bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monospecific Antibody against 5-Methyl-Cytidine for the Structural Analysis of Nucleic Acids
Authors: Mastronicolis Sofia K. , Kapoulas Vassilios M. , Kröger Hans 
Published: August 2018

Abstract
Anti 5-methyl-cytidine antibodies might be useful agents for the detection and localization of 5-methyl-cytidine of nucleic acids, but only if the antibodies recognize this nucleoside with sufficient specificity. A conjugate containing 18 moles of 5-methyl-cytidine per mole of BSA was prepared and antibodies directed against this nucleoside hapten were produced by immunization of rabbits (as determined by gel diffusion in agar containing excessive amounts of the carrier). A slight crossreaction of cytidine-BSA was eliminated by adsorption on the cross-reacting antigen. Further purification of the antibodies was effected by chromatography on DEAE-Sephadex A-50 and a method for the rapid quantitation of the antibodies showed that 12.7% of the IgG protein are monospecific against 5-methyl-cytidine-BSA. Hydrolysis of antibodies with insolubilized pa­pain produced monovalent Fab fragments which were identified by SDS-Disk-electrophoresis. A two stage method for cross linking the immunoproteins to ferritin by glutaraldehyde was used. The isolation of immunoferritin conjugates by Bio-Gel A 1.5 m column chromatography is described. The identification of the effluents was made by glycerin density gradient ultracentrifugation. The results were visualized by electron microscopy after the treatment of immunoferritin conjugates with (methylated and unmethylated) denaturated DNA, fractionation on the glycerine density gradient, and the spreading by a modification of drop technique.
Über die oxidative Hauptkettenspaltung einiger Nukleinsäuren — Pulsradiolytische Untersuchungen / On the Oxidative Main-Chain Scission of Nucleic Acids — Pulse Radiolysis Studies
Authors: Denk Otmar , Schnabel Wolfram 
Published: August 2018

Abstract
Polyriboadenylic acid, polyribocytidylic acid and polyribouridylic acid were irradiated with 16 MeV electrons in aqueous solution. Part of the OH radicals generated during the radiolysis of water reacted with the sugar moieties of the polynucleotides. Subsequently formed peroxyl radicals reacted with each other thus forming oxyl radicals whose's decay led to main-chain scissions with the consequence of a decrease of the light scattering intensity (LSI). In the case of single-stranded polynucleotides, the analysis of the LSI decay curves revealed the occurrence of two processes. The rapid mode was assigned to the intramolecular and the slow mode to the intermolecular reaction of peroxyl radicals. For the rate constant of the rapid process (activation energy: 5 kcal/mol) a pronounced kinetic salt effect was observed.
In the case of double-stranded polynucleotides (polyA and polyC at pH 4, poly(A+U) at pH 8) the same effects were observed as with native calf thymus DNA in a former study [9]: The LSI decreased only after a critical dose was surpassed. A rapid process was followed by a slow one. The slow process is assigned to the melting of H-bridges located at bases between main-chain scissons in the double helix. The rapid process corresponds to the separation of fragments formed by two single strand breaks laying very close to each other on opposite sites in the double helix.
ATPases of the Cat Carotid Body and of the Neighbouring Ganglia
Authors: Starlinger H. 
Published: August 2018

Abstract
The average ATPase activity in homogenates of the cat carotid body is found to be 20 nmol Pi liberated per minute per mg fresh tissue weight at 25 °C. ATPase activity in the nodose ganglion and the superior cervical ganglion is found in the same range. Most of the activity remains in the supernatant after removal of the mitochondria by centrifugation. The activity is inhibited by ouabain only marginally (ganglia) or not at all (carotid body). In all these organs up to 80% of the activity is seen in the absence of Mg2+ and the presence of increasing concentrations of Ca2+.
Notizen: Coenzyme Binding at Different Ionization States of Cytoplasmic and Mitochondrial Malate Dehydrogenase
Authors: Schwerdtfeger Klaus , Woenckhaus Christoph , Parker David M. , Holbrook John J. 
Published: August 2018

