bluuebunny/crossref_metadata_2025 huggingface dataset:
Further Observations on in vivo Radioprotection of Rats by Selenourea
Authors: Badiello Roberto , Gattavecchia Enrico , Mattii Mario , Tamba Maurizio
Published: August 2018

This paper deals with a study of some tests in rats in vivo after gamma irradiation in the presence and in the ab­ sence of selenourea. The factors considered were the total protein content, the protein pattern, and some serum enzymes, like GOT, GPT and AP. The result shows that the preadministration of selenourea modifies fovourably the changes induced by ionizing radiation
Effect of imipramine on human chromosomes studied by the method of poly-l-lysine binding
Authors: Marfey S. P. , Li M. G.
Published: August 2018

Metaphase chromosomes of group A isolated from the imipramine-treated lymphocyte cultures did bind more tritiated poly-ʟ-lysine (3H-PL) than the control chromosomes. The increase in binding was dependent on the length of treatment and on contraction of chromosomes. The effect of contraction was more pronounced for the treated chromosomes than for controls and was larger when the treatment was done 4 hours before termination of culture. The observed differences in the 3H-PL binding probably reflect differences in the chromosomal surface morphology
Synthese des Phlebiarubrons und der Polyporsäure / The Syntheses of Phlebiarubrone and Polyporic Acid
Authors: Dallacker Franz , Ditgens Klaus
Published: August 2018

The preparation of phlebiarubrone (1) and polyporic acid (13) starting with 1,2-dimethoxy-4.5-methylenedioxybenzene (3) is described.
Shuttles of Artificial Electron Donors for Photosystem I Across the Thylakoid Membrane
Authors: Hauska G. , Oettmeier W. , Reimer S. , Trebst A.
Published: August 2018

NADP+ reduction in isolated chloroplasts of spinach by photosystem I at the expense of various artificial donor systems is not inhibited by the plastoquinone antagonist dibromothymoquinone. The coupled ATP formation in such photoreductions is attributed to an artificial energy conserving site, i. e. a proton liberation during oxidation of the donor at the inner surface of the thylakoid membrane.

Some donor systems for photosystem I are stimulated by uncouplers whereas others are not. The stimulation shows no correlation to the efficiency of the coupled photophosphorylation. Instead a correlation of the stimulation by uncouplers to the presence of an acidic OH-group in the donor molecule is seen. The uncoupler effect is therefore not explained by a release of electron transport control by the high energy state but rather by a pH-dependent distribution of the donor compound across the membrane. This is supported by the properties of donor systems in sonicated chloroplast particles with external oxidation sites of photosystem I.
Phytochromsystem und Lipochinonsynthese in den Plastiden etiolierter Hordeum-Keimlinge Phytochrome System and Synthesis of Lipoquinones in the Plastids of Etiolated Hordeum Seedlings
Authors: Lichtenthaler Hartmut K. , Kleudgen Hans K.
Published: August 2018

Short pulses of red light induce in etiolated barley seedlings an enhanced synthesis of plastidic benzoquinones and vitamin K1 , which can be reverted by subsequent irradiation with short pulses of far-red. As compared to the dark there is more formation of plastoquinone-9 than α-tocopherol. The enhanced formation of vitamin K1 is coupled with a concomitant decrease in the level of the second naphthoquinone vitamin “K”. The data show that active phytochrome Pfr , also in its ground state, induces the light triggered lipoquinone synthesis which is connected to thylakoid formation. The red light induction of enhanced plastoquinone-9 synthesis cannot be fully reverted by subsequent far-red and seems to be a very fast phytochrome response.
Interactions Between Black Lipid Membranes and the Loosely Bound Proteins from Erythrocyte Membranes
Authors: Brennecke R. , Lossen O. , Schubert D.
Published: August 2018

The loosely bound proteins from hum an erythrocyte membranes induce an up to more than 103-fold increase in the electrical conductivity of black lipid membranes made from oxidized cholesterol. The conductivity increase continues until the membrane breaks. Its magnitude insreases with in­ creasing protein concentration and salt concentration. The results are compared with earlier results obtained with the strongly bound proteins from erythrocyte membranes.
Spontaneous Rearrangement in Langmuir-Blodgett Layers of Tripalmitin Studied by Means of ATR Infrared Spectroscopy and Electron Microscopy
Authors: Kopp F. , Fringeli U. P. , Mühlethaler K. , Günthard Hs. H.
Published: August 2018

1. Under the conditions used in our investigation, tripalmitin layers of the Langmuir Blodgett (LB) type undergo a spontaneous transition, leading from a liquid crystalline (LB) state to a microcrystalline (CR) state.

2. This transition is accompanied by a shift of the methylene bending band from 1469 to 1473 cm-1 and a shift of the ester group motion from about 1169 to 1182 cm-1 . In both cases the half widths of the absorption bands are reduced.

3. The two components of the methylene bending band comprise, within experimental error, all of the tripalmitin present. This is demonstrated by the constancy of the sum of the two band areas attributed to the LB and the CR state respectively. Furthermore, this observation indicates that the liquid crystalline and the crystalline state are the two main types of structural organization occuring in these layers.
The Electroantennographic Detector — a Selective and Sensitive Tool in the Gas Chromatographic Analysis of Insect Pheromones
Authors: Arn Heinrich , Städler Erich , Rauscher Stefan
Published: August 2018

A gas chromatographic detector is described which uses an insect antenna as a sensing element and permits the continuous monitoring of pheromones and other compounds with olfactory activity. In high-resolution gas chromatography allowing separations of positional and geometrical isomers, the electroantennographic detector gives precise information on the retention times of active compounds and permits the analysis of insect pheromones with exceedingly small amounts of material.
Energy-Linked Pyridine Nucleotide Transhydrogenase Activity in Photosynthetically Grown Rhodopseudomonas palustris
Authors: Knobloch Karl
Published: August 2018

