arabidopsis and maize suggests that AFT1 and some other 14‐3‐3 proteins may activate gene expression in other systems as well.
Studies of a putative ice‐binding motif in winter flounder skin‐type anti‐freeze polypeptide
Authors: Lin Qingsong , Ewart K.Vanya , Yang Daniel S.C , Hew Choy L
Published: July 2002

Winter flounder contains two distinct anti‐freeze protein isoforms, which are the liver‐type extracellular anti‐freeze proteins and the skin‐type intracellular anti‐freeze protein. The skin‐type anti‐freeze proteins exhibit lower anti‐freeze activities than the liver‐type isoforms and this might be due to their lacking complete ice‐binding motifs. One of the skin‐type anti‐freeze proteins, skin‐type anti‐freeze protein‐3, does contain putative overlapping ice‐binding motifs with the sequences ‘‐K—DT‐’ and ‘‐DT–K‐’. Synthetic anti‐freezes containing 0–3 repeats of the ‘‐DT–K‐’ motif were tested for stability and activity. Loss of the single ‘‐DT–K‐’ of skin‐type anti‐freeze protein‐3 increases the anti‐freeze activity and increasing the number of motifs to two or three lowers the activity. The decrease in activity with an increasing frequency of the motif correlates with a decrease in the helical content of these peptides at 0°C.
Intracellular distribution of hepatic glucokinase and glucokinase regulatory protein during the fasted to refed transition in rats
Authors: Fernández-Novell Josep M. , Castel Susanna , Bellido David , Ferrer Juan C. , Vilaró Senen , Guinovart Joan J.
Published: July 2002

We have studied the intracellular distribution in vivo of glucokinase (GK) and glucokinase regulatory protein (GKRP) in livers of fasted and refed rats, using specific antibodies against both proteins and laser confocal fluorescence microscopy. GK was found predominantly in the nucleus of hepatocytes from starved rats. GK was translocated to the cytoplasm in livers of 1‐ and 2‐h refed animals, but returned to the nucleus after 4 h. GKRP concentrated in the hepatocyte nuclei and its distribution did not change upon refeeding. These results show that, in physiological conditions, GKRP is present predominantly in the nuclei of hepatocytes and that the translocation of hepatic GK from and to the nucleus is operative in vivo.
The first determination of pseudouridine residues in 23S ribosomal RNA from hyperthermophilic Archaea Sulfolobus acidocaldarius
Authors: Massenet Séverine , Ansmant Isabelle , Motorin Yuri , Branlant Christiane
Published: July 2002

We describe the first identification of pseudouridine (Ψ) residues in ribosomal RNA (23S rRNA) of an hyperthermophilic Archaea Sulfolobus acidocaldarius. In contrast to Eucarya rRNA, only six Ψ residues were detected, which is rather close to the situation in Bacteria. However, three modified positions (Ψ2479, Ψ2535 and Ψ2550) are unique for S. acidocaldarius. Two Ψ residues at positions 2060 and 2594 are universally conserved, while one other Ψ (position 2066) is also common to Eucarya. Taken together the results argue against the conservation of Ψ‐synthases between Archaea and Bacteria and provide a basis for the search of snoRNA‐like guides for Ψ formation in Archaea.
Topography of neurochemical alterations in the CNS of aged rats
Authors: Virgili Marco , Monti Barbara , Polazzi Elisabetta , Angiolini Graziella , Contestabile Antonio
Published: July 2002

We have performed a general survey study on alterations of neurotransmitter‐related and glia‐related neurochemical markers in various regions of the CNS of aged (30‐month‐old) as compared to adult (4‐month‐old) rats. We have found significant decreases in the level of neurochemical parameters related to the cholinergic and GABAergic systems in several regions of the CNS of aged rats. Only few of the alterations present at the age of 30 months, were present in a group of rat of intermediate age (20 months) included in the present study. Less widespread alterations were found concerning the glutamatergic neurotransmission system. Neurochemical markers related to glial cells (astrocytes and oligodendrocytes) showed a remarkable stability in aged rats as compared to neurotransmitter‐related markers. Considering the various CNS areas examined in the present study, the spinal cord of the aged rats was the region showing the most profound alterations of neurochemical parameters, as compared to the various brain areas of the same rats. The present results suggest that moderate and region‐specific alterations of neurotransmitter‐related parameters occur during normal aging and that glia‐related markers are fundamentally stable in the absence of specific pathologies.
Neurobiologic basis of antidepressant safety profiles
Authors: Hackett D , Salinas E
Published: July 2002