Abstract
pH-titrations with NADH show two ionizable groups in mitochondrial and cytoplasmic malate dehydrogenase, the first with a pKa in the range 6.8 -8.3 for the mitochondrial and 6.4-7.8 for the cytoplasmic enzyme, the second with a lower limit at 10.2 resp. 11. Comparison with bis-(dihydronicotinamide)-dinucleotide and dihydronicotina-mide-ribosyl-P2-ribose-pyrophosphate instead of NADH indicates that the second alkaline ionization is caused by a residue placed near the adenine binding site of the active centre of the two isoenzymes. Binding studies with NADH and NAD+ give evidence for the participation of a group in the mitochondrial enzyme with pKa 6.8, deprotonation of which is necessary for detectable association of NAD+. In contrast the fixation of NAD+ to the cytoplasmic enzyme is independent of pH.
6-C-α-L-Rhamnopyranosylapigenin 7-O-β-ᴅ-glucopyranoside (Isofurcatain 7-O-β-ᴅ-glucoside), a New Flavone Glycoside from Metzgeria furcata
Authors: Markham Kenneth R. , Theodor Renate , Mues Rudiger , Zinsmeister H. Dietmar 
Published: August 2018

Abstract
The isolation of 6-C-α-ʟ-rhamnopyranosylapigenin (isofurcatain) 7-O-β-ᴍ ᴅ-glucopyranoside, from Metzgeria furcata var. ulvula is described together with its identification. This is a new natural product, as also is isofurcatain.
Demethylation, Methylation and 3′-Hydroxylation of Isoflavones by Fusarium Fungi
Authors: Weltring K.-M. , Mackenbrock K. , Barz W. 
Published: August 2018

Abstract
Several introductionary reactions of isoflavone metabolism by Fusarium fungi are reported. Fusarium avenaceum hydroxylates formononetin in the 3′-position yielding 3′,7-dihydroxy-4′-methoxyisoflavone (calycosin). 3′-Hydroxylation of biochanin A to 3′,5,7-trihydroxy-4′-methoxyiso-flavone (pratensein) has been observed with Fusarium oxysporum f. sp. lycopersici and Fusarium oxysporum f. sp. lini. Depending on the growth medium Fusarium proliferatum metabolises for­mononetin either by 7-O-methylation or by 4′-O-demethylation.
Polynucleotide Phosphorylase from a Cyanobacterium (Synechococcus sp.): Subunit Composition and Properties
Authors: Nolden Wolf-Thomas , Richter Gerhard 
Published: August 2018

Abstract
Polynucleotide phosphorylase from cells of the cyanobacterium Synechococcus sp. has been purified 1400-fold by an improved procedure. The enzyme purified to homogeneity and lacking nuclease, phosphatase and protease contaminations reveals a single band of ADP polymerizing activity upon polyacrylamide gel electrophoresis under nondenaturing conditions which cor­responds to a molecular mass of about 275 000. The enzyme migrates as a single polypeptide of Mr ≈ 70 000 when subjected to gel electrophoresis in the presence of dodecyl sulfate indicating a composition of α4 for the native enzyme molecule. The isoelectric point of the purified enzyme as determined by isoelectric focusing was found to be at 4.2 ± 0.1. Polynucleotide phosphorylase of Synechococcus is preferentially activated by Mg2+; KCl has a significant stimulatory effect.
Equilibrium and Kinetic Studies of Calcium Transport and ATPase Activity in Sarcoplasmic Reticulum
Authors: Inesi G. , Kurzmack M. , Kosk-Kosicka D. , Lewis D. , Scofano H. , Guimaraes- Motta H. 
Published: August 2018