Rhodopseudomonas palustris (ATCC 17001) develops energy-dependent NADP+ transhydrogenase activity while growing photosynthetically on thiosulfate, formate, or acetate as the electron donors. The enzymatic activity is present in the supernatant fraction S-.144 000. - As reported, this fraction contains small membrane fragments but no closed vesicles and was shown to drive energy-dependent reversed electron flow as well as an aerobic respiratory electron transport. The energy-dependent transhydrogenase reaction in this fraction can be driven either by ATP, ADP, or inorganic pyrophosphate, but also by acetyl phosphate or acetyl-coenzyme A in the presence of orthophosphate. - Arsenate acts as an inhibitor and decreases preferentially the acetyl-coenzyme A-dependent and the acetyl phosphate-driven reaction; whereas, oligomycin inhibits preferentially the ATP-and the acetyl phosphate-dependent reactions. - Acetate kinase and a phosphotrans-acetylase are operative in S-144 000.
Studies on Fragments of Rod Outer Segments from Bovine Retinas
Authors: Karan Hiroko I. , Brody Seymour S.
Published: August 2018

Vision, Monolayers, Rhodopsin, Photobiology Monolayers of fragments of our rod segments were formed at an air-water interface. The area of these particles was measured as a function of the pH of the aqueous phase. A maximum area was measured at pH 6.5.

The film was characterised by measuring the decrease in surface pressure, after compression, and the half time required to reach constant pressure. At a pH between 6 and 7 the decrease in surface pressure was a minimum.

Irradiation of films of fragments resulted in a decrease in surface potential of between 30 and 40 mV. The largest decrease occured at a pH between 6 and 6.5. A small decrease in surface pressure was also observed upon irradiation.

Mixed films of fragments and phosphatidyl ethanolamine were examined. Irradiation of the mixed film resulted in a 70 mV decrease in surface potential.
UV-Induction of Thymine-Containing Dimers in Saccharomyces cerevisiae
Authors: Fäth W. W. , Brendel M.
Published: August 2018

In haploid and diploid S. cerevisiae the dimer yield ratio TT̂/CT̂ is found to be 1.2/1 and 1.3/1, resp., at the UV (254 nm) unit dose 1 erg/mm2, the share of TT̂ and CT̂ in a UV (254 nm) lethal hit being 0.7 TT̂ and 0.6 CT̂. A general formulation of the UV lethal hit is given and discussed. The TT̂ + CT̂ yields obtained for S. cerevisiae are compared to those reported for other organisms. It is found that there obviously exists a directly proportional linear correlation between genome size and TT̂ + CT̂ yield for the UV dose range well below the stationary levels of the TT̂ and CT̂ formation kinetics.
Biological Dictionary
Authors: Gurel Okan
Published: August 2018

It is proposed that the biological communication is a language process with the basic word structure formed as a hexagonal neighborhood on the α-helix region of protein molecules.
Stress-Induced Changes in Cell Titer of Crayfish Hemolymph
Authors: Hamann Alf
Published: August 2018

Cell titer in peripheral hemolymph of crayfishes rises in less than one hour after administration of stress. The stress may be wounding or handling of the animals.
Phase Shifting Effect of Caffeine in the Circadian Rhythm of Phaseolus coccineus L
Authors: Mayer W. , Scherer I.
Published: August 2018

Caffeine, Circadian Rhythm, Sleep and Wakefulness, Phaseolus coccineus L. 4-hour caffeine pulses (10 mᴍ) offered via the trans­ piration stream advances or delays the phase of the circadian leaf movement rhythm of Phaseolus coccineus as a function of the phase of application. It is hypothesized that the caffeine effect upon sleep and wakefulness in man is partly due to this phase-shifting effect.
Untersuchung einer Resonanz des karzinogenen Benzpyren. Studies on a Resonance of Carcinogenic Benzpyrene
Authors: Böhm P , Popp F
Published: August 2018

The a- and p-states of 3.4-benzpyrene are calculated by use of common param eters and of a param eter set which predicts the quasi-degeneracy of these states.

The quasi-degeneracy will be represented by the breakage of pairing theorem and is to be described as a correlation effect, caused by an asymmetric potential.

An external field represents an external perturbation, introduced by interaction with the bioreceptor. The calculation shows a sensitive dependence of probability amplitudes for different configurations which participate in the quasi-degenerated resonance states. Thereby the dipole moment may quickly be changed so that excitons are produced. The resonance phenomenon may lead to the carcinogenic effect
Zur Berechnung des Stoffumsatzes bei Photoreaktionen
Authors: Mauser Heinz
Published: August 2018

A simple but efficient approxim ation method for the integration of differential equations in photokinetics is described. The method can be used in case of weakly and strongly absorbing solutions as well. The rate laws can be calculated as precisely as wanted. The application of this method is not lim ited to simple photoreactions. The procedure and the formalism are shown for the reactions
The Effect of an Antiserum to Plastocyanin on Various Chloroplast Preparations
Authors: Schmid Georg , Radunz Alfons , Menke Wilhelm
Published: August 2018

A monospecific antiserum to tobacco plastocyanin agglutinates strom a-free sw ellable chloroplasts from wild type tobacco, (Nicotia na tabacum var. John William’s Broadleaf) from the tobacco aurea mutant Su/su2, (Nicotiana tabacum var. Su/su2) from Antirrhinum majus and spinach (Spi-nacia oleracea). In this condition the antiserum inhibits linear photosynthetic electron flow in tobacco and spinach chloroplasts. This inhibition of electron transport as well as the agglutination are not observed if the chloroplasts have been sonicated prior to antiserum addition. This is due to the fact that plastocyanin is removed by ultrasonication. The antiserum stimulates a number of photophosphorylation reactions in tobacco chloroplasts. This stimulation is always larger in the aurea mutant chloroplasts and in chloroplasts from yellow leaf patches of a variegated tobacco mutant (N . tabacum , var. NC95) than in the green type chloroplasts. The stimulation appears to be a consequence of the inhibition of linear electron transport. The antiserum does not affect PMS-mediated cyclic photophosphorylation in tobacco chloroplasts from the wild type whereas the reaction appears stimulated in the tobacco mutant chloroplasts. However, menadione-mediated cyclic photo­ phosphorylation is inhibited upon addition of the antiserum. The same is true for noncyclic photo­ phosphorylation coupled to electron transport in the aerobic system diaminodurene/ascorbate → methylviologen in the presence of N-tetraphenyl-p-phenylenediamine in spinach chloroplasts.

