bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface Properties of Monomolecular Films of Reduced Plastocyanin at a Nitrogen-Water Interface
Authors: Brody Seymour Steven
Published: August 2018

The area/molecule (A) and surface potential (∆V) of reduced plastocyanin (pcyan) was measured as a function of pH. At pH 7.5 a maximum is observed for A while a minimum is ob­ served for ∆V. At a surface pressure of 5 dyn/cm the maximum A5 = 378 Å2 and minimum ∆V 5 = 335 mV. There is an interaction between pcyan and chlorophyll (Chi) in mixed films. As shown by a decrease of A and V compared to theoretically calculated volues. The largest decrease occurs at a mol ratio of about 2 pcyan: 1 Chl.

When mixed films are irradiated in air no changes in surface properties are observed.

Irradiation of mixed films of reduced pcyan and Chi in nitrogen results in a decrease in A and an increase of ∆V. The maximum decrease occurs at a mol ratio of pcyan/Chl between 1.5 and 2.0. The direction of change of A is consistant with a conversion of reduced pcyan to oxidized pcyan.
On the Origin of Protein Biosynthesis
Authors: Thomas B.R.
Published: August 2018

There is a very close steric relationship between the codon-anticodon site which accounts for the genetic code dictionary and a polynucleotide replicase site. Protein biosynthesis must therefore have arisen out of a primaeval polynucleotide replicase system.
Gefiederlipide der Ringeltaube Columba palumbus / Plumage Lipids from the Ring Dove (Columba palumbus)
Authors: Jacob Jürgen , Grimmer Gernot
Published: August 2018

Ring Only 6.7% of the whole plumage lipids of the ring dove originates from diester waxes of the uropygial gland secretion. The rest is distributed to hydrocarbons (3.3%), sterolesters and waxes (10.7%), free alcohols and sterols (5%), free fatty acids (55.6%), and unidentified material (18.7%). Among the hydrocarbons saturated odd-numbered, unbranched individuals predominate, but moreover 7-methylalkanes have been detected. The chain length of free and esterified alcohols cor­ responds to those of fatty acids where even-numbered compounds predominate. Main alcoholic component, however, is cholestanol.

The origin of these lipids is discussed.
The Separation of 32Silicon from Contaminating 3H and 60Co by Incorporation into Diatoms
Authors: Werner D. , Pawlitz H. D. , Roth R.
Published: August 2018

32Si (β-. 0,1 MeV, half life about 280 years) has been used, as for as we are aware, for the first time in bio­ logical and biochemical experiments . 32Si was incorporated by the pathway of the silicon metabolism into shells of two diatom species (Cyclotella cryptica and Nitzschia spec.) and reisolated by dissolving the shells. Contaminating isotopes 3H and 60Co with 10000 times more activity were largely removed by this procedure.
Determination of the Isotope Effect of the Enzymatic Oxidation of (R)Carnitine by Displacement of the Equilibrium via Mass Action
Authors: Brendel Klaus , Bressler Rubin , Alizade Miguel A.
Published: August 2018

An isotope effect of the dehydrogenation of (R) Carnitine [(R) 3-hydroxy-4-trimethylamino-butyric acid hydrochloride] catalyzed by (R) carnitine dehydrogenase [(R) carnitine: NAD oxido-reductase E.C. 1.1.1.108] from Pseudomonas aeruginosa was measured at different temperatures. It was found that k1H/k3H does not vary greatly with changes of temperature. The value of 3 for k1H/k3H measured at small initial conversions strongly indicated that the rate limiting step of the oxidation of (R) carnitine is the cleavage of the C-H bond at C3.
1,2,3-Thiadiazolyl-Pheny 1-Ureas, New Inhibitors of Photosynthetic and Respiratory Energy Conservation
Authors: Hauska G. , Trebst A. , Kötter C. , Schulz H.
Published: August 2018

Substituted 1,2,3-thiadiazolyl-phenyl-ureas were found to be inhibitors of energy conservation in respiration and photosynthesis. The most effective dichlorophenylderivative uncouples ATP formation in isolated chloroplasts or mitochondria, at a concentration of about 2 and 9 μм respectively. At a certain concentration range the compounds also appear to be energy transfer inhibitors, similar to the well known inhibition by carbodiimides. The significance of the chemical relation of carbodiimides to ureas in the mode of action on energy transfer is discussed. The thiadiazolyl-phenyl-ureas are inhibitors of electron flow only at relatively high concentrations, pointing out that sterig hindrance by two large aromatic rings at both nitrogens of the urea moiety abolishes the highly effective inhibition of photosynthetic electron flow by substituted urea derivatives, like DCMU.
An Autoradiographic Study of Neurosecretory Cell Activity of Allatectomized Females of the Grasshopper, Melanoplus sanguinipes (Fab.)
Authors: Dogra G. S.
Published: August 2018

Neurosecretory cell activity was studied autoradiographically in the allatectomized females of Melanoplus sanguinipes on every alternate day and in the normal control females on every fourth day for a period of 34 days. Experimental females exhibited five activity cycles against the two recorded by the control females. There was a comparatively high uptake of [3H] cystine by the neurosecretory cells of the experimental females on a particular day. During the first 12 days there was no accumulation of stainable colloid in their system. By the 24th day there was a slow and gradual accumulation of the colloids in the cells and their tracts so that on 34th day the system was well loaded with these colloids. In control females there was good accumulation of the stainable material during the first 12 days and then it declined so that 20 day old females had very little material in their system. This was followed by a massive accumulation of the stained colloids by 32nd day. The uptake of [3H] uridine was very high in the nerve-regenerate of the experimental females, and there were six cycles of secretory activity during the period of experimentation. The corpus allatum of control females, like their neurosecretory cells, exhibited only two activity cycles.

