bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dependence on Membrane Lipids of the Effect of Vanadate on Calcium and ATP Binding to Sarcoplasmic Reticulum ATPase
Authors: Medda Pankaj , Hasselbach Wilhelm 
Published: August 2018

Abstract
The affinity of the sarcoplasmic reticulum transport ATPase for calcium and ATP is not affected by lipid depriviation while vanadate binding is completely abolished. Lipid substitution restores vanadate binding as well as the vanadate induced disappearance of the enzyme’s high affinity calcium and nucleotide binding sites. Nucleotide binding is simultaneously restored with the displacement of vanadate from the enzyme following the occupation of its low affinity calcium binding sites.
Titer of Juvenile Hormone III in Drosophila hydei during Metamorphosis Determined by GC-MS-MIS
Authors: Bührlen U. , Emmerich H. , Rembold H. 
Published: August 2018

Abstract
The titer of juvenile hormone III (JH-III) has been determined by the use of combined gas chromatography-mass spectroscopy (GC-MS) in whole body extracts of the larvae, prepupae, pupae and adults of Drosophila hydei. A characteristic JH-III titer curve was established by use of the hormone derivatives. No other juvenile hormone homologs were detected.
JH-III shows a broad peak maximum of about 30 pmol/g fresh weight during the last larval instar, whereas only traces of the hormone are detectable at pupariation. Prepupae and pupae exhibit about the same JH-III level. In older pupae and in the pharate adults there was no JH-III detectable but it reappeared soon after emergence. Low values of JH-III are found in young male and female flies. The JH contents rise to distinct peaks in older and reproductive adults, both in male and female animals.
Effect of Extracellular Alkali Metal Salts on the Electric Parameters of Human Erythrocytes in Normal and Pathological Conditions (Homozygous β-Thalassemia)
Authors: Ballario C. , Bonincontro A. , Cametti C. , Rosi A. , Sportelli L. 
Published: August 2018

Abstract
The conductivity of human erythrocyte cells dispersed in various uni-univalent electrolyte solutions (NaCl, KCl, LiCl, CsCl; 0.15 ᴍ) have been measured in the frequency range from 10 KHz to 100 MHz at five temperatures between 5 and 45 °C. The results were analyzed in the light of the theory of conductivity polarization of a suspension of ellipsoidal particles covered with two confocal shells.
Differences in the electrical parameters of the membrane between normal and homozygous β-thalassemic cells have been evidentiated.
Catabolism of (R)-Amygdalin and (R)-Vicianin by Partially Purified ß-Glycosidases from Prunus serotina Ehrh. and Davallia trichomanoides
Authors: Kuroki Gary , Lizotte Pauline A. , Poulton Jonathan E. 
Published: August 2018

Mature black cherry (Prunus serotina Ehrh.) seeds accum ulate high levels of the cyanogenic disaccharide (R)-amygdalin. Extracts from these seeds contain two β-glycosidases which have been identified and completely resolved by DEAE-cellulose ion-exchange chromatography. Amygdalin hydrolase hydrolyzed (R)-am ygdalin at an optimum pH of 5.5, releasing (R)-prunasin and D-glucose. This enzyme showed highest activity towards (R)-am ygdalin and failed to hydrolyze (R)-prunasin. linamarin, β-gentiobiose and cellobiose. A distinct β-glycosidase, prunasin hydrolase, displayed a pronounced preference for (R)-prunasin, hydrolyzing this cyanogenic monosaccharide at an optimum pH of 6.5 to mandelonitrile and D-glucose. Prunasin hydrolase was inactive towards (R)-am ygdalin, linamarin, and β-gentiobiose. Both enzymes showed significant activity towards the artificial substrates β-ONPGlu and β-PNPGlu but did not hydrolyze α-PNPGlu. In view of the pronounced specificity of these enzymes towards endogenous cyanogens, it is concluded that upon disruption of black cherry seeds (R)- amygdalin is catabolized to mandelonitrile in a stepwise manner (the sequential mechanism) by amygdalin hydrolase and prunasin hydrolase with (R)-prunasin serving as intermediate.
Young fronds of Davallia trichomanoides are rich sources of (R)-vicianin (the β-vicianoside of (R)-mandelonitrile). A β-glycosidase, vicianin hydrolase, has been partially purified from frond extracts by ion-exchange chromatography. At the optimum pH of 6.0, this enzyme showed highest hydrolytic activity with (R)-vicianin, although both (R)-am ygdalin and (R)-prunasin could be hydrolyzed at approximately 15% of the rate observed with (R)-vicianin. It failed to hydrolyze β-gentiobiose, cellobiose, linamarin and α-PNPGlu. Closer exam ination revealed that (R)-vicianin and (R)-amygdalin were hydrolyzed at the aglycone-disaccharide bond (the simultaneous mechanism) yielding mandelonitrile and the respective disaccharides vicianose and β-gentiobiose
About the Similarity between Polymaleic Acid and Water Soluble Humic Fractions
Authors: Martin F. , Gonzalez-Vila F. J. , Lüdemann H.-D. 
Published: August 2018