If the lamellar system of Antirrhinum and spinach has lost its swellability neither agglutination nor inhibition of electron transport is observed. However, also in this state antibodies to plasto­ cyanin are specifically adsorbed onto the surface of the thylakoid membrane. This state which is characterized by a morphologically well preserved lamellar system is realized in chloroplast prepa­ rations from Antirrhinum and spinach and is termed stroma-freed, chloroplasts.

In both states of the molecular structure of the thylakoid membrane, plastocyanin is located in the outer surface of the thylakoid. However, it cannot be excluded that functioning plastocyanin is also located in the interior of the thylakoid membrane.
The Biosynthesis of 4-Methylsulfinyl-3-butenylglucosinolate (Glucoraphenin) in Matthiola Species / Evidence for Homomethionine and 2-Amino-6-methylthiocaproic Acid as Intermediates
Authors: Löffelhardt W. , Kindi H.
Published: August 2018

[35S] L-Methionine and [methyl-14C] ʟ-methionine were fed to shoots of Matthiola annua and Matthiola sinuata. The label from both precursors was incorporated to a high degree into 4-methylsulfinyl- 3-butenylglucosinolate, the main mustard oil glucoside of M atth iola species. Two homologues of methionine, homomethionine and 2-amino-6-methylthiocaproic acid, were also labelled in these experiments. 2-Amino-6-methylthiocaproic acid, deriving from methionine via homomethionine by two successive C1-chain elongation steps, was higher plants
A Model of Pheromone Molecule-Acceptor Interaction
Authors: Kafka Wolf A. , Neuwirth Jürgen
Published: August 2018

Multiple binding interactions between odor molecules and acceptors are formulated by means of the Boltzmann statistics and intermolecular bond energies. Number, spatial arrangement and electronic properties of binding positions of the acceptor can be defined such that the specificity of sex pheromone receptors in male noctuid moths is quantitatively described.
Synthese von DNA im Gammapflänzchen von Weizen / DNA-synthesis in Gamma-plantlets of Wheat
Authors: Kern Hartmut , Kern Hartmut
Published: August 2018

Wheat, DNA-synthesis, Irradiation Plants, arising from irradiated (300 kR) caryopses of wheat, exhibit a low incorporation of [3H] thymidine into the DNA, which, as shown by sedimentation on sucrose gradients, does not indicate tendencies of normalization.
Isolation and Characterization of Ribosomal RNA from the Phycomycete Allomyces arbuscula / Isolation and Characterization of Ribosomal RNA from the Phycomycete Allomyces arbuscula
Authors: Fähnrich P. , Rothe H.H. , Trapp M.
Published: August 2018

The ribosomal RNA of the gametophyte of Allomyces arbuscula contains two components with sedimentation coefficients of approximately 25S and 18S. The percent base composition of 25S rRNA is 31/28/24/17 (U/G/A/C), that of 18S rRNA 34/28/22/16
Effect of Alkali Chlorides on Human Chromosomes Studied by the Method of Poly-L-lysine Binding
Authors: Marfey S. P. , Li M. G.
Published: August 2018

Human metaphase chromosomes A1 and A3 did bind more tritiated poly-L-lysine ([3H]PL) when they were isolated from lymphocyte cultures treated with LiCl rather than with NaCl or KCl. A2 chromosome did not show this differential behavior and in all three cases did bind more [3H] PL than the control A2 chromosome. The effect was dependent on the time of exposure of cells to the salts in tissue culture and on the degree of chromosomal contraction. The observed differences in [3H] PL binding are probably due to differences in surface morphology of the three chromosomes caused by treatment with alkali metal salts
On the Constituents of the Wild Egyptian Plant Onopordon alexandrinum Boiss
Authors: Wassel G. M.
Published: August 2018

The study of the nitrogenous bases of Onopordon alexandrinum Boiss. resulted on the isolation of stachydrine and choline. The flavonoid components detected are: Luteolin-7-monoglucoside, apigenin-7-glucoside and quercetin.
Propionate as a Precursor of Juvenile Hormone in the Cecropia Moth
Authors: Rodé-Gowal Heike , Abbott Scott , Meyer Dietrich , Röller Herbert , Dahm Karl H.
Published: August 2018

Juvenile Hormone, Biosynthesis, Cecropia Moth Adult 3-4 day old males of the giant silk moth H yalophora cecropia incorporate the label of [1-14C] propionate and [1-14C]butyrate in JH-I and JH-II. [1-14C]propionate is used for the bio­ synthesis of the hormones as an intact C3-unit. Three possible intermediates in the biosynthesis of JH-I-(E,E,Z)-7-ethyl-3,11-dimethyl-2,6,10-tridecatrienoic acid, its methyl ester, and the cor­ responding alcohol - were converted in low yields to the hormone. Methyl 7-ethyl-3,11-dimethyl-tridecanoate was not incorporated. Mevalonate applied to larvae before pupation was not used for the synthesis of a hypothetical JH-I precursor.
In vitroTranslation of Natural mRNAs in a Cell-free System Containing Components from Interferon-treated Chicken Fibroblasts and Factor Preparations from Mouse Ascites Cells or Rabbit Reticulocytes
Authors: Hiller G. , Viehhauser G. , Winkler I. , Pohl D. , Jungwirth C. , Bodo G.
Published: August 2018