Since the activity of the neurosecretory cells parallels the RNA synthesis in the nerve-regenerate, it is postulated that the neurosecretory cells produce factors for nerve-regeneration. On the basis of high uptake of isotopes by the neurosecretory cells of those allatectomized females in which the oocytes were mature it is suggested that the hormone (s) produced by the neurosecretory cells are perhaps responsible for oocyte maturation in these allatectomized females.
Sensitivity of Escherichia coli to Viral Nucleic Acid, X. Ba2+-Induced Competence for Transfecting DNA
Authors: Taketo Akira
Published: August 2018

Effect of alkaline earth metal ions on induction of the competence for DNA transfection was investigated. Unlike spheroplasts, the bulk of the bacteria treated with these ions retains colony-forming ability. The order of effectiveness for transfection of ΦA replicative-form DNA has been found to be Ba2+>Ca2+>Sr2+>Mg2+. The competence of Ba2+-treated cells is 3 to 5 times higher than that of Ca2+-treated bacteria and about 40 times higher than that of lysozyme-EDTA spheroplasts. The Ba2+-dependent transfection is cryophilic and formation of the infective complex occurs very rapidly at 0 °C, but not at 37 °C.
Dissociation and Reassociation of Poliovirus I. Effect of Urea on the Virion
Authors: Drzeniek R.
Published: August 2018

Poliovirus is dissociated by urea in the presence of mercaptoethanol or dithiothreitol into RNA and protein (s). Differences exist in the sensitivity of poliovirus type I, II or III toward these agents. The decrease in infectivity titer of the virion is in the range of 109. After appropriate dis­ sociation no infectious virions are found in urea-treated poliovirus concentrates. The released viral RNA is infectious. Its infectivity (1 × 106 PFU/μg RNA) is comparable to that of phenol extracted RNA. Therefore, urea dissociation is a fast and reliable method for the preparation of infectious poliovirus RNA even at the microliter scale.

The dissociation of poliovirus is dependent upon the urea concentration, temperature and pH. The decrease in virion infectivity is time dependent. It is preceded by a lag phase of different lengths for poliovirus type I, II or III. During the lag phase the virion undergoes configurational changes without losing infectivity. From the observed hyperchromic effect it is obvious that the secondary structure of the RNA inside the virion breaks down, giving rise to expanded forms of poliovirus particles. After the lag phase the RNA is released and the empty capsid dissociated into the appropriate polypetides.
Synthesen von Phenylserinanaloga und deren tertiär-Butyloxycarbonyl-Derivaten / Syntheses of Phenylserin Analogues and Their t-BOC-Derivatives
Authors: Eisele K.
Published: August 2018

The syntheses of phenylserinanalogues and their t-BOC-derivatives are described. 3,4-Methylendioxy-phenylserine is a new amino acid.
Sequenzvariationen an einem antibiotisch wirksamen Tripeptid / Sequence Variation on an Antibiotically Active Tripeptide
Authors: Eisele K.
Published: August 2018

Seven tripeptides with the sequence L-Arg-ᴅ,ʟ-X-L-Phe were synthesised. Three of these peptides showed antibiotical activity on fungi. The amino- and the carboxylic terminus of the peptide L-Arg-ᴅ,ʟ-Phe-L-Phe, which showed antibiotical activity, were changed to give the sequences L-X-ᴅ,ʟ-Phe-L-Phe or L-Arg-ᴅ,ʟ-Phe-L-X respectively. The resulting tripeptides showed no antibiotical activity.
Affinitätschromatographie mit 125J-niarkierter RNA / Affinity Chromatography with 125J-labeled RNA
Authors: Kern Hartmut
Published: August 2018

Iodination of RNA with carrier-free 125J changes the affinity to cellulose and polyuridylic acid. Because part of the radioactive RNA is tenaciously bound to the respective matrix [125J]RN A cannot be used for affinity chromatography.
Neuram inidase Treatment Enhances the Lysolecithin Induced Intercellular Adhesion of Amoeba proteus
Authors: Ray P. K. , Chatterjee S.
Published: August 2018

Egg lysolecithin induces intercellular adhesion of Amoeba proteus. Pre-treatment of cells with Vibrio cholerae neurami­ nidase (VCN) increases the adhesive property of cells as was evidenced in their formation of larger cell aggregates than controls. A possible role of VCN exposed receptor sites in cellular adhesion is suggested.
Spectrophotometric Determination of the pK Values for Dissociation of the Sugar Hydroxyls in Pyrimidine Arabinonucleosides
Authors: Darżynkiewicz Edward , Sierakowski Henryk , Shugar David
Published: August 2018

Arabinonucleosides, Spectrophotometric Titration, Sugar Hydroxyl Dissociation Spectrophotometric titration in the ultraviolet has been employed to determine the pK values for dissociation of the sugar hydroxyls in pyrimidine arabinonucleosides and some of their O′-methyl and O′-ethyl derivatives.

The order of dissociation of the sugar hydroxyls in the arabinofuranose ring was 2′-OH > 3′-OH > 5′-OH. The higher acidity (lower pK) of the 2′-OH was interpreted in terms of formation of an intramolecular hydrogen bond of the form 5′-OH···2′-O(-) and the accompanying changes in conformation of the arabinose ring.