Venlafaxine is a serotonin-noradrenaline reuptake inhibitor (SNRI) that has no affinity for muscarinic, adrenergic or histaminergic receptors. In short-term trials, the adverse effects that occurred more often with venlafaxine than with placebo included nausea, somnolence, dizziness, dry mouth, and sweating. Rapid titration of the dose of venlafaxine to higher levels appeared, not unexpectedly, to be associated with an increased incidence of side effects. Side effects that appeared to be dose related included insomnia, nausea and sexual dysfunction. The incidence of nausea and dizziness was highest during the first 2 or 3 weeks of therapy and decreased rapidly thereafter. Somnolence also decreased over time. At high doses blood pressure increases were reported in a small percent of patients on venlafaxine and antidepressant drugs but were uncommon at the venlafaxine dose of 75–150 mg daily. Studies with venlafaxine in healthy volunteers indicate a low potential for drug-drug interactions. Overdoses have been reported in 14 of 3,082 patients administered venlafaxine in clinical trials, and no deaths were reported among these patients. Overdoses of venlafaxine induced mainly drowsiness and lethargy.
Does education affect how well students forecast the market?
Authors: Alexander Jr. John C. , McElreath Robert B.
Published: July 2002

This study examines the results of a student stock market forecasting project used in our basic and advanced investments classes. Students fail to outperform a random walk model over the entire period, but do perform well in some subperiods. Students receiving an above average grade in the basic investments class provide more accurate forecasts than all other groups of students. Further, poorer performing students tend to be more pessimistic in their expectations of the market. The results suggest that education improves the forecasting ability of students. © 1999 Elsevier Science Inc. All rights reserved.
Applications of WWW technology in teaching finance
Authors: Michelson Stuart , Smith Stanley D.
Published: July 2002

In this article we discuss the need for a personal Web page in finance education, some of the ways Web pages can be used to benefit students, and present a survey of Web page use. We follow with a discussion of how to create and modify a Web page using commonly available computer programs. This information allows faculty the ability to provide valuable and timely information and materials for students. © 1999 Elsevier Science Inc. All rights reserved.
Liquidating a remainder interest
Authors: Bost John C. , Cherin Tony
Published: July 2002

There are many ways in which decedents leave property in trust for their heirs. One technique is to grant a life estate to surviving children. The purpose of this paper is to describe verbally, and through example, an approach to liquidating a life estate. This simplification in personal finance involves a “buyout” of the interests of the remaindermen. The result is dissolution of the trust, leaving the income beneficiaries to manage, as owner in fee, the remaining assets as they wish, without the expense and complexity associated with maintaining a trust. © 2000 Elsevier Science Inc. All rights reserved.
The effect of country-specific index trading on closed-end country funds
Authors: O’Connor Matthew , Downe Edward A.
Published: July 2002

The American Stock Exchange initiated trading in 17 World Equity Benchmark Shares (acronym “WEBS”TM) in April 1996. WEBS are index funds designed to track the Morgan Stanley Capital International (MSCI) indexes. We examine the effect of this event on closed-end country funds (CECFs) and find that percentage discounts increase. CECFs with a corresponding WEBS index experience the largest increase and also show a decline in trading volume. We attribute these results to (1) the effects of increased competition and (2) a reduction in the market segmentation premium. Since additional WEBS have begun trading, and other approvals may follow, similar effects could be experienced in the future. © 2001 Elsevier Science Inc. All rights reserved.
On time
Authors: Poole Barbara S.
Published: July 2002

This paper provides a brief review of the anthropology and psychology literature as it relates to time, an important variable in finance. First, the paper discusses ways that individuals represent time, and introduces cultural variations in the perception of time. Then the experience of time passing, and behavioral pace, is discussed. The succession of time and the orientation toward past, present, and future, are described. The paper may provide implications for academics whose finance research is related to behavior over time. © 2001 Elsevier Science Inc. All rights reserved.
Index Vol 9
Authors: Lahey Karen Eilers
Published: July 2002

NA
Personal Bankruptcy Costs
Authors: Ang James S. , Fatemi Ali M.
Published: July 2002