Interferon Mechanism, in vitro Translation, Viral and Cellular mRNA, Chick Embryo Fibroblasts, Vaccinia Infection The effect of interferon has been studied in a mixed cell-free protein synthesizing system. Hemo­ globin (Hb) and Encephalomyocarditis virus (EMC) -RNA can be efficiently translated in vitro in a system containing S-30 lysates or run-off ribosomes from primary chick embryo fibroblasts (CEF) and a postmicrosomal supernatant from mouse ascites cells or a ribosomal-wash preparation from rabbit reticulocytes. Ribosomes prepared from CEF pretreated with high doses of homologous inter­ feron (500 units/ml) were able to translate Hb-RNA in the presence of heterologous factors with the same efficiency as ribosomes prepared from control cells. Translation of EMC-RNA was slightly reduced if ribosomes from interferon-treated cells were used in the mixed cell-free system, confirming previous reports. No inhibitory effect caused by interferon treatment of CEF cells could be detected on in vitro translation of natural mRNAs if the cells had, in addition to interferon treatment, been infected with vaccinia virus. Possible reasons for the different observations made with our cell-free protein synthesizing system from CEF and with cell-free systems prepared from mouse cells are discussed.
Activation and Inhibition of the Mg-Ca-ATPase from E. coli by Mg2+ and Ca2+
Authors: Ahlers Jan , Günther Theodor
Published: August 2018

Mg-Ca-ATPase, E. coli, Activation, Inhibition MgATP or CaATP is the substrate of the Mg-Ca-ATPase. At low Mg2+-or Ca2+-concentrations the ATPase is activated by Mg2+ or Ca2+, the activator being essential for activity. At higher Mg2+-or Ca2+-concentrations the Mg-Ca-ATPase is inhibited competitively. Thus the real Km is smaller than reported in the literature. H+ competes with Mg2+ or Ca2+ for the metal binding sites.
On the Phospholipase Activity in Bovine Seminal Vesicles and Its Possible Role in the Regulation of the Prostaglandin Biosynthesis
Authors: Luckner Gabriele , Renz Paul
Published: August 2018

A phospholipid mixture was isolated from bovine seminal vesicle tissue. This phospholipid preparation contained the following prostaglandin precursor fatty acids: 4.7 percent 5,8,11-eicosatrienoic acid, 9.1 percent 5,8,11,14-eicosatetraenoic acid and 0.9 percent 5,8,11,14,17-eicosapentaenoic acid.

With this phospholipid preparation as substrate phospholipase activity could be detected in different fractions of bovine seminal vesicle cells. The highest phospholipase activity was found in the microsomal fraction, less in the mitochondria and essentially no activity in the cytosol.

With a microsome preparation (acetone powder) of bovine seminal vesicles the influence of certain effectors on the phospholipase activity was investigated. Prostaglandins E2 and F2a (10-5 м) showed 19 and 41 percent inhibition, DB-c-AMP (2 × 10-9 м) 54 percent, c-AMP (10-9 м) 22 percent, epinephrine (10-4 м) 60 percent, testosterone (10-5 м) 25 percent inhibition of the phos­pholipase activity.

Whereas ethanol exhibits also a strong inhibition on the phospholipase activity, it shows a pronounced activation of the prostaglandin synthetase.
Wirkungsmechanismus und Struktur-Aktivitätsbeziehungen des Aminotriazinon-Herbizids Metribuzin. Hemmung des photosynthetischen Elektronentransports von Chloroplasten durch Metribuzin / Mode of Action and Structure-Acitivity-Relationships of the Aminotriazinone Herbicide Metribuzin. Inhibition of Photosynthetic Electron Transport in 'Chloroplasts by Metribuzin
Authors: Trebst A. , Wietoska H.
Published: August 2018

The influence of the aminotriazinone herbicide Metribuzin on photosynthetic reactions of isolated chloroplasts is investigated. Metribuzin inhibits all Hill-reactions when water is the electron donor, but not photoreductions by photosystem I at the expense of an artificial electron donor. The PI50-value is 6.7. Cyclic photophosphorylation is not affected by Metribuzin. Measurements of the prompt and delayed fluorescence of the photosynthetically active chlorophyll support the notion, that Metribuzin inhibits photosynthetic electron flow between the primary and secondary electron acceptor of photosystem II (Q and plastoquinone).

The relationship of inhibitory potency to chemical structure is investigated by comparing a number of related aminotriazinones. The effect of various substituents is discussed.
Conductance Characteristics of Interactive Subunit Membranes
Authors: Bretag A. H. , Kerr D. I. B.
Published: August 2018

Membrane channels formed by groups of subunits with a special form of interaction between the subunits provide a simple basis for models of membrane conductance. It is shown how the subunit interaction can explain conductance kinetics; particular attention being paid to characteristics of the potassium conductance in the squid piant axon.
Bildung von Naringenin bei der Reife von Tomaten / Formation of Naringenin in Ripening Tomatoes
Authors: Schmidtlein Helmut , Herrmann Karl
Published: August 2018

Naringenin (5,7,4′-trihydroxy-flavanon), occuring only in the skin of tomatoes, is formed when the fruit begins to colour red.
Reactions of Essential Sulfhydryl Residues of Dehydrogenases with Nicotinamide-(S-Methylmercury-Thioinosine) Dinucleotide
Authors: Woenckhaus Christoph , Duchmann Helmut
Published: August 2018