The various factors affecting the dissociation of specific hydroxyls in some of the O′-alkyl derivatives are discussed in relation to steric, conformational and other effects.
Chemoelastic Effect of Membranes
Authors: Gruler Hans
Published: August 2018

The elastic theory of a uniaxial membrane in an asymmetric environment predicts a spontaneous splay deformation. This spontaneous curvature of the membrane is discussed by the intrinsic splay of the membrane molecules (e. g. wedge shaped molecules) and their polar orientation. The chemoelastic effect is the polar orientation induced by the asymmetric environment in connection with the intrinsic splay. This effect is also discussed for polyelectrolytes where a small change of pH (~0.1) can lead to a spontaneous curvature of 104 cm-1. The actual shape of red blood cells can be explained by the spontaneous splay and a change in environment induces the change in shape of these cells. A model is proposed for two conical bodies swimming in a uniaxial membrane which interact with each other through elastic coupling. The force between the bodies can be either attractive or repulsive. As an example of this model clustering of proteins is discussed.
Determination of the Molecular Weight and the Hydrodynamic Properties of a Polypeptide from the Thylakoid Membrane by Sedimentation, Diffusion and Binding Measurements in Dodecyl Sulphate Solutions
Authors: Craubner Hans , Koenig Friederike , Schmid Georg H.
Published: August 2018

The molecular weight and hydrodynamic properties of a polypeptide isolated from the lamellar system of Antirrhinum chloroplasts were determined in sodium dodecyl sulphate solution by measurement of sedimentation velocity, diffusion and effective partial specific volume. The polypeptide fraction exhibits a molecular weight of 25 000 which agrees with the apparent molecular weight found by polyacrylamide gel electrophoresis. The molecular weight of the polypeptidesodium dodecyl sulphate micelle was 54 000, with a friction ratio of 1.6 which indicates an effective asymmetric hydrodynamic shape. For binding measurements self-diffusion equilibrium dialysis with dodecyl [35S] sulphate was used. In this case, dialysis equilibrium was reached within about 10 hours, in contrast to the dialysis with initial concentration differences which requires much longer times. A binding value of δD = 1.15g sodium dodecyl sulphate per g polypeptide was obtained which corresponds to a molar binding ratio of 100 mol dodecyl sulphate bound per mol of polypeptide. After the removal of dodecyl sulphate the polypeptide is present in an aggregated state. In phosphate buffers of pH 6.8 and 7.5 the aggregates preponderantly have sedimentation coefficients of 11.7 and 6.8 Svedberg units respectively. Assuming equivalent spheres the molecular weights were calculated to be 340 000 and 150 000.
Solubilisierung von "High Potential" Cytochrom b-559 aus Spinat-Chloroplasten
Authors: Lach Hans-Joachim , Böger Peter
Published: August 2018

1. Ethanol-extracted spinach chloroplasts were carefully sonified in a mixture of buffered urea, TRITON X-100 and dithiothreitol. This procedure solubilized the membrane-bound b-type cytochromes 559 and 563 to approx 90%. The crude extract contained both the high-potential (HP) and the low-potential form (LP) of cytochrome b-559 in a molar ratio of 1:1.

2. Strong sonification doubled the amount of low potential cytochrome b-559 in the extract. There­fore, it is assumed that Cyt b-559 HP was completely converted into the low-potential form.

3. Cyt b-563 was solubilized in the same concentration by both methods.

4. In the same medium (see No. 1), cytochrome f (= Cyt c-554) was dissolved by strong sonification only and is then essentially present in the extract in a dithionite-reducible form.
Inquiry into the Limits of Biological Effects of Chemical Compounds in Tissue Culture, I
Authors: van Mansvelt Jan Diek , Amons Ferdinand
Published: August 2018

Experiments were designed to investigate the low-dose side of the so-called dose-effect relation of mercuric chloride on the proliferation of a murine lymphoblastic cell strain (MB VIa). Three concentration ranges, from 0.9 × 10-5 м to 0.9 × 10-18 м, from 0.9 × 10-12 м to 0.9 × 10-25 м , and from 0.9 × 10-15 м to 0.9 x 10-21 м, in which the concentration decreased stepwise by a factor 10, were studied in 61, 74 and 58 experimental repetitions, respectively.

In the first range, the concentrations 0.9 × 10-5 M and 0.9 x 10-6 м HgCl2 proved to be definitely toxic as was expected. However, also 0.9 × 10-16 м and 0.9 × 10-17 м appeared to be growth-inhibiting, the latter results being confirmed in the second and the third concentration ranges. These differences in cell growth were statistically significant.
The Presence of Disparlure, the Sex Pheromone of the Gypsy Moth, in the Female Nun Moth
Authors: Bierl B. A. , Beroza Morton , Adler V. E. , Kasang G. , Schneider D. , Schröter H.
Published: August 2018

Disparlure, (cis-7,8-epoxy-2-methyloctadecane) the sex attractant of the gypsy moth, Porthetria (Lymantria) dispar, attracts the male nun moth, Lymantria monacha, in the field and is a highly effective olfactory stimulus in electroantennogram (EAG) and single-cell recordings. We have now analyzed the extract of 2000 abdominal tips of the female nun moth. Physical and chemical tests, which included gas-chromatographic retention times, elution volumes from silica gel and silica gel-silver nitrate columns, mass spectra, epoxide functionality, EAG-activity of chromatographic fractions with gypsy moth antennae, presence of disparlure precursor, all indicated that disparlure is present in the extract of nun moth sex glands. The optical activity of the natural disparlure of the two species has not yet been determined. Several authors have reported 1-0 that disparlure,
Temperature – Jump Chlorophyll Fluorescence Induction in Plants
Authors: Schreiber Ulrich , Colbow Konrad , Vidaver William
Published: August 2018

In contrast to slower heating rates, a temperature jump reveals complex rise phases in the heat induced chlorophyll fluorescence emission increase in intact plants. Three rise phases have been detected which indicate the stepwise loss of different quenching mechanism of system II fluorescence. Two of the phases appear to reflect heat deactivation of the system II reaction centers, while the other may be associated with the induction of hydrogenase activity. Variations in Tmax of the jump, for the increase in different plant varieties, suggest a correlation with membrane lipid phase transitions affecting thylakoid membrane structure and the fluorescence increase.
Zur Optik des Flußkrebsauges / Optics of the Crayfish Eye
Authors: Vogt Klaus
Published: August 2018

Physiological Optics, Crustacean Superposition Eye Histological and optical observations in the eye of crayfish lead to a new hypothesis of the superposition ray path in this eye. Rays from an object point entering through different facets are superimposed not by refracting systems as in other superposition eyes but by a radial arrangement of orthogonal reflecting planes which are formed by the sides of the crystalline cones and purine layers surrounding them.
Correlation of the Photosynthetic Reduction of ρ-(Diazonium-)Benzenesulfonic Acid with the Increased Binding of the Probe to the Thylakoid Membrane
Authors: Lockau Wolfgang , Selman Bruce R.
Published: August 2018

