bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stimulierung der Immunreaktivität gegen endogene Retroviren und Schutz gegen Leukämie bei älteren AKR-Mäusen nach Impfung mit Antikörpern gegen Virusoberflächen-Komponenten. Rolle des Antikörpers gegen p15(E) / Stimulation of Immunoreactivity against Endogenous Retroviruses and Protection against Leukem ia of Older AKR Mice by Treatment with Antibodies against Retroviral Surface Components. Role of p15 (E) Antibody
Authors: Schwarz Heinz , Thiel H.-J. , Weinhold Kent J. , Bolognesi Dani P. , Schäfer Werner 
Published: August 2018

Abstract
Antibody against viral gp71 is effective therapeutically for high leukemic AKR mice if injected immediately after birth [1], No corresponding effect could be observed after inoculation later in life when the endogenous virus burden is already high. However, if antibody treatment was supplemented by the injection of pi5(E) antibody, a thera­peutic effect was observed even in older mice first treated at an age of 21/2 months. Those mice produced antibodies against viral surface proteins and appeared to be able to survive longer than control mice. Thus pi5(E) antibody might be able to overcome retroviral associated immuno­deficiency. This therapy may have implications for the treatment of the apparently retroviral induced aquired immunodeficiency syndrome (AIDS) of man.
Alteration of Acylphosphate Formation of Cardiac Sarcoplasmic Reticulum ATPase by Calmodulin-Dependent Phosphorylation
Authors: Pifl Christian , Plank Brigitte , Hellmann Gertrude , Wyskovsky Wolfgang , Suko Josef 
Published: August 2018

The calcium-dependent acylphosphate formed by the calcium transport ATPase of cardiac sarcoplasmic reticulum and the calcium-, calm odulin-dependent phosphoester(s) of sarcoplasmic reticulum fractions formed by a calcium-, calmodulin-dependent membrane-bound protein kinase can be distinguished by removal of calcium and/or magnesium by EDTA or hydroxylamine treatment of the acid denaturated membranes. Both procedures decompose the acylphosphate with little effect on the phosphoester(s).
Calmodulin-dependent phosphorylation (2.44 nmol/mg SR protein) reduces the apparent K(Ca) of the acylphosphate steady state level of the calcium transport ATPase from 0.56 to 0.34 μM free calcium, without affecting the maximum phosphoenzyme level (0.93 versus 0.89 nmol/mg protein), and has little, if any, effect on the Hill-coefficient (1.32 versus 1.54)
Neue Terphenylchinone aus Mycelkulturen von Punctularia atropurpurascens (Basidiomycetes) / New Terphenylquinones from Mycelial Cultures of Punctularia atropurpurascens (Basidiomycetes)
Authors: Anke Heidrun , Casser Ingrid , Herrfnann Rupert , Steglich Wolfgang 
Published: August 2018

Abstract
Three violet terphenylquinone pigments, 4′-hydroxyphlebiarubrone (2), 4′,4″-dihydroxy-phlebiarubrone (3), 3′,4′,4″-trihydroxyphlebiarubrone (4), and the already known pigment phlebiarubrone (1) were isolated from cultures of Punctularia atropurpurascens. The structures of the phlebiarubrone derivatives were determined by spectral evidence. The structure of 3 was confirmed by synthesis from atromentin (6). Two strains of the genus Punctularia obtained from CBS, were also found to produce these compounds, whereas with a third strain only the production of 1 was observed. 3 did not exhibit any antimicrobial or cytotoxic activity. The other pigments showed weak antibacterial and cytotoxic activity.
Tyrosine Oxidation by NO2
• in Aqueous Solution
Authors: Prütz Walter A. 
Published: August 2018