Abstract
A number of equilibrium and kinetic measurements are presented to characterize the partial reactions of the ATPase and transport cycle in sarcoplasmic reticulum vesicles. The cycle begins with calcium and nucleotide binding on sites available on the outer surface of the vesicles. A phosphorylated enzyme intermediate is then formed, and the calcium sites are subjected to a change in their orientation and their affinity for calcium. It is shown that steps involved in calcium release on the inner side of the vesicles are rate limiting for the cycle, and are followed by hydrolytic cleavage of the intermediate with release of inorganic phosphate and recycling of the enzyme.
Enzymatic Synthesis of Sinapine from 1-O-Sinapoyl-β-ᴅ-glucose and Choline by a Cell-Free System from Developing Seeds of Red Radish (Raphanus sativus L. var. sativus)
Authors: Strack Dieter , Knogge Wolfgang , Dahlbender Brigitte 
Published: August 2018

A cell-free system from developing seeds of red radish (Raphanus sativus L. var. sativus) catalyzed the transfer of the sinapoyl moiety of 1-O-sinapoyl-β-ᴅ-glucose to choline to form O-sinapoylcholine (sinapine). A wide range of proportionality with respect to incubation time and protein concentration was found in the determination of this enzymatic activity using a high performance liquid chromatographic (HPLC) method. The transacylase activity showed an absolute acceptor specificity towards choline and a high hydroxycinnamoyl donor specificity with 1-sinapoylglucose. Maxim|al rate of sinapine formation was found to be around pH 7.0 in 0.08 M potassium phosphate buffer. The apparent Km values were 0.30 mм for 1-sinapoylglucose and 7.64 mм for choline.
Change in extractable transacylase activities from different stages of seed development correlated well with the in vivo accumulation kinetics of sinapine. Maximal activity around 36 pkat seed-1 and 129μkat kg-1 protein was extracted from dark-green immature seeds, which are in the process of rapid sinapine accumulation. About 20% of this activity still has been found in dark-brown mature seeds. This enzymatic acitivity refers to an enzyme which can be classified as 1-sinapoylglucose: choline sinapoyltransferase (SCT).
Chlorophyll-Lipid-Interactions in Monomolecular Layers
Authors: Heithier H. , Möhwald H. 
Published: August 2018

Mixed monolayers containing chlorophyll a and dim yristoyllecithin (DML) have been investigated by simultaneous thermodynamic, fluorescence and absorption spectroscopic measurements. It has been shown that the solubility limit of chlorophyll a in the fluid, as well as in the solid lipid matrix, is above 20 mol%. This contrasts to previous findings for pheophytin a containing monolayers and indicates the existance of an interaction between the phospholipid head group and the central Mg atom.
A fluorescence decrease on solidifying the monolayer was observed and it is suggested that it is due to an enhanced self quenching as a consequence of the reorientation of the porphyrin rings, accompanying the phase transition
Zusammensetzung und Akkumulation des ätherischen Öls in Matricariae Radix (2. Mitteilung) / Composition and Accum ulation of Essential Oil in Matricariae Radix (2. Com munication)
Authors: Reichling Jürgen , Bisson Walter , Becker Hans , Schilling Gerhard 
Published: August 2018

The essential oil of Matricaria chamomilla roots has been investigated. Besides the known compounds for this plant organ trans-β-farnesene,trans-α-famesene, chamomillaester I and II, we found the two spiroether only described for the aeriel parts. β-caryophyllene, cis-caryo hyllene and caryophyllenepoxid are found for the first time in Matricaria chamomilla. One of the main constituents is a hitherto unknown sesquiterpene-alkohol with muurolene-structure. With the aid of spectroscopical data (1H-NMR, 13C-NMR, MS) we determined its structure. We propose the name chamomillol for the new compound.
Besides the known resin ducts longitudinally orientated we found resin ducts transversally orientated and oil cells
Circulardichroism of C-Phycocyanin: Origin of Optical Activity in Denatured Biliproteins and Evidence for an Intermediate during Unfolding
Authors: Lehner Harald , Scheer Hugo 
Published: August 2018