The reactions of chloroplast thylakoid lamellae with the chemical probe ρ-(diazonium-) benzene­ sulfonic acid (DABS) in the light have been reinvestigated. In contrast to a previous report, electron transport from a photosystem I electron donor to methylviologen was found to be inhibited by this treatment. During the incubation of chloroplasts with DABS in the light, the probe is altered with high rates. Under aerobic conditions, a concomitant oxygen uptake is observed, which is stoichiometric to the amount of DABS altered. Under anaerobic conditions, the binding of the 35S-labeled probe to the membranes in the light is stimulated 2 - 3 fold as compared to the binding under aerobic conditions. The data are taken as evidence that the photoreduction of the probe rather than a conformational change of the membrane may be at least partially responsible for the increased reagent binding observed in the light.
Größenvergleich der Poly(A)-RNA aus Polysomen und aus Kernen bei der Hefe Saccharomyces cerevisiae / Size Comparison of Poly (A )-RNA from Polysomes and from Nuclei of the Yeast Saccharomyces cerevisiae
Authors: Angermann Kornelia , Grundmann Ulrich , Holz Hartmut
Published: August 2018

The size of poly(A)-RNA from polysomes and cell nuclei of the yeast Saccharomyces cerevisiae was investigated. Pulslabelled cells ([14C]adenin) were cracked by the French press; polysomes and nuclei were separately isolated and the RNA was finally extracted with phenol. The separation of poly (A)-containing and poly (A)-lacking fractions was achieved by oligo (dT) cellulose. These fractions were characterized by sedimentation analysis. The main portion of polysomal poly (A) -RNA sedimented with a rate of 8 to 14S, whereas the poly (A)-RNA of nuclei exhibited a sedimentation rate of 12 to 17S. Thus nuclear poly (A)-RNA is about 20 -30% larger than polysomal poly (A) -RNA.
Synthesis of Purine and Pyrimidine Substituted Nitroxides
Authors: Harcus R , Preston P.N. , Suffolk J.S.
Published: August 2018

Reaction of 6-hydrazinopurine and 2-hydrazinopyrimidine with 2,2,6,6-tetramethylpiperidone-1-oxyl gives 2,2,6,6-tetramethylpiperidone- 1-oxyl-(6-purinyl)hydrazone (3b) and 2,2,6,6- tetramethylpiperidone-1-oxyl- (2-pyrimidinyl) hydrazone (4b) respectively. Compound 3b is inactive even at high dose levels against TLX/5 lymphoma and 3b and 4b are both inactive in tests using the L1210 leukaemia system.
Reversal of Dibromothymoquinone Inhibition of Photosynthetic Electron Flow by Thiol Compounds
Authors: Reim S. , Trebst A.
Published: August 2018

Dibromothymoquinone inhibits photosynthetic NADP reduction by broken chloroplasts. The inhibition of electron flow and coupled ATP formation is effectively reversed by the addition of thiol compounds.
New and Uncommon Indole- and Imidazole-Alkylamines in Skins of Amphibians from Australia and Papua New Guinea
Authors: Roseghini M. , Endean R. , Temperilli A.
Published: August 2018

Extracts of the skin of some amphibians from Australia and Papua New Guinea contained, in addition to the usual 5-hydroxyindolealkylamines and histamine: a. two new, hitherto unknown indolealkylamines, i.e . O-sulphate of bufotenidine and 2-(3-indolyl)ethyltrimethylammonium, a quaternary ammonium base of tryptamine. The rare O-sulphate of bufotenine was also present, the occurrence of which had previously been demonstrated only in the skin of some South American toads; b. a series of uncommon imidazolealkylamines, such as N′-acetylhistamine, N′-methyl-histamine, N′,N′-dimethylhistamine, spinaceamine and 6-methylspinaceamine. It appears evident that amphibian skin continues to be an exceptionally rich source of aromatic amines.
Particle Movement in Heliozoan Axopods Associated with Lateral Displacement of H ighly Ordered Membrane Domains
Authors: Bardele Christian F.
Published: August 2018

Freeze-fracture studies reveal that extrusive organelles displaying saltatory particle movements in centrohelidian axopod are attached to highly ordered domains within the plasma membrane. It is postulated that the motive force for lateral displacement of these membrane domains with the adhering organelle is located immediately underneath the plasma membrane being either part of the peripheral membrane proteins or attached filaments alined parallel to the axopodial micro­ tubules. The attachment domain is interpreted organelle discharge by membrane fusion.
Notizen: Differential Migration of Foliar Applied Zinc in Maize Plants
Authors: Kannan Seshadri , Keppel Hans
Published: August 2018

The mobility of Zn2⊕ was assessed by supplying 65Zn2⊕ to the different leaves of maize plants, and radioassaying the plant parts after 2 days. It was found that the 3rd leaf (from the base) absorbed more Zn2⊕ than other leaves. A larger percentage of Zn2⊕ transported, was identified in the stem in general. The study further revealed that there was a close link between the 1st and the 4th leaf for the transport of Zn2⊕
Notizen: Neue Anthrachinonfarbstoffe aus Solorina crocea / Novel Anthraquinone Pigments from Solorina crocea
Authors: Steglich W. , Jedtke K.-F.
Published: August 2018

Besides the known pigments solorinic acid (1) and norsolorinic acid (2) the lichen Solorina crocea contains 4.4′-disolorinic acid (3), averantin 6-methyl ether (4), and averantin (5).
Studies on the Undecapeptide of Ferricytochrome c Using ESR, Mössbauer and Visible Spectroscopies
Authors: Nassif Sr. Rosemarie , Baumgartner Celia , Sellers Martha , May Leopold
Published: August 2018