Abstract
Nitrogen dioxide, formed by γ-radiolysis in deaerated aqueous nitrate/nitrite solutions, is capable of oxidizing Gly-Tyr in favourable competition with the natural decay of NO2
• by dimerization and disproportionation. 2,2′-Biphenolic tyrosine dimers and nitro-tyrosine were identified spectroscopically as stable products. The results suggest that NO2
• reacts with the peptide by electron abstraction, generating Gly-Tr phenoxyl radicals (PheO•) which terminate by dimerization (2 PheO• → 2,2′-biphenol) and NO2
• -scavenging (PheO• + NO2
• → Nitro-Tyr).
Comparison of Different Methods for the Determination of Phenylalanine Hydroxylase Activity in Rat Liver and Euglena gracilis
Authors: Fink Rita M. , Elstner Erich F. 
Published: August 2018

Abstract
Three different methods for the determination of phenylalanine hydroxylase activity have been compared:
a) Differential photometric assay of the increase in tyrosine concentration in the presence of phenylalanine;
b) Product separation by thin layer chromatography and scintillation counting of the [14C]tyrosine formed;
c) HPLC separation and spectrofluorometric quantification of derivatized amino acids.
A comparison of the activities of phenylalanine hydroxylase in rat liver and Euglena gracilis clearly showed that only rat liver contains this enzymic activity as shown by methods b) and c) although pseudo-activity of Euglena gracilis preparations was found during the spectrophotometric test a).
The HPLC method proved to be the fastest, most reliable and convenient method for direct tyrosine determination and thus for measuring phenylalanine hydroxylase activity.
On the Reactivity of Native Phytochrome
Authors: Eilfeld Peter , Rüdiger Wolfhart 
Published: August 2018

Abstract
Previous phytochrome models were based on experimental results obtained only with proteolytically degraded phytochrome. The reactivity of native phytochrome, in both the Pr and the Pfr form, towards 8-anilinonaphthalene-1-sulfonate (ANS), urea, and ethylene glycol is described here. Whereas native phytochrome in the Pfr form is only very slowly bleached by ANS, immediate bleaching occurs with ANS treated Pr during red irradiation. The bleached form, Pr660, can be converted into Pr660 by prolonged far-red irradiation. A tentative model for native phytochrome is proposed which explains the effects of phototransformation, ANS binding and partial proteolysis.
Uncoupling of Spinach Thylakoids by Gramine
Authors: Andreo Carlos S. , Orellano Elena G. , Niemeyer Hermann M. 
Published: August 2018

Abstract
The indol alkaloid gramine inhibited photophosphorylation, Pi-ATP exchange reaction and proton gradient, and enhanced electron transport in spinach thylakoids with I 50 around 0.2 mᴍ. It thus behaves as a typical uncoupler of photophosphorylation.
Notizen: Oxidized p-Phenylenediamine Staining of Epoxy Resin Sections
Authors: Stockert J. C. , Armas-Portela R. , Colman O. D. , Ferrer J. M. , Tato A. 
Published: August 2018

Abstract
Semithin and thin sections of glutaraldehyde-fixed, epoxy resin-embedded animal tissues were treated with solutions of oxidized p-phenylenediamine (PPD). This method is suitable to reveal the general morphology of tissues in light microscopy, showing a high staining degree in some polyanion containing components. Posttreatments of thin sections with gold chloride solutions give consider­ able electron opacity in PPD positive structures.
Die Verbreitung des β-Cyan-ʟ-alanin bei cyanogenen Lepidopteren / The Distribution of β-Cyano-ʟ-alanine in Cyanogenic Lepidoptera
Authors: Witthohn K. , Naumann C. M. 
Published: August 2018

Abstract
The toxic amino acid β-cyano-L-alanine is shown to be present in 21 species of the Zygaenidae, which are known to produce and store the cyanoglucosides linamarin and lotaustralin. β-Cyano-alanine is also reported for the first time from other cyanogenic Lepidoptera, i.e. the Acraeinae and the Heliconiinae of the nymphalid family and from other species of the Nymphalidae, which have not been known to be cyanogenic before. Cyanogenesis, including the presence of β-cyano-alanine and the cyanoglucosides linamarin and lotaustralin is demonstrated for the first time for the Heterogynidae.
Purification by Affinity Chromatography of Glutathione Reductase (EC 1.6.4.2) from Escherichia coli and Characterization of such Enzyme
Authors: Mata Anna M. , Carmen M. , López-Barea Juan 
Published: August 2018