The paper argues that there is a need for the formal treatment of personal bankruptcy costs in thefinance literature. The need arises out of the relevance of such costs to both corporate and personal financing decisions. We show that (a) personal bankruptcy costs (like personal taxes) are relevant to the corporate capital structure problem and that (b) differential bankruptcy costs across corporations and individuals can result in a clientele model of individual investment-borrowing decision which could lead to insti- tutional arrangements designed to minimize combined bankruptcy costs. Further, we develop a theory ofpersonal bankruptcy and a set of testable hypothesis with regard to their costs. Some preliminary estimates of personal bankruptcy costs are reported which suggest that they are higher than corporate bankruptcy costs. There is also some evidence of economics of scale in personal bankruptcy costs.
Index Vol 7
Authors: Lahey Karen Eilers
Published: July 2002

NA
Modulators of histone demethylase JMJD1C selectively target leukemic stem cells
Authors: Yang Yong , Zhang Xinjing , Zhang Xiaoyan , Wang Yishu , Wang Xintong , Hu Linda , Zhao Yao , Wang Haihua , Wang Zhanju , Wang Haiying , Wang Lin , Dirks Wilhelm G. , Drexler Hans G. , Xu Xin , Hu Zhenbo
Published: December 2020

Leukemic stem cells (LSCs) comprise a very rare cell population that results in the development of acute myeloid leukemia. The selective targeting of drivers in LSCs with small molecule inhibitors holds promise for treatment of acute myeloid leukemia. Recently, we reported the identification of inhibitors of the histone lysine demethylase JMJD1C that preferentially kill MLL rearranged acute leukemia cells. Here, we report the identification of jumonji domain modulator #7 (JDM‐7). Surface plasmon resonance analysis showed that JDM‐7 binds to JMJD1C and its family homolog JMJD1B. JDM‐7 did not significantly suppress cell proliferation in liquid cell culture at higher doses, although it led to a significant decrease in semi‐solid colony formation experiments at lower concentrations. Moreover, low doses of JDM‐7 did not suppress the proliferation of erythroid progenitor cells. We identified that JDM‐7 downregulates the LSC self‐renewal gene HOXA9 in leukemia cells. We further found that the structure of JDM‐7 is similar to that of tadalafil, a drug approved by the US Food and Drug Administration. Molecular docking and surface plasmon resonance analysis showed that tadalafil binds to JMJD1C. Moreover, similar to JDM‐7, tadalafil suppressed colony formation of leukemia cells in semi‐solid cell culture at a concentration that did not affect primary umbilical cord blood cells. In summary, we have identified JDM‐7 and tadalafil as potential JMJD1C modulators that selectively inhibit the growth of LSCs.
Resection of piriform cortex predicts seizure freedom in temporal lobe epilepsy
Authors: Borger Valeri , Schneider Matthias , Taube Julia , Potthoff Anna‐Laura , Keil Vera C. , Hamed Motaz , Aydin Gülsah , Ilic Inja , Solymosi László , Elger Christian E. , Güresir Erdem , Fimmers Rolf , Schuss Patrick , Helmstaedter Christoph , Surges Rainer , Vatter Hartmut
Published: December 2020

Objective

Transsylvian selective amygdalo‐hippocampectomy (tsSAHE) represents a generally recognized surgical procedure for drug‐resistant mesial temporal lobe epilepsy (mTLE). Although postoperative seizure freedom can be achieved in about 70% of tsSAHE, there is a considerable amount of patients with persisting postoperative seizures. This might partly be explained by differing extents of resection of various tsSAHE target volumes. In this study we analyzed the resected proportions of hippocampus, amygdala as well as piriform cortex in regard of postoperative seizure outcome.

Methods

Between 2012 and 2017, 82 of 103 patients with mTLE who underwent tsSAHE at the authors’ institution were included in the analysis. Resected proportions of hippocampus, amygdala and temporal piriform cortex as target structures of tsSAHE were volumetrically assessed and stratified according to favorable (International League Against Epilepsy (ILAE) class 1) and unfavorable (ILAE class 2–6) seizure outcome.

Results

Patients with favorable seizure outcome revealed a significantly larger proportion of resected temporal piriform cortex volumes compared to patients with unfavorable seizure outcome (median resected proportional volumes were 51% (IQR 42–61) versus (vs.) 13 (IQR 11–18), P = 0.0001). Resected proportions of hippocampus and amygdala did not significantly differ for these groups (hippocampus: 81% (IQR 73–88) vs. 80% (IQR 74–92) (P = 0.7); amygdala: 100% (IQR 100–100) vs. 100% (IQR 100–100) (P = 0.7)).

Interpretation

These results strongly suggest temporal piriform cortex to constitute a key target resection volume to achieve seizure freedom following tsSAHE.