The content of aromatic units in polymaleic acid (PMA) prepared by standard procedures is determined by C -13 NMR and three different oxydation procedures. It is shown that all destructive oxydation procedures lead to an aromatic carbon content that is significantly higher than the aromaticity content expected from the m ethod of preparation and derived from the C-13 NMR spectra.
It is concluded, that benzenecarboxylic acids are formed in the process of oxydation of PMA. The yield increases with the oxydative strength of the m ethod applied
Chemosystematics of Japanese Heterotropa (Aristolochiaceae)
Authors: Hayashi Nanao , Maeshima Kazuyuki , Murakami Tadayuki , Komae Hisashi 
Published: August 2018

Abstract
A survey of chemical composition of forty-four species of Heterotropa growing in Japan and Formosa showed that four chemical groups could be distinguished and that two routes of distribution to Japan from China may be suspected on the basis of phenylpropane components.
Two Dimensional Double-Quantum and COSY Spectra of Porcine Adenylate Kinase
Authors: Rösch Paul , Gross Karl-Heinz 
Published: August 2018

Abstract

1H double-quantum and COSY NMR-spectra of the porcine protein adenylate kinase have been obtained in order to assign aromatic spin systems within this protein, which contains seven tyrosyl, five phenylalanyl, and two histidyl residues. Double-quantum spectroscopy in its simple form allowed the assignment of five connectivities in the aromatic region and therefore proved inferior to COSY, which allowed the assignment of connectivities within nine aromatic residues.
Polycation-Cell Surface Interactions and Plasma Membrane Compartments in Mammals. Interference of Oligocation with Polycationic Condensation
Authors: Antohi Stefan , Brumfeld Vlad 
Published: August 2018

Abstract
At lower concentrations, polyarginine, polylysine, protamine, histones H 1, H2A, H2B and H3 cause lysis of human erythrocytes, whereas at higher concentrations inner histones are not hemolytic but induce only surface condensation and alterations in the cell-shape. Antibody coated erythrocytes treated with polyarginine result in ghost-like spheres having globular bodies 1 μm in diameter on the surface. Human fibroblasts and lymphocytes, and Ehrlich ascites cells treated with polyarginine also form surface globular bodies similar in size. Nucleate cell-poly-arginine mixtures with lower polycation doses result in cytolysis, while higher polycation doses produce pyknosis of the cell surface accompanied by reorganization of a membrane-like structure. Changes in spectrofluorometric values result from 1,6 -diphenyl-1,3,5-hexatrien binding to cell lipids, match the plasma membrane alterations. Reciprocal shake incubation am plifies and/or conditions these polycation-induced alterations. The homogeneity of pyknotic surface bodies and the apparent polycationic membrane reorganization requiring oscillatory friction forces suggest the preexistence of a multizonal glycocalyx distribution corresponding to plasma membrane compartments. The possible role of this compartmentalization in receptor and membrane recycling, as well as the involvement of reversible catalytic-like polycation condensation in macromolecular changes are discussed.
Electron Microscopic Study of the Polymyxin Treated Goat Erythrocytes
Authors: Mandal T. K. , Chatterjee S. N. 
Published: August 2018

Abstract
Polymyxin B produced dose dependent changes in the surface topography of the goat erythrocyte cells. Transformation from the normal biconcave discs through crenated structures to the final rounded or spherical shape was recorded by scanning electron microscopy. A maxim um of three to four crenations per cell was recorded corresponding to a polymyxin dose of 15.62 ng/ml. Transmission electron microscopy of the ultrathin sections of treated or untreated erythrocytes indicated that the crenations were formed by protrusions of the plasma membrane, occurring presumably because of the local increase of membrane fluidity after polymyxin treatment. Changes in the shape of the erythrocytes to the ultimate rounded forms were also indicated by the transmission electron microscopy.
Statistical Analysis of Quantum Bump Parameters in Limulus Ventral Photoreceptors
Authors: Keiper Winfried , Schnakenberg Jürgen 
Published: August 2018