Abstract
The glutathione reductase from Escherichia coli strain S33 was purified to homogeneity by a simple and fast procedure consisting of two affinity chromatography steps. After 40-80% ammonium sulfate fractionation, the enzyme was adsorbed to an N6-2′.5′-ADP-Sepharose affinity column from which it was specifically eluted by a 0 - 10 mᴍ NADP+ linear gradient. The enzyme was finally purified to homogeneity after a second affinity chromatography step in a C8-ATPR-Sepharose column, from which it was eluted by means of the same NADP+ gradient. Starting from 182 g of E. coli cells. 6.9 mg of pure enzyme was obtained after a 2632-fold purifi­cation, with a total yield of 63%. The pure enzyme showed a specific activity of 361 U/mg, and its absorption spectrum was characteristic of a flavoprotein. with an A272A450 of 7.84. The enzyme was a dimer with a molecular weight 109 000 and 40 Å hydrodynamic radius. The optimum pH were 7.5 and 4.5 with NADPH and NADH. respectively, as reductants. Apparent K′m values of 16, 377, and 66 μᴍ were determined at pH 7.5 for NADPH, NADH, and GSSG, respectively. Upon storage the enzyme was stable at pH values ranging from 7.5 to 9.5, being additionally stabilized by FAD. NADP+, dithiothreitol, or glycerol. The pure enzyme was quite heat stable, denaturing signifi­cantly only after 10 min at 70 0C. A marked activity loss was observed however, even at 0 °C, in the presence of 20 μᴍ NADPH. The enzyme was inactivated by low concentrations of para- hydroximercuribenzoate: the sensitivity towards such mercurial was greatly enhanced after reduction of the enzyme by NADPH.
Occurrence of Mercaptopyruvate Sulfotransferase Activity in Photosynthetic Organisms
Authors: Schmidt Ahlert 
Published: August 2018

Abstract
Mercaptopyruvate sulfotransferase activity catalyzes the formation of pyruvate from mercaptopyruvate in the presence of suitable reagents as acceptor. It was detected in Lemna minor, Pisum sativum, Spinacia oleracea, Chlorella fusca, Synechococcus 6301, and Rhodopseudomonas palustris. Best activity was detected using dithioerythritol as a thiol reagent; good activity was obtained using mercaptoethanol, glutathione, mercaptopyruvate or sulfite as acceptor. The pH-optimum for the Chlorella mercaptopyruvate sulfotransferase was found around 9; the apparent Km for mercaptopyruvate was determined to 2mᴍ and for dithioerythritol for 5mᴍ using crude Chlorella extracts. The role of this enzyme is discussed in relation to cysteine catabolism by photosynthetic organisms.
Occurrence of the Bacteriochlorophyll-Binding Polypeptides B870α and B800— B850α in the Mutant Strains Y5 and Ala+ of Rhodopseudomonas capsulata, which are Defective in Formation of the Light-Harvesting Complexes B870 and B800 — 850, Respectively
Authors: Tadros Monier H. , Dierstein Roland , Drews Gerhart 
Published: August 2018

Abstract
The mutant strains A l a+ and Y 5 of Rhodopseudomonas capsulata are defective in formation of the light-harvesting complexes B800-850 and B870, respectively, but synthesize the large bacteriochlorophyll-binding polypeptides of the respectively complexes, shown by amino acid composition, N- or C-terminal sequence and immunoblotting. The stable assembly of the light-harvesting complexes in the membrane seems to be dependent from the coordinated synthesis of all pigment and protein components.
Binding of the Fluorescent Dye 8-Anilinonaphthalene 1-Sulfonic Acid to the Native and Pressure Dissociated β2-Dimer of Tryptophan Synthase from Escherichia coli
Authors: Seifert Thomas , Bartholmes Peter , Jaenicke Rainer 
Published: August 2018