Undecapeptide of Ferricytochrome c, Electron Spin Resonance, Mössbauer Spectroscopy, Visible Spectroscopy The ESR, Mössbauer, and visible spectra of the undecapeptide of ferricytochrome c (H P p) were measured for both the solid peptide and solutions of the peptide at pH 1.5, 7, and 10. At the low pH, the iron exists in the H Pp in the high-spin species. At neutral and alkaline pHs, the low-spin ferric species predominate. The results of these measurements support the previous sug­gestions concerning the ligands in the fifth and sixth position of HPp at the neutral and alkaline pHs. The spectra of lyophilized preparations of HPp show the presence of both high and low-spin ferric species. The study of the Mössbauer spectra of the lyohilized preparations as function of temerature shows that there exists a spin-spin equilibrium between the two spin states. The relative amounts of the two components vary with the preparation. In these preparations there exist two components, one of which exists in the equilibrium mixture and the second in the high-spin form.
Röntgenkleinwinkel-und Sedimentationsstudien am a-Häm ocyanin Helix pomatia (halbe Moleküle) in Glycerin-und Saccharoselösungen / Small-Angle X-Ray and Sedimentation Studies on a-Haemocyanin H . pomatia (Halve Molecules) in Glycerol and Sucrose Solutions Small-Angle X-Ray Scattering, Haemocyanin, Sedimentation, Multicomponent System
Authors: Berger Johann , Pilz Ingrid , Witters Raf , Lontie René
Published: August 2018

The α -haemocyanin molecules of Helix pomatia were decomposed into halves and studied in solution by small-angle X-ray scattering. The following parameters of the molecule could be ob­tained : radius of gyration, volume, molecular weight, overall shape and dimensions of the molecule.

With small-angle X-ray scattering fluctuations of the electron density within the protein cause parasitic scattering at larger angles. According to Stuhrmann and Kirste it is possible to eliminate it mathematically by varying the electron density of the buffer. For this purpose different quan­tities of glycerol respectively saccharose were added to the solvent to study the scattering of α -haemocyanin halves in solvents of varied electron density. The change of the isopotential specific volume of haemocyanin and the strong increase of the statistical errors of its scattering by de­creasing of the excess scattering of solution over solvent per unit volume did not allow an ap­plication of the method of Stuhrmann and Kirste. The data obtained for α -haemocanin halves in different solvents are given.

Besides also the sedimentation of the α -haemocyanin halves were studied in solutions containing varied amounts of glycerol and saccharose. An attempt was made to calculate the change of the partial specific volume of haemocyanin by adding glycerol or saccharose.
Synthesis and Herbicidal Activity of d (+) and 1(–) Methyl-2-chloro-3-(4-chlorophenyl)-propionate
Authors: Schmidt Th , Ag Bayer , Forschungszentrum Wuppertal , Fedtke C , Schmidt R , Schmidt Th. , Fedtke C. , Schmidt R. R.
Published: August 2018

d (+) and 1(-) Methyl-2-chloro-3-(4-chlorophenyl)-propionate (common name chlorfenprop-methyl; trade mark Bidisin®) were prepared and their herbicidal activities studied on Avena fatua L. and Avena sativa L. (“Flämingskrone”). The 1(-) enantiomer was found to be twice as active as the racemate; the d (+) form almost inactive.
The Use of 1-Anilino-8-naphthalene Sulfonate as Fluorescent Probe for Conformational Studies on Ribulose-1,5-bisphosphate Carboxylase
Authors: Wildner G.
Published: August 2018

The influence of Mg2+ ions and temperature on the structure of the enzyme ribulose-1,5-bisphosphate carboxylase was investigated using the fluorescent probe 1-anilino-8-naphthalene sulfonate (ANS). The binding of ANS to the enzyme molecule caused a significant increase of fluorescence emission which was further enhanced by the addition of Mg2+. The temperature dependence of the fluorescence emission indicated a conformational change of the enzyme between 12 and 24 0C. The Mg2+ and the temperature effects were additive. ANS itself did not change the conformation of the enzyme. The influence of the substrates carbon dioxide and ribulose-1,5-bisphosphate, and the effect of the pH of the medium and of a sulfhydryl reducing reagent on fluorescence emission were analysed.
Properties of an Antiserum Against Streptomyces hydrogenans 20β-Hydroxysteroid Dehydrogenase
Authors: Lotz Bernhard , Betz Joachim , Träger Lothar
Published: August 2018

Antiserum against crystallized 20β-hydroxysteroid dehydrogenase from Streptomyces hydrogenans was used for different immunodiffusion and immunoprecipitation tests to quantify the bacterial enzyme in cell-free supernatants of the microorganism. After immunoprecipitation and gel electrophoresis the molecular weight of the subunits of 20β-hydroxysteroid dehydrogenase was calculated to be 27 300 ± 700.
Pyramidal Cells with Different Densities of Dendritic Spines in the Cortex of the Mouse
Authors: Schüz Almut
Published: August 2018

Neighbouring pyramidal cells in the mouse cortex sometimes have different densities of dentritic spines. This was shown by a quantitative analysis of 10 neurons. For this, a method was worked out which corrects for the spines hidden behind (and in front of) the dendrite. The main result is that there is a positive correlation between the spine densities on different parts of the dendritic tree of one neuron. The possible functional meaning of these findings is briefly discussed.
Tautomerism of Isoguanosine and Solvent-Induced Keto-Enol Equilibrium
Authors: Sepioł Jerzy , Kazimierczuk Zygmunt , Shugar David
Published: August 2018

Ultraviolet and infrared absorption spectroscopy, in aqueous and non-aqueous media, have been employed to study the tautomerism of 9-substituted isoguanines, including the nucleoside iso­ guanosine. With the aid of a series of model compounds, it was shown that 9-substituted isogua­ nines, and isoguanosine, in aqueous medium are predominantly in the form N(1)H,2-keto-6-amino.