Abstract
A statistical analysis of current quantum responses (“bumps”) to the absorption of single photons in the ventral photoreceptor of Limulus is presented. The analysis is performed in terms of bump parameters among which two groups are distinguished: “time-like parameters” with distributions independent of individual cells and “current parameters” the distribution of which differ for different cells. The analysis yields a set of “primary” parameters with mutually uncorrelated fluctuations. The results are interpreted by a new model formulation on the basis of a transmitter hypothesis for the transduction. The model separates latency from amplification and postulates the existence of different sources of fluctuations among which one includes individual cell properties.
Multiple Periodicities in the Circadian System of Unicellular Algae
Authors: Hoffmans-Hohn Margarete , Martin Wolfgang , Brinkmann Klaus 
Published: August 2018

Abstract
Three periodicities in the circadian range are observed when measuring circadian parameters of unicellular organisms in long running experiments (more than 15 days). This is demonstrated for different organisms (Chlamydomonas, Euglena, Chlorella) and different parameters (auto­ kinesis, extracellular pH, CO2- and O2-partial pressure). Having excluded analytical and experimental artefacts (i.e. filter leakage and subpopulation effects), the multiple periodicities have to be interpreted in a physiological model. The three periodicities always exhibit two common features: The locations of the side peaks are symmetrical to the middle peak and their energy contribution is always the same. We therefore favour the model of multiplicative coupling between the circadian oscillator and a low frequency oscillator modulating the amplitude of the circadian rhythm. Since the low frequency rhythm is not correlated to any exogenously running periodicity of the experimental surroundings, it is considered as generated by an endogenous oscillator. This shows the existence of different biological long time oscillators in one single cell and contradicts the so-called master-clock hypothesis stating that one cell has only one clock related oscillator.
Notizen: Analysis of a Sex-Attractant System in the Noctuid Moth Rhyacia baja Schiff
Authors: Priesner Emst 
Published: August 2018

Abstract
Binary combinations of (Z)-7-dodecenyl acetate and (Z)-9-tetradecenyl acetate in a 1/10 ratio were highly attractive to Rh. baja males in field trapping tests conducted in southern Germany. Trap captures increased further on adding 0.1 or 0.3% of (Z)-5-dodecenyl acetate to this lure; higher amounts of this chemical were strongly inhibitory, as were additions of > 3% of (Z)-11-hexa-decenyl acetate. The trapping data are considered in terms of electrophysiological responses of five types of antennal receptor cells.
Metabolie Activity of Hydroxycinnamic Acid Glucose Esters in Cell Suspension Cultures of Chenopodium rubrum
Authors: Strack Dieter , Bokern Maria 
Published: August 2018

Abstract
Cell suspension cultures of Chenopodium rubrum accumulate high amounts of metabolically active glucose esters of p-coumaric and ferulic acid. Pulse-labelling experiments using [14C]phenylalanine and application of the phenylalanine ammonia-lyase (PAL) inhibitor L-α-aminooxy-β-pnenylpropionic acid (AOPP) revealed that the glucose esters are subject to high turnover. A considerable portion of the ferulic acid was found as an insoluble component, probably bound to cell wall material. Application of m-fluoro-DL-tyrosine (MFT), an effective inhibitor of tyrosine biosynthesis via L-arogenate, markedly increased the amount of 1-p-coumaroyl-and 1-feruloyl-glucose accumulated.
Functional and Regulatory Properties of H+ Pumps at the Tonoplast and Plasma Membranes of Zea mays Coleoptiles
Authors: Hager A. , Biber W. 
Published: August 2018