Abstract
The β2-dimer of tryptophan synthase from Escherichia coli exhibits weak binding of 8-anilinonaphthalene-1- sulfonic acid (ANS). Titrating the dye at 0.2 mᴍ concen­tration with the apo-β2-dimer at atmospheric pressure causes increased fluorescence emission at 480 nm (λexc = 380 nm), corresponding to unspecific binding of the ligand to hydrophobic residues. Increasing hydrostatic pressure affects ANS binding. Up to 700 bar. a sigmoidal increase of ANS fluorescence reflects an increase in hydrophobic surface area, probably caused by subunit dissociation. At ~ 1 kbar, a maximum is reached; beyond this value, pressure competes with ligand binding causing fluorescence emission to be decreased again. Pressure release leads to a drastic fluorescence enhance­ment, ascribed to ANS binding to the partially and re­versibly denatured enzyme. Plotting the total fluorescence enhancement vs. pressure yields a profile which parallels the pressure dependent dimer ⇆ monomer transition monitored by subunit hybridization (T. Seifert, P. Barthol- mes, and R. Jaenicke, Biochemistry, in press).
Effects of Vitamin D3 on in vivo Labelling of Chick Skeletal Muscle Proteins with [3H]Leucine
Authors: Boland Ana R. de , Boland Ricardo L. 
Published: August 2018

Abstract
The effects of the administration of a single oral dose of vitamin D3 to rachitic chicks on the in vivo incorporation of [3H]leucine to proteins of skeletal muscle subcellular fractions was studied. A significant stimulation (50%) of labelling of mitochondrial proteins could be seen. The sterol affected the labelling of sarcoplasmic reticulum (20%) and contractile proteins (10%) to a lesser extent. These results confirm previous observations which im­plicate vitamin D3 in the synthesis of mitochondrial proteins.
Ein neues Isolierungsverfahren für Schweinenierenacylase. Kinetik des Co2+, Mn2+, Ni2+ und Cd2+-enzyms / A New Isolation Procedure for Acylamino Acid Amidohydrolase. Kinetics of the Co2+, Mn2+, Ni2+ and Cd2+ Enzyme
Authors: Gilles Ingrid , Löffler Hans-Gerd , Schneider Friedhelm 
Published: August 2018

Abstract
A new procedure for the isolation of highly purified acylamino acid amidohydrolase from hog kidney is d e­ scribed which allows the preparation of the enzyme with a recovery of about 45%, a 200 fold purification and a spec.activity of 350-500 U. The essential Zn2+ of the enzyme was exchanged for Co2+, Ni2+, Mn2+ and Cd2+, and the kinetic parameters KM, kcat and kcat/ KM of the different enzyme species for a series of acetyl-L-amino acids were determined.
Control of the Activity of Brain Synaptosome-Associated Acetylcholinesterase by Acidic Phospholipids
Authors: Tsakiris Stylianos 
Published: August 2018

Abstract
Incubation of synaptosomal plasma membranes (SPM) with liposomes of phosphatidylserine (PS), phosphatidylinositol (PIN) or phosphatidylglycerol (PGL), led to an increase of acetylcholinesterase (AchE) activity at concentrations of 0.1-1 μmol phospholip ids per mg SPM protein. The use of higher concentrations (1-7 μmol/mg protein), however, led to a progressive inhibition of the activity with respect to the maximal percentage of enzyme stimulation. To explain the enzyme stimulation by the acidic phospholipids, AchE was solubilized with the detergent Lubrol-PX and showed no change in the enzyme activity at any PS, PIN or PGL concentration used, indicating that these compounds do not act on the protein molecule directly. Arrhenius plots of AchE activities in untreated SPM (control), exhibited a break point at 23 °C , which was decreased to 16-17 °C in PS-treated SPM. Moreover, the Arrhenius activation energy (Ea) value in PS-treated SPM was increased related to the Ea below the break point in the control. These results indicate that acidic phospholipids do not act on AchE directly, but indirectly, affecting the membrane fluidity probably. Such modifications of interactions between lipid and AchE may control physiological processes in the central nervous system .
Fructose-Stimulated Ferrievanide Reduction by Intact Blue-Green Algae
Authors: Scherer Siegfried , Boger Peter 
Published: August 2018