The circulardichroism spectra (cd) of native and (partially) urea-denaturated C-phycocyanin (PC) in the spectral range 700-210 nm are presented. The large ellipticities observed in the chromophoric region of native PC are retained in the fully denatured state (8 ᴍ urea). This is similar to the behavior of the red form of phytochrome (Pr), but in contrast to C-phycoerythrin (PE). These differences are rationalized in terms of epimeric equilibria between P- and M-helix shaped chromophores. Depending on the number and location of the chirality centers present in the tetrapyrrol moities a priori, the excess populations of the inherently chiral P- and M-helices differ, thus accounting for large (PC, Pr) or small (PE) ellipticities in the denatured pigments. Hence, the large optical activity observed for the former is generated by an excess population of the P-helix induced by the asymmetric C-2, C-3 and C-3'. In PE the additional chirality center at C-16 counteracts the influence of the others. The excess population of the inherently chiral species is therefore lowered, in agreement with the nearly vanishing cd reported for denatured PE.
The cd has also been studied at intermediate urea concentrations. Unfolding of PC with urea can be interpreted from these data as a stepwise process. Monitoring the urea induced unfolding of PC by cd at different wavelengths (λ = 220, 345, and 610 nm); the “melting point” of the apoprotein (4 -5 ᴍ urea) coincides with the extrema of the titration curves obtained in the chromophore region (345, 610 nm). These results give direct evidence for the existence of an intermediate species whose population reaches a maximum at 4-5 ᴍ urea.
Uptake and Conversion of Three Different 5-Ring Polycyclic Aromatic Hydrocarbons (PAHs) in Cell Suspension Cultures of Various Chenopodiaceae-Species
Authors: Harms Hans 
Published: August 2018

Three l4C-labelled 5-ring PAHs, benzo(a)pyrene, dibenz(a,h)anthracene and perylene were added to various cell suspension cultures of plants belonging to the Chenopodiaceae family. The differently configurated 5-ring systems varied in uptake and metabolism. The uptake of benzo(a)pyrene was highest in all cell cultures tested whereas the assimilation of dibenz(a,h)an­thracene and perylene was significantly less. The uptake of benzo(a)pyrene and dibenz(a,h)- anthracene was highest in those cultures which showed the highest increase in biomass. In contrast the uptake of perylene was highest in cultures whose increase in biomass was less.
Previous investigations (H. Harms, W. Dehnen and W. Monch, Z. Naturforsch. 32 c, 321 -326 (1977)) showed that benzo(a)pyrene is metabolized to quinones and other oxygenated derivatives by Chenopodium rubrum cell cultures. It was demonstrated now that in further reactions these compounds are incorporated into insoluble fractions. With increasing time of incubation the amount of radioactivity in the extracted residue increased. The proportion of oxygenated derivatives formed seems to be correlated with the incorporation of radioactivity into insoluble fractions. Dibenz(a,h)anthracene turned out to be the most stable 5-ring system whereas perylene is metabolized to a certain extent but only small amounts of radioactivity could be detected in the extracted insoluble residue.
The experiments showed that plant cell cultures maintain their specific behaviour over long periods. On the other hand each of the chemical compounds, because of its molecular size and configuration, is subject to its own specific metabolism in plant systems.
Interconversion of Carotenoids and Quinones after Onset of Photosynthesis in Chloroplasts of Higher Plants
Authors: Grumbach K. H. 
Published: August 2018