Abstract
A microsomal membrane fraction (6000 x g supernatant of a cell homogenate), isolated from coleoptiles of Zea mays, was separated by isopycnic sucrose density gradient centrifugation in the presence of EDTA and without a prior pelleting step to avoid irreversible sticking of different membrane species. The membrane fractions were characterized by assaying commonly used marker enzymes, and the levels of activity investigated of ATP hydrolysis, ATP-dependent H+ transport, and co- and countertransport of ions, such as Cl- , fumarate2-, K+ and Li+. The following results were obtained:
(1) ATP hydrolysis is performed by different enzymes associated with different membranes:
- vacuolar acid phosphatase (AP; inhibited by molybdate);
- Golgi phosphatase, revealing IDPase, pNPase and ATPase activity (not inhibited by molybdate);
- ATPase activity of residual submitochondrial particles (sensitive to azide);
- a H+-translocating ATPase at tonoplast membranes (Km(ATP) = 0.29 mᴍ; pH 7.5; stimulated by uncouplers and completely inhibited by NO-
3);
- the H+-translocating ATPase of the plasmalemma (Km(ATP) = 0.39 mᴍ at pH 6.5, inhibited by vanadate, but not by NO-
3). The latter activity is evident only after an osmotic shock, indicating that PL vesicles primarily exist as inside-in-vesicles.
(2) ATP-fueled H+ pumps are localized at tonoplast (TO) and plasmalemma (PL) vesicles, they differ to some extent in their properties:
(a) The PLH+ pump has a very narrow pH optimum and exhibits highest levels of activity at pH 6.5 with a pronounced increase of activity between pH 7.5 and 6.5 (properties, obviously important in vivo for the regulation of active H+-extrusion by certain growth substances, which affect the cytoplasmic pH (Hager and Moser, Planta 1984, in press); in contrast, TO H+ pumps show a considerably wider pH optimum with highest levels of activity around pH 7.5.
(b) In variance to the PL H+ pump the activity of TO pumps (Km(ATP) = 0.24 mᴍ) is regulated via the oxidation state of essential thiol groups. Their oxidation to the S -S - form (e.g. by blue light in the presence of a flavin) causes an inactivation, whereas a re-reduction by GSH or cystein restores the activity [51].
(c) The ATP-fueled H+ transport into TO vesicles depends on an anion co-transport; most effective is Cl- , but there is also a stimulation by organic ions, C4 and C5 dicarboxylates, such as malate, succinate, fumarate, 2-oxoglutarate and aspartate; NO-
3 is inhibitory.
(d) H+-transport into sealed PL vesicles is also anion dependent. In this case, however, NO-
3 is as effective as Cl-.
(3) The TO membranes contain a H+/K+ exchange mechanism responsible for a secondary active K+ uptake into the vacuole. This mechanism could be the reason for a lower (ATP dependent) acidification of TO vesicles in the presence of K+ compared with Li+. - Similar effects are observed with plasmamembrane vesicles, but in this case there is still the question whether a H+/K+-exchange, a K+ channel, or both are acting.
Octopamine Modulates the Sensitivity of Limulus Ventral Photoreceptor
Authors: Stieve H. , André E. 
Published: August 2018

Abstract
The effect of extracellularly applied octopamine (10-5mol/l) on the receptor potential of the Limulus ventral photoreceptor was studied. Octopamine increases the sensitivity of the photoreceptor in the light-adapted state more than in the dark-adapted state. Extracellular application of phentolamine (10-5mol/l) has an opposite, antagonizing effect. The octopamine effect, though reproducible in the individual experiment, varies greatly from preparation to preparation.
Dose Rate Dependence of Radiation Induced IgG Membrane Receptor Alteration [1]
Authors: Ojeda F. , Moraga D. , Guarda M. I. , Folch H. 
Published: August 2018

Abstract
Mouse lymph node lymphocytes are irradiated at differ­ent dose rates and the B-cell receptors to anti IgG are tested. The expression of receptors is inhibited by irradia­tion. It is shown that the effectivity of irradiation increases with decreasing dose rate suggesting that membrane dam ­ age may be important for situations of chronic irradiation or implant radiotherapy.
Isomeric Di-C-glycosylflavones in Fig (Ficus carica L.)
Authors: Siewek Fred , Herrmann Karl , Grotjahn Lutz , Wray Victor 
Published: August 2018

Two isomeric C-glycosides of apigenin (apigenin-6-C-glucosyl-8-C-arabinoside (schaftoside), apigenin-6-C-arabinosyl-8-C-glucoside (isoschaftoside)) were isolated from leaves of Ficus carica with preparative HPLC.
1The glycosides were identified by UV-, 1H-NMR-, 13C-NMR-spectroscopy and FAB-MS.
Their concentration in fruits and leaves were determined by gradient HPLC on reversed phase material.
Inhibition of Photosystem II by UV-B-Radiation
Authors: Tevini M. , Pfister K. 
Published: August 2018

Abstract
The effect of UV-B-radiation on PSII activity of spinach chloroplasts was analyzed by measuring the integrity of the herbicide-binding protein (HBP 32), by measurement of fluorescence induction in the presence of Diuron (DCMU), and by mathematical analysis of the fluorescence induction curves. It was shown that UV-B inactivates the PSII α-centers but not PSII β-centers. However, the possibility cannot be excluded that in addition the donor site of PSII near the reaction center is attacked by UV-B-radiation.
Isolation of Populations of Antipeptide Antibodies Directed against Different Epitopes of the Same Fragment
Authors: Chersi Alberto , Greger Christiane , Houghten Richard A. 
Published: August 2018