In dioxane solution the tautomeric equilibrium is shifted in the direction of the enol form. The shift towards this form is accentuated for those analogues in which the exocyclic amino group is methylated.

With the aid of N6,N6,9-trimethylisoguanine, and its 9-octyl analogue, the tautomeric constant was studied as a function of concentration, temperature, and solvent polarity, and the results applied to evaluate the tautomeric equilibria of 9-methylisoguanine and isoguanosine as a function of these variables. In general the enol form is favoured by a decrease in solvent polarity, by a decrease in concentration in dioxane, or an increase in temperature in chloroform solution.

Syntheses are described for several N6-amino and methylamino derivatives of 2-methoxy-9-methylpurine, and 3-methyl-5-oxo-7,8-dihydroimidazo (2,1-i) purine, which served as an analogue of the unavailable 1,9-dimethylisoguanine.
Synthese von 5-Azido-3-nitro-ω-brom-acetophenon — einem photoaktivierbaren bifunktionellen Reagenz zur Vernetzung von Biopolymeren / Synthesis of 5-Azido-3-nitro-ω-bromo-acetophenone — a Photochemically Active Bifunctional Reagent for the Cross-Linking of Biopolymers
Authors: Seela Frank
Published: August 2018

The photochemically activatable heterobifunctional reagent 5-azido-3-nitro-ω-bromo-acetophenone (3) was synthesized by condensation of 3,5-dinitrobenzoyl chloride with diethyl malonate, acid-catalyzed decarboxylation of the formed malonester derivative 1 to 3,5-dinitro-acetophenone (2a), selective reduction of one nitro group in 2a to 5-amino-3-nitro-acetophenone (2b) and diazotization to 2c. Nucleophilic displacement of the diazonium group in 2c by sodium azide forms 5-azido-3-nitro-acetophenone (2d) which gives 3 after bromination. Compound 3 is photochemically labile and forms an highly reactive nitrene during ultraviolet irradiation. Since compound 3 is able to alkylate amino-or mercapto-groups of amino acids or nucleosides via its bromoacetyl residue, the bifunctional reagent 3 should cross link proteins or nucleic acids after nitrene generation.
Weitere Anthrachinone aus Digitalis schischkinii, X / Further Anthraquinones from Digitalis schischkinii
Authors: Imre Sedat , Öztunc Aysel
Published: August 2018

Twentyone anthraquinones have been found in the roots of Digitalis schischkinii (Ivan.) of which the following are new natural pigments: 4,5-dihydroxydigitolutein, 5-hydroxy-and 4,5-dihydroxy-nordigitolutein.
Enzymatischer Abbau von [Ring B-U-14C]-5.7.3′.4′-Tetrahydroxy- flavanon-7-O-glucosid zu 5.7-Dihydroxychromon-7-O-glucosid und [Ring-U-14C]-1.2.4-Trihydroxybenzol mit einem zellfreien Extrakt von Mentha longifolia / Enzymatic Degradation of [Ring B-U-14C] -5,7,3′,4′-tetrahydroxyflavanone-7-O-glucoside to 5,7-Dihydroxychromone-7-O-glucoside and [Ring-U-14C]-1,2,4-trihy-droxybenzene with a Cell Free System from Mentha longifolia
Authors: Janistyn Boris , Stocker Martha
Published: August 2018

[Ring B-U-14C]-5,7,3′,4′-tetrahydroxyflavanone-7-O-glucoside could be synthesized and a new way of flavanone-degradation is demonstrated. The B-ring is split off under formation of 5,7-dihydroxychromone- 7-O-glucoside and [ring-U-14C]T,2,4-trihydroxybenzene.
Studies on Plant Bile Pigments: Characterization of a Model for the Phytochrome Pr Chromophor
Authors: Scheer Hugo
Published: August 2018

The common A-dihydrobiliverdin chromophor proposed to be present in both phycocyanin and phytochrome Pr has been characterized by using octaethylbiliverdin and its A-dihydro derivative as model compounds. The UV-vis spectra for the free bases, cations, anions and zinc complexes are reported, and the related protonation-deprotonation equilibria have been studied. The data support the postulated structures for the biliproteid chromophor, and at the same time they indicate A-dihydrooctaethylbiliverdin to be a useful model.
Aminotransferase-Aktivität in der Blaualge Anacystis nidulans / Activity of Aminotransferases in the Blue Green Alga Anacystis nidulans
Authors: Döhler Günter
Published: August 2018

The blue-green alga Anacystis nidulans (strain L 1402-1) was grown at + 37 °C in air (0.03 vol.% CO2 and in air enriched with 3.0 vol.% CO2. The effects of several inhibitors on the activity of aminotransferases, 14CO2 fixation and radioactive photosynthetic products of Anacystis were studied. No serine-pyruvate aminotransferase activity could be found in 10-2 м isonicotinyl hydrazide (INH) ; under the influence of this inhibitor aspartate and alanine aminotransferase were decreased about 49% respectively 17.6%. Serine-pyruvate and alanine aminotransferase activity decreased to more than 50% in 10-3 м glyoxalbisulfite. The obtained inhibitory effect of 10-4 м HPMS on serine-piruvate aminotransferase (35%) was stronger than on the other aminotransferases. DCMU (5 × 10-6 м) inhibition on alanine aminotransferase activity was 83.7%. Under the influence of 10-3 м glyoxalbisulfite no 14C-labelled amino acids could be detected after 5 min photosynthesis; 14C-labelling of phosphoenolpyruvate, malate, phosphoglycolate and glycolic acid increased. Isonicotinyl hydrazide (10-2 м) caused in comparison to the control experiment a lower radioactivity in aspartate, glutamate and phosphoenolpyruvate. The results are discussed with reference to the operation of the glycolate pathway and a carboxylation reaction of phosphoenolpyruvate in the blue-green alga Anacystis nidulans.
Stabilization of the Photosynthetic Activities of Isolated Spinach Chloroplasts during Prolonged Ageing
Authors: Kulandaivelu G. , Hall D.O.
Published: August 2018