The interconversion of carotenoids and quinones was investigated in beech and spinach leaves as well as isolated intact spinach chloroplasts following a dark-light transition. It is shown that isolated intact chloroplasts which are preincubated for 2 h at pH 7.6 in the dark and re­illuminated with strong white light are capable not only of deepoxidizing violaxanthin into antheraxanthin and zeaxanthin but simultaneously change the redox state of the plastoquinone- pool in their thylakoid membrane. At the same time as violaxanthin is deepoxidized plastohydroquinone-9 is oxidized to plastoquinone-9. If the light is turned off zeaxanthin is epoxidized into antheraxanthin and violaxanthin but no significant change in the redox state of the plastoquinone-pool occurred.
It is concluded that the deepoxidation of violaxanthin is connected to the photosynthetic electron transport in that way that an acidification of the intrathylakoidal compartment by the vectorial release of protons from the water photooxidizing enzyme system and the plastoquinone- pool is required for the activation of the violaxanthin deepoxidase. This may be taken as further evidence that violaxanthin deepoxidase is located at the inner side of the thylakoid membrane. Additional evidence for this location site is given by the observation that neither deepoxidation of violaxanthin nor photooxidation of plastohydroquinone-9 occurred after onset of photosyn­thesis if non cyclic electron transport was inhibited by DCMU.
Distribution and Variation of the Catalytic Activity of the Enzyme Responsible for Carthamin Synthesis in Safflower Seedlings
Authors: Saito Koshi , Takahashi Yoshiyuki , Wada Mizu 
Published: August 2018

Abstract
Catalytic activityof the enzyme which mediates the synthesis of carthamin was examined in the etiolated hypocotyl tissues of Carthamus tinctorius L. The enzyme was optimally active at pH 5.2 in citrate buffer. The activity of the enzyme was highest in the extract from 2-day-old seedlings after sowing and it declined sharply with tissue ageing. The enzyme activity was localized in the apical region of the seedlings and moreover it was preferentially associated with the cytosol fraction.
Further Studies on Induction of Enzymes of Phytoalexin Synthesis in Soybean and Cultured Soybean Cells
Authors: Leube Joachim , Grisebach Hans 
Published: August 2018

Abstract
The glucan elicitor from cell walls o f the fungal pathogen, Phytophthora megasperma f. sp. glycinea, caused a decrease in activity of 3-hydroxy-3-methylglutaryl coenzyme A reductase in wounded soybean cotyledons, whereas wounding alone led to an increase in the activity of this enzyme. A decrease o f HMG -CoA reductase activity after elicitor treatment was also found in soybean hypocotyls and soybean cell cultures.
In contrast to the activity o f HMG -CoA reductase, the activity of dimethylallylpyrophosphate: 3,6a,9-trihydroxypterocarpan dimethylallyltransferase increases after elicitor challenge of soy­bean cell cultures and after inoculation of soybean hypocotyls (cv Amsoy 71) with mycelium of either race 1 (incompatible) or race 3 (compatible) of P. megasperma.
Analoga des Hippurans: [103Ru]Ruthenocenoyl-glycin-Derivate. Synthese, Organ-Verteilung und Clearance /Analogue of Hippuran: Labelled Ruthenocenoyl-glycin. Synthesis, Organ Distribution and Clearance
Authors: Wenzel Martin , Schachschneider Gert 
Published: August 2018

The analogue of hippuric acid, ruthenocenoyl-glycine was synthesized and labelled with the γ-emitter 103Ru. As a by-product of the synthesis the labelled diamide from ruthenocene- dicarbonic acid and glycine was gained. With these ruthenocene derivatives the organ distribu­tions in mice and rats were measured.
All ruthenocene-glycine derivatives showed primary a high kidney accumulation followed by very rapid renal excretion. After application of the cytostatic PtCl2(NH3)2, causing toxic effects in the kidney of mice, the excretion of ruthenocenoyl-glycine is decreased. Biochemical data suggest the use of labelled ruthenocenoyl-glycine as a substitute for Iodo-labelled hippuran.
Preparation and Characterization of Actin from Liver
Authors: Jaberg B. 
Published: August 2018