Abstract
Rabbit antibodies against small peptides may be composed by subpopulations recognizing different epitopes made likely by few aminoacids. This explains the frequent crossreactivity of antipeptide antibodies with unrelated peptides.
A suitable use of immunoadsorbents is suggested to obtain truly specific antibodies able to react with restricted amino acid sequences.
Veränderung des Tocochromanolmusters einiger Pflanzenöle (Sojabohne, Lupine, Sonnenblume und Weizen) während Keimung und Wachstum / Alteration of Tocochromanol Pattern in Some Plant Oils (Soybean. Lupine. Sunflower and Wheat) during Germination and Growth
Authors: Schulz Hartwig , Lausch Gabriele , Feldheim Walter 
Published: August 2018

Abstract
Seed, sprout and plant oils from soybean (Soja hispida), lupine (Lupinus mutabilis), sunflower (Helianthus annuus) and wheat (Triticum aestivum) were assayed for their tocochromanol content and composition. High-performance liquid chromatography (HPLC) with fluorescence detection was used to determine tocopherols and tocotrienols of laboratory-extracted oils. In general, leaves of lupine, soja, and wheat with a high chlorophyll-a-content also were found to be rich of alpha-tocopherol; roots contained very little or no tocopherol. Contents of gamma-and delta-tocopherol in soja and lupine decreased during germination and growth, whereas the alpha-tocopherol concentration increases significantly. This evidence suggests that non-alpha-to-copherols might be methylated enzymatically to alpha-tocopherol. Tocochromanol pattern of wheat also changes characteristically in an analogous manner during plant development. Germ i­ nation of sunflower seeds also resulted in a conversion of beta-and gamma-tocopherols and in a slight decrease of the predominantly occurring alpha-tocopherol. In relation to the lipid content, the concentration of total tocopherols in oil plants increases significantly during growth. Possible implications for the biosynthesis of tocochromanols are discussed.
Quinolizidine Alkaloids as Nitrogen Source for Lupin Seedlings and Cell Cultures
Authors: Wink M. , Witte L. 
Published: August 2018

Abstract
The alkaloid patterns during germination and seedling development of Lupinus polyphyllus, L. angustifolius, L. albus, L. pubescens, Cytisus scoparius, Baptisia australis, Spartium junceum and Laburnum anagyroides were studied by capillary glc and EI-MS and CI-MS. The alkaloid contents were relatively high in the seeds and decreased by 20-100% during germination and the early developmental stages. The plants with fully developed leaves were able to synthesize new alkaloids. The decrease of alkaloid concentrations during germination was interpreted in terms of alkaloid turnover and use of the alkaloidal nitrogen for seedling development. The ability of plants to rely on the alkaloidal nitrogen as a nitrogen source could also be shown in lupin cell cultures which could survive and even grow on media which contained sparteine as the sole nitrogen source.
Die Kristallstruktur des Ectoin, einer neuen osmoregulatorisch wirksamen Aminosäure / The Crystal Structure of Ectoine, a Novel Amino Acid of Potential Osmoregulatory Function
Authors: Schuh Willi , Puff Heinrich , Galinski Erwin A. , Trüper Hans G. 
Published: August 2018

Abstract
The crystal structure of ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) isolated from the extremely halophilic phototrophic bacterium Ectothiorhodospira halochloris was determined by X-ray analysis. This novel cyclic amino acid forms zwitterionic molecules with delocalized π-bonding in the N-C-N group of the hydrated pyrimidine ring. The molecules are connected by N-H ...O hydrogen bonds. The excellent solubility of ectoine in water can be explained by its structural features which also account for its function as a compatible solute in halophilic bacteria.
A Disappearance of a 24-kDa Acid-Soluble Protein from Liver Chromatin of Normal and Starved Hens Following ᴅ-Galactosamine Administration
Authors: Pałyga Jan 
Published: August 2018

Abstract
Normal and starved adult chickens were injected intraperitoneally with ᴅ-galactosamine hydro­ chloride (0.5 g/kg body weight) and 6 h later liver chromatin acid-soluble proteins were isolated. These proteins were resolved by a two-dimensional polyacrylamide gel electrophoresis in the presence of non-ionic detergent, Triton X-100, in the first dimension and anionic detergent, sodium dodecyl sulfate, in the second dimension. Although spotting patterns of acid-soluble chromatin proteins were remarkably similar between normal and starved control birds and those receiving ᴅ-galactosamine, a disappearance of a 24-kDa protein after administration of this agent was found. Moreover, it was shown that this protein was also completely absent in the chicken erythrocyte chromatin which was known to be inactive in RNA synthesis.
It seems that the disappearance of the 24-kDa chromatin protein may be associated with inhibiting of transcription in hen liver after ᴅ-galactosamine administration and during hen erythrocyte maturation.