Abstract
As reported in the literature, ferricyanide reduction of blue-green algal cells in the dark is linked to respiratory electron transport. This study has not verified this hypothesis. There was no concurrent activity of ferricyanide reduction by intact cells with respiratory oxygen uptake. It was found light-independent, showing little KCN-inhibition, but was strongly CCCP-sensitive. CCCP inhibition was reversed by KCN. - Both, respiration and ferricyanide reduction were stimulated by fructose which was actively accumulated by the cells (the apparent K m was 20 μM). Ferricyanide reduction was more sensitive towards dark starvation than respiration. Based on these data it is suggested that ferricyanide reduction and cyanide-sensitive respiration are parts of different electron-transport processes, competing for reduction equivalents originating from the same (endogenous) carbon pool.
Cellular Differentiation of Sucrose Metabolism in Anabaena variabilis
Authors: Schilling Norbert , Ehrnsperger Klaus 
Published: August 2018

Abstract
Upon treatment of whole filaments of Anabaena variabilis with a French pressure cell, the activity of sucrose synthase (UDP glucose; D-fructose 2-α-ᴅ-glucosyl transferase, EC 2.4.1.13) was found to be associated almost exclusively with the vegetative cells. The sucrose-cleaving enzyme, an alkaline invertase (β-ᴅ-fructofuranoside fructohydrolase, EC 3.2.1.26), appears to be localized solely within the heterocysts. The implications of these findings, in the light of relevant data from the literature, are summarized in a model representing the physiological differentiation and molecular exchange between vegetative cells and heterocysts.
Tumor Inhibition by Ferricenium Complexes: Systemic Effect in vivo and Cell Growth Inhibition in vitro
Authors: Köpf-Maier Petra 
Published: August 2018

Abstract
The antiproliferative activity of divers ferricenium complexes [Cp2Fe]+X- (X-= [CCl3COO]- · CCl3COOH (I); X- = [CCl3COO]- · 2 CCl3COOH (II); X- = ½ [Cl3FeOFeCl3]2- (III); X- = [FeCl4]- (IV); X = [2 ,4, 6-(NO2)3C6H2O]- (V)) was investigated against solid, subcutaneously growing Ehrlich ascites tumor (EAT) in vivo as well as against EAT cells cultivated in vitro as permanent suspension culture. In vivo, triple intraperitoneal injections of the complexes II (3 × 200 mg/kg), III (3 × 100, 140, 180 mg/kg) or IV (3 × 160 mg/kg) markedly suppressed tumor development thus that the sizes of treated tumors were reduced to 42-48% related to control tumors (100%); these results point to the systemic character of the antitumor action by ferricenium complexes in vivo. In vitro, all ferricenium complexes inhibited cellular proliferation to an equal extent; application of 10-5 ᴍ diminished the increase in cell number by 20-40%, application of 10-4 ᴍ resulted in a total cessation of cellular proliferation. In comparison to cis-diamminedichloroplatinum(II), the cell growth-inhibiting effect of ferricenium complexes was less pronounced and required 10-to 50-fold higher concentration levels to evoke equivalent cytostasis.
Presumed Sex Pheromone from Androconial Glands of Male Cotton Harlequin Bug Tectocoris diophthalmus (Heteroptera; Scutelleridae) Identified as 3,5-Dihydroxy-4-pyrone
Authors: Knight D. W. , Staddon B. W. , Thorne M. J. 
Published: August 2018

Abstract
3,5-Dihydroxy-4-pyrone 3,5-dihydroxy-4-pyrone (Rubiginol) has been identified as a presumed sex pheromone from the cotton harlequin bug Tectocoris diophthalmus (Thunberg). It accumulates as a temporary crystal­ line deposit in the male adult on the external surface of the androconial glands which occur in three pairs on abdominal sternites IV to VI.
Bleomycin-Iron Complex and Oxygen Activate Algal Ribonucleotide Reductase
Authors: Hofmann Rüdiger , Follmann Hartmut 
Published: August 2018