Isolated spinach chloroplasts (type A complete) were used to study the changes in the photo-chemical activities upon storage in order to establish optimum conditions for prolonged storage. Chloroplasts stored at - 5 °C were found to retain over 70% of their photosynthetic electron transport from H2O even after 5 days. Increases in the level of state 2 electron transport (due to uncoupling) with concomitant loss of state 3 phosphorylation activity was observed during the initial period of ageing. Addition of 1% bovine serum albumin decreased the level of uncoupling and maintained the phosphorylation activity for a longer period. Chloroplasts stored at 77 °K maintained their phosphorylation capacity for a period of 10 days even after repeated freezing and thawing. Photosystem I activity was found to be more stable over the whole ageing period of 15 days. Loss of plastoquinone may be responsible for the decrease in electron transport between photosystems II and I.
Untersuchungen an Rektalpolstern der Honigbiene Apis mellifica / Studies on the Rectal Pads of the Honey Bee Apis mellifica
Authors: Bazin Brita , Kümmel Georg , Zerbst-Boroffka Irene
Published: August 2018

Honey Bee, Rectal Pads, Function According to earlier investigations young bees show a rectal fluid hypo-osmotic to the haemolymph. It had been assumed, however, that in certain situations honey bees have to be economical with water and simultaneously form a rectal fluid hyperosmotic to the haemolymph. The latter has been confirmed by the present investigation.
Functional Characterization and Anatomical Identification of Motion Sensitive Neurons in the Lobula plate of the Blowfly Calliphora erythrocephala
Authors: Hausen K.
Published: August 2018

8 classes of homo- and heterolateral wide field neurons of the Lobula plate of Calliphora erythrocephala were investigated electrophysiologically and identified by intracellular injection of procion yellow. All recorded neurons were motion-sensitive. Some of the homolateral neurons respond only with graded potentials to visual stimulation; all heterolateral elements generate spike potentials. Connections between identified neurons were investigated by means of simultaneous double recordings. The described neurons are compared with units known from earlier extracellular studies.
Chemical Composition of the Nasal Gland Secretion from the Marsh Deer Odocoileus ( DorcelaphusJ dichotomus (Illiger)
Authors: Jacob Jürgen , Von Lehmann Ernst
Published: August 2018

The secretion of the nasal gland from the marsh deer (Odocoileus dichotomus) has shown to be a lipid mixture predominantly containing cholesterol esters, mono-and diester waxes, the latter of which containing 2-hydroxy fatty acids. The alcoholic constituents of the mono-and diester waxes contain considerable amounts of mono-unsaturated homologues, all with double bonds in(ω-9) position.
Unusual Photochemical Transformation of 5-Ethylorotate to 5-Ethylidenehydroorotate
Authors: Kulikowska E , Hingerty B , Saenger W , Shugar D
Published: August 2018

Ultraviolet irradiation of 5-ethylorotate in aqueous medium led to formation of 5-ethylidene-hydroorotate via a 1,3-hydrogen rearrangement from the ethylene group of the 5-substituent to the ring C6 . The same product was also obtained by an alternate pathway via a hitherto un­identified intermediate.

The structure of this unusual pyrimidine analogue, established in the solid state by X-ray diffraction, was shown with the aid of spectroscopic methods to be the same in solution, and some of its properties are described.

Heating of 5-ethylidenehydroorotate in the solid state led by direct conversion to a mixture of the parent 5-ethylorotate and 5-ethyluracil. By contrast, ultraviolet irradiation in aqueous medium resulted in quantitative photochemical conversion of the photoproduct to 5-ethyluracil.
Spectral Properties of Fluorescent Dyes in Lecithin Vesicles
Authors: Pohl G. W.
Published: August 2018

Three fluorescent dyes (a merocyanin, a cyanin and a modified umbelliferon) have been in­corporated into vesicles from three different lecithins. Their absorption spectrum, emission spectrum and fluorescence polarization in the lipid vesicles has been studied and compared with the spectral properties in homogeneous organic solutions. The reactivity of lipid bound dyes with reagents in the aqueous phase was investigated. The location use as indicators of phase transitions or membrane
Variable Composition of Cytochrome b6-f Particles
Authors: Lach Hans-Joachim , Böger Peter
Published: August 2018

Cytochrome b6-f particles were prepared from chloroplasts of spinach and the heterokont alga Bumilleriopsis filiformis using digitonin in comparison with non-ionic detergents. The cytochrome b6-f particles are solubilized in different amounts according to chemical structure and HLB value of the detergent (see Griffin, J. Soc. Cosmet. Chem. 1, 311 [1949]). Also the ratio of the two cytochromes in the isolated particle depends on the detergent used. In case of spinach, it varies from Cyt b6: f = 1.5:1 to 4.9:1. These investigations do not strengthen the idea that a cytochrome b6-f complex with a stoichiometric composition is present in the photosynthetic membrane. Applica­tion of different detergents is a means for selective solubilization of thylakoid membrane com­ponents.
Notizen: Eine besondere Haftvorrichtung zwischen Cortex radiatus externus und Follikelepithel der Oocyten von Gobio gobio (L). (Teleostei, Cyprinidae)/A Special Attaching-Mechanism between the Cortex radiatus externus and the Follicle Epithelium of the Oocytes of Gobio gobio
Authors: Riehl Rüdiger
Published: August 2018

The cortex radiatus externus and the follicle epithelium of the freshwater teleost Gobio gobio are firmly attached together by a special attaching-mechanism. The apical surface of the plugs of the cortex radiatus externus has recesses and excavations which fit in the short projections of the follicle cells and prevent moving of these cells on the egg mem­branes. This attaching-mechanism also assists in fastening the oocytes (eggs) on the substrate.
Interaction of Streptolysin-O with Natural and Artificial Membranes
Authors: Fehrenbach Franz J. , Eibl Hansjörg
Published: August 2018

1. Kinetic studies on the binding of 125I-Streptolysin-O exhibited immediate fixation of activated toxin to natural and artificial membranes. Once fixed to the membrane no release of Streptolysin-O or Streptolysin-O-lipid-complexes has been observed.