Sulfhydryl Groups, Methylmercury Containing Inactivator, Coenzyme Analogue Nicotinamide-(S-methylmercury-thioinosine) dinucleotide was formed by reaction of nicotin­ amide-(6-thiopurine) dinucleotide with methylmercury chloride. The compound exhibits coenzyme properties in the test with LDH (Km=1.5 × 10-4 м , Vmax=12500) and LADH (Km=1.7 × 10-4 м, Vmax=27) and inactivates YADH and GAPDH. From incubations with LDH and LADH the mercury containing coenzyme could be regained by column chromatography. The compound seems to be qualified for the X-ray structure analysis of the coenzyme-enzyme complex for some dehyrogenases based on the proportion of the heavy metal.
Studies on the Structure of β-Chitin, I
Authors: Pervaiz S. M. , Haleem M. Abdul
Published: August 2018

The structure of β-chitin has been studied in detail. Atomic coordinates in the unit cell are determined. Various positions of O6 atom have been studied in detail in order to reduce X-ray discrepancies. It is f duonthat O6 atom lies near 140°.
Calcium Sensitivity of Actomyosin ATPase: Its Modification by Substitution of Myosin Sulfhydryl Groups
Authors: Dancker Peter
Published: August 2018

Actomyosin ATPase, Calcium Sensitivity, Sulfhydryl Groups SH group substitution by DTNB enabled natural actomyosin to split ATP (in the presence of Mg2+) also in the absence of Ca2+, when assayed at low ionic strength. At higher KCl concentrations the ATPase activity of SH group substituted actomyosin was still Ca-dependent. Addition of unsubstituted myosin to natural actomyosin whose SH groups had been substituted increased the ATPase activity. This increase was Ca-insensitive indicating that SH group substitution of myosin in actomyosin can make the interaction of additional myosin molecules Ca-independent. In natural actomyosin Ca-insensitivity of ATPase activity was attained at a lower degree of SH group substitution when substitution was performed in the presence of EDTA. The part of ATPase activity which still remained Ca-sensitive after DTNB treatment could be activated by lower concentrations of free Ca2+ than the Ca-sensitive ATPase of untreated actomyosin. In reconstituted actomyosin the Ca-sensitivity of ATPase activity could more easily be reduced when the myosin-actin ratio was high. For demonstrating remaining Ca-sensitivity in SH group substituted reconstituted actomyosin more tropomyosin-troponin was needed than for sensitizing unsubstituted actomyosin to Ca2+. - The similarities between the ATPase activity of SH group substituted actomyosin on the one hand and that of actomyosin at low concentrations of ATP on the other hand suggest that SH group substitution modifies actin-myosin interaction in a similar way as does nucleotide-free myosin (rigor myosin).
The Effect of Antibodies to Neoxanthin on Electron Transport on the Oxygen Evolving Side of Photosystem II and the Reactions of this Antiserum with Various Chloroplast Preparations
Authors: Radunz Alfons , Schmid Georg H.
Published: August 2018

Antibodies to neoxanthin agglutinate stroma-free swellable chloroplasts from tobacco (Nico-tiana tabacum var. John William’s Broadleaf) and Antirrhinum (Antirrhinum majus) whereas stroma-freed chloroplasts, which have lost the swellability are not agglutinated despite the fact that antibodies to neoxanthin are specifically adsorbed. In this latter case the agglutination is hindered for sterical reasons. From this it is concluded that neoxanthin is located in the outer surface of the thylakoid membrane. The antiserum to neoxanthin inhibits the ferricyanide photo­ reduction in chloroplasts when water is the electron donor by 15%. With diphenylcarbazide in tris-treated chloroplasts no inhibition is observed. Hence, just as in the case of the antiserum to lutein the site of inhibition is on the donor side of potosystem II namely between water and the site of electron donation of diphenylcarbazide. Benzidine/ascorbate is another artificial electron donor system of photosystem II reported in the literature. The photoreduction of anthraquinone-2-sulphonate with this donor system is inhibited. In contrast to the antiserum to lutein the antiserum to neoxanthin inhibits DCMU-sensitive photophosphorylation reactions in the system H2O → ferricyanide and benzidine/ascorbate → anthraquinone-2-sulphonate. Therefore, the electron transport coupled to photophosphorylation is inhibited by the antiserum.
Cholesterol and Phospholipid Content of 3T3 Cells and Transformed Derivatives
Authors: Adam Gerold , Alpes Heinz , Blaser Käthi , Neubert Brigitte
Published: August 2018

For 3T3, PY-3T3 and SV40-3T3 cells, the contents of total lipid, cholesterol and phospholipid were determined. Weight of total lipid per cell correlates closely with cellular volume as deter­ mined microscopically. This correlation is not observed for cholesterol or phospholipid content per cell.

Cholesterol content per cm2 cellular surface area is found about fifty percent higher in the transformed cell lines compared to 3T3 cells. This result is discussed in relation to thermal transitions observed in physical properties of the plasma membrane of these cells as well as in lamellar phospholipid/water model systems containing cholesterol.
Arrangement of Proteins and Lipids in the Sarcoplasmic Membrane
Authors: Hasselbach Wilhelm , Migala Andrea
Published: August 2018

The number of amino residues present in the proteins of the sarcoplasmic reticulum which can react with Fluram has been determined in native and sonicated SR vesicles. Sonication increases the number of amino groups accessible to Fluram from 0.57 to 0 .8 7 μmol·mg prot.-1. This increase indicates that 66% of the amino residues are present in the external and 34% in the internal membrane leaflet. The distribution of the amino phospholipids is computed from the distribution of Fluram in the membrane proteins in con­junction with the relative distribution of Fluram between protein and lipid in native and sonicated vesicles. The distribution of the calcium transport protein has been approximated under different assumptions concerning the distribution of the residual protein and taking into account that 15% of the membranes of the SR vesicles might have changed their sideness during preparation.
Studies on Phenylpyruvic Acid
Authors: Tautomerism  , Sciacovelli O , Dell 'atti A , De Giglio A , Cassidei L , Tautomerism I. Keto-Enol
Published: August 2018

The tautomerism of phenylpyruvic acid (PPA) and its sodium salt was investigated. The 1H and 13C spectra of PPA in aprotic solvents and in methanol show almost complete prevalence of the enol form, whereas the keto form prevails only in water. The Z configuration was assigned to the sole enol tautomer present on the basis of the value of the vicinal coupling constant | 3J1H,13COOH |=3.7 Hz. A small amount of the hydrated form of PPA (1-phenyl-2,2-dihydroxyl- propanoic acid) was found in the aqueous solution of its sodium salt and in buffer solution (pD =6) of PPA.