Abstract
Ribonucleotide reductase of green algae (Scenedesmus obliquus) is a radical-containing enzyme which rapidly loses activity under anaerobic conditions. Reactivation in the presence of air is enhanced by 10 μᴍ iron(II)-bleomycin chelate. The reaction lends new biochemical potential to the antibiotic and should be valuable in mechanistic studies of ribonucleotide reduction.
Biochemisch-pharmakologische Untersuchung pflanzlicher Arzneistoffe. II . Hemmung der Acetylcholinesterase durch Monoterpenderivate in vitro / Molecular Pharmacological Investigation of Medicinal Plant Substances. II. Inhibition of Acetylcholinesterase by Monoterpene Derivatives in vitro
Authors: Gracza L. 
Published: August 2018

Abstract
Monoterpene derivatives with spasmolytic activity inhibited acetylcholinesterase (ACHE, EC 3.1.1.7) in a dose dependent manner in vitro. The median inhibitory concentrations ranges between 10-4 ᴍ and 10-2 ᴍ. A significance of our finding may by the possible explanation of effects of monoterpene derivatives seen in distony of digestive tract.
Amin-carbamoyl-10B-boran, Darstellung und biologische Eigenschaften / Amine-carbamoyl-dihydro-10B-borane, Preparation, and Biological Properties
Authors: Dallacker Franz , Böhmel Thomas , Mückter Heinrich 
Published: August 2018

Abstract
The chemical section deals with the synthesis of sodiumcyano-10B-borhydride (3) from 10B-boric acid trimethyl ester (1) via sodium-10B-borhydride (2). By converting 3 with trimethylammonium chloride, trimethylamine-cyano-10B-borane (4) is formed which, via nitrilium tetrafluoroborate 5, is transformed by water to Trimethylamine-carboxy-dihydro-10B-borane (6). Trimethylamine-ethoxycarbonyl-dihydro-10B-borane (8b) and amine-carbamoyl-dihydro-10B-borane (8c) can be synthesized from the imidazolid 8a.
In the biological section an orientation to the toxicity and the tumor affinity of the compounds 6, 7, and 8c are described. Further the possibility is shown by achieving a maximal concentration of 10B-boron in the tumor whilst at the same time retaining as low a concentration of 10B-Boron as possible in the surrounding tissue.
Gewinnung trägerfreier Syntheseprodukte in bestrahltem Valin durch heiße 11C-Atome aus (γ, n)-Kernreaktionen / Carrierfree Synthesis Products from Irradiated Valine by Means of Hot 11C-Atoms of Giant Resonance Reaction
Authors: Gundlach G. , Sattler E. L. , Wagenbach U. 
Published: August 2018

Abstract
The hot 11C-atom derived from (γ, n)-nuclear reaction of the 40 MeV-Bremsstrahlung of a electron linear accelerator may react with valine irradiated. Besides retention-labelling of valine new products which are essentially carrierfree may be produced. By this means leucine has been separated using HPLC and identified by electrophoresis in amounts of 25 MBq labelled com­pound.
Physicochemical Properties of Ferredoxin from Chlamydomonas reinhardii
Authors: Galván Francisco , Márquez Antonio J. , Fernández Emilio 
Published: August 2018

Abstract
Ferredoxin from Chlamydomonas reinhardii has been purified to electrophoretic homogeneity by an easy and fast procedure with a high yield (25 -30 mg/250 g wet weight of cells). An average molecular weight of 11800 was calculated from sedimentation coefficient (1.70 S) and Stokes radius (1.75 nm) data, sodium dodecyl sulfate-electrophoresis, and amino acid composition. Absorption spectrum show ed maxima at 276, 330, 420 and 460 nm in the oxidized form, with an absorption ratio (A420/A276) of 0.54 and an extinction coefficient of 8.38 mᴍ-1· cm -1 at 420 nm. R educed ferredoxin show ed a single peak at 276 nm with shoulders at 284, 310, 390, 469 and 537 nm and at liquid helium temperatures gave EPR signals at g = 1.877, 1.951 and 2.045. The protein has an isoelectric point of 3.30, and one (2Fe-2S)-cluster per molecule with a midpoint potential, at pH 7.5, of -410 mV (n=1) . The m olecule of C. reinhardii ferredoxin consists of 95-99 amino acid residues which includes the full com plement of amino acids, being alanine the most abundant.