2. In contrast to activated toxin (free SH-groups!), oxidized Streptolysin-O was shown to become also fixed to membranes, however, with different binding kinetics. The binding of oxidized material was clearly dependent on temperature and time. When the toxin was oxidized twice the amount of labelled material was bound as compared with the hemolytically active Streptolysin-O. This suggests that oxidized Streptolysin-O, too, possesses a “binding site” within the molecule, though free SH-groups were expected to be essential for toxin fixation at the membrane. It has been shown that oxidized (inactive) and reduced (active) Streptolysin-O forms stable “complexes” with liposomes in aqueous solution, which could be separated by chromatography on Sepharose gels.

3. The binding of 125I-toxin to membranes and liposomes was specific since specific antisera against Streptolysin-O inhibited fixation of toxin completely.

4. Hydrolysis of phospholipids and release of lysophosphatides by Streptolysin-O esterase (EC 2.1.1.2) has not been observed, thus providing no evidence for an enzymatic concept of membrane damage.
The Effect of Water on Proton Transfer in Pyrazole
Authors: Babin V. N. , Zavelovich E. B. , Belousov Yu. A.
Published: August 2018

An NMR 13C study has shown that proton rearrangement in pyrazole is decreased by adding small amounts of water to the sample. Single water molecules as coordination centres pertrub the mechanism of cooperative proton transfer occurring in pyrazole selfassociates. The decrease of the rearrangement effect due to water is similar to the action of transition metal ions studied by the authors earlier.
Schadstoff-Untersuchungen an datierten Sedimentkernen aus dem Bodensee / Pollution Research on Dated Sediment Cores from Lake Constance
Authors: Müller German
Published: August 2018

The vertical distribution of nitrogen and phosphorus in dated sediments of four sedimentary profiles from the central part of Lake Constance was examined.

From about 1900 until now a steady increase of N and P is to be observed. Nitrogen is enriched by a factor of about 5, phosphorus by a factor of about only 2. The N/P-ratio shows a continuous increase since 1900.

The explanation for this development is the steady increase of phosphates delivered into the lake since about 1900. Thus, p.ex. the total amount of phosphorus increased between 1930 and 1974 from 274 to 1929 tons per year.

Most of the sedimentary nitrogen is incorporated into the organic material, the production of which is clearly bound to the availability of phosphorus in the lake water. Phosphorus is mostly found in an adsorbed position on clay minerals.

Between N and P on one hand and certain heavy metals (Cd, Zn) and polycyclic aromatic hydrocarbons on the other hand a positive correlation only can be found as long as the curves for phosphate delivery (responsible for N-and P-concentrations) and coal consumption (responsible for certain heavy metals and polycyclic aromatic hydrocarbons) have a parallel development.

The decrease in coal consumption in connection with a very strong increase of phosphate delivery during the past 15 years has ceased the parallel evolution of the different groups of pollutants in the sediments, and also demonstrates, that a causal relationship N and P - heavy metals and polycyclic aromatic hydrocarbons does not exist.
Isolation and Characterization of a Potassium Specific Ionophore from Streptococcus fuecalis
Authors: Kanne Reinhard
Published: August 2018

The synthesis of a potassium and rubidium specific ionophore by Streptococcus faecalis has been proved, using bilayer measurements. The characteristics of this substance agree with the ones, published for free mobile carriers, such as valinomycin and the macrotetrolides.
Sensory Efficacy of Alkyl-Branched Pheromone Analogues in Noctuid and Tortricid Lepidoptera
Authors: Priesner Ernst , Bestmann Hans-Jürgen , Vostrowsky Otto , Rösel Peter
Published: August 2018

The effect of introducing alkyl substituents (methyl to pentyl) to the chain segment n in long-chain alkenyl acetates, CH3(CH2)nCH = CH(CH2)m-O-COCH3 (I), was investigated in pheromone receptors of Noctuidae, Tortricidae, and Cochylidae species. The receptor types studied were maximally responsive to (Z)-7-or (Z)-9-dodecen-1-yl acetate, (Z)-7-, (Z)-9-, or (Z)-11-tetradecen-1-yl acetate, or (Z)-11-hexadecen-1-yl acetate, representing key compounds with n = 1, n = 3, or n = 5 methylene groups.

In terms of the relative stimulus amounts required to elicit equivalent EAG amplitudes, the efficacy of the alkyl-branched derivatives was between 1/1000 to 300 times that of the unbranched chain of the same length and double bond position. The effects of branching were specific to the type of receptor, the length and double bond position of the parent chain, and the kind and position of the alkyl substituent. The most pronounced increase observed occurred with receptors for « = 1 type pheromones, (Z)-9-dodecen-1-yl acetate and (Z) -11-tetradecen-1-yl acetate when an α-methyl group was introduced to elongated derivatives; whereas the greatest decreasing effects were obtained on receptors for the n = 5 type compound, (Z)-7-tetradecen-1-yl acetate. The results show basic differences in structure-response relationships between the Noctuidae vs Tortricidae receptors studied.

Various possible effects of the substituent groups during sensory transduction are considered. The data should contribute to further elucidation of interaction mechanisms of unbranched alkenyl acetate pheromones (I) with insect olfactory receptors.
Calcification of a Native Collagen Membrane
Authors: Wiedner Günther , Wilhelm Günther , Jureit G. , Bojadžijev Z.
Published: August 2018

Calcification, Collagen Membrane, Ca/P Ratio Dependence Spontaneous calcification of a membrane made of native collagen has been investigated. The method permits independent variation of calcium and phosphate concentrations. With increasing phosphate concentration the precipitation of calcium-phosphate on the collogen occurs at a conspicuously lower calcium concentration as with a number of other membranes.