By means of infrared spectroscopy one can conclude that crystalline PPA is in the enol whereas its sodium salt is in the keto form. The keto-acid was not obtained in the solid state. The colori­metric method for testing PPA traces in urine depends on the formation of a enol-Fe3+ complex (2:1) which appears stable in dimethylsulfoxide (DMSO).
Studies on Mammalian Pheromones, I. Ketones from the Pedal Gland of the Bontebok ( Damaliscus dorcas dorcas)
Authors: Burger B. V. , Roux Maritha le , Garbers C. F. , Spies H. S. C. , Bigalke R. G. , Pachler K. G. R. , Wessels P. L. , Christ V. , Maurer K. H.
Published: August 2018

The significance of pheromones in olfactory communication in mammals, and the possibility of using synthetic pheromones to influence the behaviour of problem animals, are briefly discussed. The isolation, identification and synthesis of the principal volatile component contained in the pedal gland exudate of the bontebok, Damaliscus dorcas dorcas, viz. (Z)-5-undecen-2-one, are reported. Some of the other major constituents of the secretion have been identified as 2-heptanone, 2 -nonanone, 2 -undecanone and 2,5-undecanedione.
On the Mechanism of the Acridine Orange Sensitized Photodynamic Inactivation of Lysozyme
Authors: Rosenkranz Peter , Kinetics I. Basic , Schmidt Hartmut
Published: August 2018

The kinetics of the photodynamic desactivation of lysozyme in presence of acridine orange as the sensitizer have been investigated in detail varying oxygen, protein, dye concentration, ionic strength and pH value. The kinetics can be approximately described as an over all pseudo-first- order rate process. Changing the solvent from water to D2O or by quenching experiments in pres­ence of azide ions it could be shown that the desactivation of lysozyme is caused exclusively by singlet oxygen. The excited oxygen occurs via the triplet state of the dye with a rate constant considerably lower than that to be expected for a diffusionally controlled reaction. Singlet oxygen reacts chemically (desactivation, k=2.9 × 107 ᴍ-1 sec-1) and physically (quenching process, k = 4.1 × 108 ᴍ-1sec-1) with the enzyme. The kinetical analysis shows that additional chemical reactions between singlet oxygen and lysozyme would have only little influence on the kinetics of the desactivation as long as their products would be enzymatically active and their kinetical constants would be less than about 1 × 108 ᴍ-1 sec-1.
Herkunftsbestimmung von Arzneimitteln durch Messung von natürlichen Isotopenverhältnissen: D/H und 13C/12C Verhältnisse einiger Proben von Diazepam / Determination of the Origin of Drugs by Measuring Natural Isotope Contents: D/H and 13C/12C Ratios of Some Diazepam Samples
Authors: Bommer Peter , Moser Heribert , Stichler Willibald , Trimborn Peter , Vetter Walter
Published: August 2018

The precise determination of the natural isotopic abundance ratios of carbon and hydrogen in several production batches of the commercial product 7-chlor-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-on (diazepam) gave results which allowed certain batches to be differentiated.

The differences in the ratios appear to be mainly due to differences in the isotopic composition of the (fossile) starting materials of the synthesis.

The measurement of the natural isotopic ratios may therefore offer another possibility to deter­ mine the origin of a drug.
Metabolic Products of Microorganisms, 151. Comparative Studies on Intracellular Potassium- and Sodium Concentrations of Wild-Type and a Macrotetrolide Negative Mutant of Streptomyces griseus
Authors: Kanne R. , Zähner H.
Published: August 2018

The studied macrotetrolide negative mutant of Streptomyces griseus showed a different specificity of potassium accumulation than the macrotetrolide producing wild-type, indicating, that the macrotetrolides may be part of the physiological potassium carrier.
Loading of Human Red Blood Cells with DNA and RNA
Authors: Auer Dieter , Brandner Gerhard
Published: August 2018

Human erythrocytes were suspended in Hank’s solution containing mammalian or viral DNA or RNA. After dialysis at 0 °C first against water and subsequently against Hank’s solution, and a further incubation at 37 °C , the erythrocytes were found to be loaded with the nucleic acids.

The nucleic acid trapped in the erythrocytes exhibited up to 35 per cent of the external concentration.
Artificial Energy Conservation in Bacterial Photosynthetic Electron Transport
Authors: Trebst Achim
Published: August 2018

In photosynthesis of chloroplasts and bacterial chromatophores an induced artificial electron flow bypass may restore the inhibition of electron flow and of coupled ATP formation by two possible mechanisms. An artificial transmembrane electron flow bypass will lead to artificial energy conservation, when the redox reaction cycle of the added mediator across the membrane acts as proton pump. In an artificial internal electron flow bypass an inhibited native energy conservation may be reactivated; here an electron flow bypass induced by the mediator in the inside space restores the native proton translocation. The inhibition and the restoration of electron flow by antimycin, dibromothymoquinone and valinomycin is compared.
Notizen: Contribution of Monofunctional Adducts formed by Furocoum arins with DNA to the Inhibition of Nucleic Acids Synthesis
Authors: Baccichetti F. , Bordin F. , Marciani S. , Dall’Acqua F. , Rodighiero G.
Published: August 2018