G-actin was prepared from pork liver by gelfiltration on AcA 44 Ultrogel. The purity of the actin was 95-98% and the yield was 45-150 mg from 500 g liver, corresponding to a maximum efficiency of recovery of about 30%.
High viscosities of actin-enriched solutions were reduced by a specific pH-step. In SDS-gel electrophoresis a single band of about ~ 45000 daltons was seen. The G-actin was polymerizable as shown by high shear viscosity measurements. The isoelectric points of the β- and γ-isoactins were 5.6 and 5.7.
Effect of Electron Transfer Inhibitors and Uncoupling Agents on the Chlorophyll Fluorescence Lifetime during Slow Fluorescence Decline in Bean Leaves and Intact Chloroplasts
Authors: Kotova Elena A. , Il’ina Marina D. 
Published: August 2018

Abstract
Fluorescence measurements were performed with bean leaves and intact chloroplasts, which are characterized by a slow fluorescence decline. The fluorescence lifetime (ι) and the fluorescence relative quantum yield (φ) of intact chloroplasts, measured with the phase fluorometer, showed nearly proportional light-induced decrease with a halftime of ∼ 30 s, which was removed by 3-(3.4-dichlorophenyl)-1.1 -dimethylurea (DCMU), by 4.5,6,7-tetrachloro-2′-trifluoromethylbenzimidazole (TTFB). by carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP) at a low concentration and by gramicidin D. Simultaneously the slow light-induced increase in absorbance at 518 nm (ΔA518), reflecting thylakoid membrane energization, was eliminated. The data on ι of intact chloroplasts are original, the other results agree with literature data. In leaves, the slow light-induced fluorescence decline, with ι dropping from ∼ 2 to ∼ 0.6 ns, was abolished by FCCP at a concentration of 5 μm. However, while ι was stabilized at a level close to the initial (maximum) one or somewhat higher, φ became close to the minimum value. Besides, the amplitude of ΔA518 was lowered about three times. These effects seemed to be due to multiple action of FCCP as a protonophoric uncoupler and an electron transfer inhibitor. In the presence of another uncoupling agent, TTFB, which, besides, is a diuron-like inhibitor of the electron transfer in chloroplasts, we observed the light-dependent, but hardly linked to changes in membrane potential, great increase in ι of a leaf from ∼ 1.9 to ∼ 4 .3 ns, with φ decreasing slightly. Addition of DCMU together with FCCP to the incubation medium or infiltration of a leaf with DCMU alone stimulated the rise in ι only to ∼ 3 ns. The increase in ι of a leaf observed in the presence of FCCP and DCMU, and especially with TTFB, may be associated with protein conformation changes which (i) alter the lifetime of nanosecond recombination luminescence of the photosystem II and/or (ii) disturb excitation energy transfer from the light-harvesting chlorophyll a/b complex to other pigment-protein complexes.
The Influence of Cysteine on the Reaction of d-Guanosine with cis -Diamminedichloroplatinum (II)
Authors: Kulamowicz Irena , Olinski Ryszard , Walter Zofia 
Published: August 2018

Abstract
Mono-and bifunctional complexes of cis DDP and d-guanosine were isolated on Sephadex G-25. The presence of cysteine in incubation mixture resulted in the vanishing of bifunctional com plex of d-guanosine and the appearance of d-guanosine-cis DDP-cysteine complex in the eluted peak. It is also possible that the eluted peak contained no homogeneous product of the reaction.
Insulin Binding Sites Induced in the Tetrahymena by Rat Liver Receptor Antibody
Authors: Csaba G. , Kovács P. , Inczefi-Gonda Ágnes 
Published: August 2018

Abstract
Tetrahvmena cells treated with purified rabbit anti­ bodies to rat hepatocellular membrane exhibited a consider­ able increase in binding capacity on reexposure to the antibody 24 h later. Insulin binding was similarly enhanced by preexposure to the antibody, and vice versa, preex­ posure to insulin enhanced the later binding of rat liver receptor antibodies. This suggests that (1) the Tetrahymena and the rat possess similar insulin receptors, and (2) the receptor antibody is also able to induce imprinting for itself as well as for insulin. Concanavalin-A, noted for binding overlap with insulin, failed to induce imprinting either for insulin or for antibodies to receptors, whereas the latter did induce imprinting for Concanavalin-A.