In addition to the bifunctional adducts (cross-linkages), that furocoumarins on radiation at 365 nm form in DNA, monofunctional adducts also proved able to inhibit the nucleic acid synthesis in Ehrlich ascites tumor cells.
Protonenübertragungsreaktionen zweibasischer Säuren in wäßriger Lösung: 3-Hydroxypyridin / Proton Transfer Reactions of Dibasic Acids in Aqueous Solution: 3-Hydroxypyridine
Authors: Schuster P. , Tortschanoff K. , Winkler H.
Published: August 2018

Proton transfer in aqueous solutions of 3-hydroxypyridin (3HP) has been studied by tempera­ture jump relaxation and ultrasound absorption techniques. Two chemical relaxations have been observed. In the range pK1<pH<pK2 the slower of the two processes corresponds to proton transfer between the N and O atoms. A mechanism is proposed which describes the pH and con­centration dependence of the relaxation time measured. Proton transfer involves two types of pro­cesses which operate in parallel: I. pseudomonomolecular, by consecutive diffusion-controlled protonation and deprotonation steps, and 2. bimolecular by diffusion-controlled proton transfer between the neutral 3HP molecule and its corresponding cation or anion. There is no evidence for direct monomolecular proton transfer within the hydration shell of the molecule (k→ ~ k← < 2 × 1O3 sec-1).
Physiological Effects of Sucrose Substitutes and Artificial Sweeteners on Growth Pattern and Acid Production of Glucose-Grown Streptococcus mutans Strains in vitro
Authors: Linke Harald A. B. , Chang Catherine A.
Published: August 2018

The synergistic effects of four sucrose substitutes, polysorbate and five artificial sweeteners were studied in vitro on growth pattern and acid production of seven glucose-grown Streptococcus mutans strains, representing the five serological groups after Bratthall. Four distinct growth pat­ terns during glucose fermentation were observed: high rate of growth with low acid production, moderate growth rate with moderate acid production, moderate growth rate with high acid pro­duction, and slow rate of growth with moderate acid production. Depending on the strain used, the final OD at 546 nm ranged from 0.55 to 0.99 and the final pH of the medium varied between 4.65 and 4.15. While added sucrose substitutes, with exceptions, usually enhanced growth rate, most artificial sweeteners suppressed or, at higher concentrations, even inhibited growth of S. mutans-, addition of polysorbate to the medium always increased growth rate of S. mutans significantly. The presence of sucrose substitutes during glucose fermentation had no effect on final pH of the medium, but addition of artificial sweeteners, especially sodium saccharin, elevated final pH up to 1.8 units. The observed physiological patterns and differences within the several strains of S. mutans during glucose fermentation in vitro do not necessarily relate to the five serological groups of the species.
Polymergebundenes N-(Hexyl)-5-azido-2-nitro-benzoesäureamid; ein photoreaktiver Träger zur Immobilisierung von Liganden Polymer Linked N-(Hexyl)-5-azido-2-nitro-benzoic Acid Amide; a Photoreactive Resin for the Immobilization of Ligands
Authors: Seela Frank , Hansske Fritz
Published: August 2018

The preparation of a new photochemically-activatable polymer was accomplished by condensation of aminohexyl-6-yl-agarose with the N-hydroxysuccinimide ester of 5-azido-2-nitro-benzoic acid. The latter compound was obtained by diazotization of 5-amino-2-nitro-benzoic acid, exchange of the diazonium group through azide and condensation with N-hydroxysuccinimide. As shown for the photolysis on the monomer level, irradiation of the polymer led to the intermediate formation of a highly reactive nitrene, which is able to immobilize ligands e. g. ʟ-phenylalanine to the polymer.
Wachstums-"burst" nach Anaerobiose: ein "stored grow th"-Effekt beim Streckungswachstum von Koleoptilen / Growth Burst after Anaerobiosis: a " Stored-Growth" Effect in Avena Coleoptiles
Authors: Krauß A. , Hager A.
Published: August 2018

Extension growth of 1-cm segments of Avena coleoptiles (studied in liquid medium by means of a flow chamber) was anomalously increased after short anaerobic treatment. The normal growth rate in air-saturated medium without indole-3-acetic acid (IAA) was about 5 µm/min; the rate decreased under anaerobiosis to about 1 µm/min, followed by an increase up to 30 µm/min when aerobic conditions were restored. This “growth burst” continued for about 10 min; then the rate decreased to the initial value of 5 /tm/min. In the same segment growth enhancement could be induced repeatedly by anaerobic treatments. The phenomenon of growth burst after anaerobiosis may be named “anaerobiosis-aerobiosis-transition effect” (ANA-effect).

The ANA-effect was also observed under conditions of acid-induced growth at pH 4. Further­ more it appeared in coleoptile segments whose growth rate had already been enhanced by IA A .

Anaerobic pre-treatment not only stimulated extension growth but when applied before IAA addition also overcame the lag phase of IAA-induced growth enhancement.

It is supposed that a compound essential for coleoptile growth is accumulated during anaero biosis; such compound together with oxygen may cause the observed growth burst. Possible candidates for this compound are discussed.
Notizen: Synthesis and Electron Spin Resonance Study of Spin-Labelled Compounds Related to Tumour- Growth Inhibitory Nitroarylaziridines
Authors: Dodd N. , Harcus R. , Preston P.
Published: August 2018

Three stable free radicals have been prepared which are akin to 5-aziridino-2,4-dinitrobenzamide (CB 1954) ; these compounds all contain a nitroxide function. The metabolism and excretion of two such compounds in mice has been monitored by electron spin resonance (ESR) spectroscopy and compared with that of the simpler nitioxide, 4-keto-2,2,6,6-tetramethylpiperidino-1-oxyl (tempone).
Der Verteilungsraum von physikalisch gelöstem Sauerstoff in wäßrigen Lösungen organischer Substanzen / The Distribution Space of Physically Dissolved Oxygen in Aqueous Solutions of Organic Substances
Authors: Zander Rolf
Published: August 2018

In order to evaluate the distribution of molecular oxygen in biological systems, the oxygen solubility (ml/ml atm) at 37 °C in aqueous solutions of thirty organic substances with different concentrations was measured by the classical Van Slyke principle.

The oxygen solubility always (with the exception of hemoglobin) decreases exponentially with increasing concentration of the respective substance. In all cases this behavior is described highly significant by a simple empiric exponential function, when the substance concentration as well as the oxygen solubility of pure water is given. The influence of one substance on oxygen solubility contributes additively to the over-all solubility value of a solution of several dissolved substances.

Changes in oxygen solubility and, therefore, oxygen distribution in aqueous solutions may be related to three main phenomena:

1. restriction of the free water volume by the specific partial volume of a dissolved substance (e. g. urea solutions),

2. existence of non-solvent water for oxygen (especially in solutions of amino acids),

3. adsorption of oxygen at the interphase in a heterogenous system (e. g. protein solutions).
X -Ray Diffraction Studies on the Structure of α-Chitin
Authors: Haleem M. Abdul , Parker K. D.
Published: August 2018

The structure for α-chitin originally proposed by Carlström is generally considered to be the true structure. However, it fails to account for several remaining problems of chitin structure which include a complete explanation of the infrared spectrum and also the different properties of a-and β-chitins. W e have reexamined the structure by X-ray diffraction using automatic rigid subunit least-squares refinement and also the difference Fourier method. The R-value was reduced from 0.31 to 0.22 by a number of small modifications to the structure proposed by Carlström. Conside­ration of symmetry suggests that two distinct types of statistical modifications could be present in the structure, both of which would allow complete intersheet hydrogen bonding between O6H groups within the general framework of Carlström structure. The X-ray results give some support to one of these modifications. However, it is predictable that both would affect the X-ray diffraction only marginally so that a clear proof lies beyond the present sensitivity of the method. The proposed extra hydrogen bonding in a-chitin provides the first clear explanation for the different properties of these kinds of chitin.
Purification and Properties of Potato Phosphorylase Isozymes
Authors: Shivaram Kirumakki N.
Published: August 2018

Two multiple forms of α-glucan phosphorylase which migrate about half way in polyacryl-amide-gel electrophoresis (named “slow“ and “fast” isozyme), were isolated by combined chromatography and preparative electrophoresis after freezing the tissue from freshly harvested and from sprouting potato tubers respectively. Depending on the primer used for the synthesis reaction their pH optimum varied between 5.2 and 6.0 and the optimum temperature was 30 and 35 °C. The isoelectric point for the slow isozyme was at pH 5.0±0.1 and for the fast isozyme, pH 5.5±0.1, the molecular weights were 209 000±10 000 and 165 000±5000 and for their subunits 104 000±4000 and 40 000±2000 respectively. Both isozymes were inhibited by Hg2+, Ag+ and p-chloromercuro-benzoate (p-CMB). Fe2+ ions inhibited them partially. Mg2+, Mn2+ and sulfhydryl compounds activated both.

Km values for the slow and fast isozymes with glucose-l-phosphate in presence of soluble starch was 6.7 and 8.0 mM, of amylose 14.3 and 20.0 mм and of glycogen 22.2 and 40.0 mм respectively. The affinity of the primer for the slow and the fast isozymes were as follows: soluble starch 0.5 and 1.0 mм, amylose 2.6 and 3.8 mм, glycogen 6.2 and 7.7 mм respectively. Km values of phosphorolysis with soluble starch was 0.8 and 0.5 mм, with amylose was 3.1 and 1.1 mм, and with glycogen was 6.5 and 1.3 mм respectively. As substrate and primer the soluble starch was superior and the glycogen was inferior. Amylose was in between.

Kinetic parameters suggested the existence of α-glucan phosphorylase isozymes with different specificities: the slow one being more active in the direction of starch synthesis and the fast isozyme degrading faster the polyglucans. These observations suggest that the polyglucan synthesis and degradation in potato tubers may be regulated by the change in the proportion of slow and fast isozymes.
Intermolecular Interactions of Polypeptides and Lipids in the Thylakoid Membrane
Authors: Menke Wilhelm , Radunz Alfons , Schmid Georg H. , Friederike Koenig , Hirtz Rolf-Dieter
Published: August 2018

Intermolecular interactions between chloroplast lipids and a polypeptide fraction from thylakoids were investigated by far ultraviolet circular dichroism. The polypeptide fraction was isolated from dodecyl sulfate-containing buffers. It exhibits an average molecular weight of 24 000. The circular dichroism of this polypeptide fraction measured as mean residue ellipticity is greater in the presence of sodium dodecyl sulfate than in the absence of this detergent. This effect is reversible. Addition of sulfoquinovosyl diglyceride to the dodecyl sulfate-free solution of the polypeptide also causes an increase of the circular dichroism. This increase was only observed in the pH-range between 6.9 and 7.4. The effect of dodecyl sulfate or sulfolipid on the circular dichroism is interpreted to indicate an increase of α-helix content. Monogalactosyl diglyceride, digalactosyl di­glyceride and phosphatidyl glycerol gave no reaction. The attempt to obtain a conformational analysis of the polypeptide in the different states did not yield an entirely satisfactory result. Antisera to sulfolipid inhibit photosynthetic electron transport of stroma-freed chloroplasts in the region of light reaction I. This inhibition is restricted to the same pH-range as the non-covalent binding of sulfolipid to the polypeptides. It appears that in the cell membrane-bound metabolic processes are regulated by this pH-dependence of the sulfolipid-polypetide interactions.