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1983[X]
61Author    Jochen Berlin, Edgar Forche, Victor Wray, Joachim Hammer, Wolfgang HöselRequires cookie*
 Title    Formation of Benzophenanthridine Alkaloids by Suspension Cultures o f Eschscholtzia californica  
 Abstract    Suspension cultures of Eschscholtzia californica accum ulate the dihydro forms o f the benzo­ phenanthridine alkaloids sanguinarine, chelirubine, macarpine and chelerythrine, all o f which are known to be constituents o f the Eschscholtzia plant. U nder most experimental conditions dihydrochelirubine was found to be the main constituent of the cultured cells. The specific yields of alkaloids varied from zero to 1.7% on a dry weight basis depending on the m edia conditions. The highest specific yield was 1.5 m g/g dry weight or 13 mg/1 with the growth m edium B5. After transfer of the cells into the induction medium IM2 the alkaloid accum ulation increased to 17 mg/g dry weight and 146 mg/1. The induction m edium contained increased levels o f sucrose, decreased levels of phosphate and was devoid of phytohormones. The effect o f the various m edia conditions on the biosynthesis of phenolics was quite different to those found for the alkaloids. 
  Reference    Z. Naturforsch. 38c, 346 (1983); received February 7 1983 
  Published    1983 
  Keywords    Eschscholtzia californica, Suspension Cultures, Benzophenanthridine Alkaloids, Phenolics, Media Effects 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0346.pdf 
 Identifier    ZNC-1983-38c-0346 
 Volume    38 
62Author    Harald Lehner, Hugo ScheerRequires cookie*
 Title    Circulardichroism of C-Phycocyanin: Origin of Optical Activity in Denatured Biliproteins and Evidence for an Intermediate during Unfolding  
 Abstract    The circulardichroism spectra (cd) o f native and (partially) urea-denaturated C-phycocyanin (PC) in the spectral range 7 0 0 -2 1 0 nm are presented. The large ellipticities observed in the chrom ophoric region of native PC are retained in the fully denatured state (8 M urea). This is sim ilar to the behavior of the red form of phytochrome (Pc), but in contrast to C-phycoerythrin (PE). These differences are rationalized in terms of epim eric equilibria betw een P-and M-helix shaped chromophores. D epending on the num ber and location o f 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 form er 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 -l6 counteracts the influence of the others. The excess population o f the inherently chiral species is therefore lowered, in agreem ent with the nearly vanishing cd reported for denatured PE. The cd has also been studied at interm ediate urea concentrations. U nfolding of PC with urea can be interpreted from these data as a stepwise process. M onitoring the urea induced unfolding of PC by cd at different wavelengths (A = 220, 345, and 610 nm); the "melting po in t" o f the apoprotein (4 -5 M urea) coincides with the extrema of the titration curves obtained in the chrom ophore region (345, 610 nm). These results give direct evidence for the existence of an interm ediate species whose population reaches a m aximum at 4 — 5 M urea. 
  Reference    Z. Naturforsch. 38c, 353 (1983); received January 17 1983 
  Published    1983 
  Keywords    Phycocyanin, Phycoerythrin, Phytochrom, C irculardichroism, D enaturation 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0353.pdf 
 Identifier    ZNC-1983-38c-0353 
 Volume    38 
63Author    Fritz Thümmler, W. Olfhart Rüdiger, Edmund Cmiel, Siegfried SchneiderRequires cookie*
 Title    Chromopeptides from Phytochrome and Phycocyanin. NM R Studies o f the Pfr and P r Chromophore of Phytochrome and EyZ Isomeric Chromophores of Phycocyanin  
 Abstract    Chromopeptides were prepared by pepsin digestion of C-phycocyanin isolated from the cyano­ bacterium Spirulina m axim a and o f phytochrom e isolated from seedlings o f Avena sativa L. The chromopeptides were characterized by am ino acid analysis. The Z Z Z configurated chrom ophore of the phycocyanin peptide was transformed into its Z Z E configurated isom er by the m ethod of Falk et al. (Mh. C hem ie 111, 159—175, 1980) which had previously been applied to biliverdins. The 500 MHz 'H N M R spectrum o f the Z Z E configurated chrom opeptides confirmed that its chromophore has the 15 E configuration. Irradiation yielded the Z Z Z configurated isom er for which the 'H N M R spectrum was also recorded. N ative phytochrom e was irradiated at 660 nm to yield the maximum am ount of the Pfr from (about 75% of total phytochrome). By digestion in the dark the previously described Pfr chrom opeptide was obtained. The 500 MHz 'H N M R spectrum was com pared with that o f the Z Z E phycocyanin peptide. It confirmed the 15 £ con­ figuration of the Pfr chrom opeptide. Irradiation yielded the 15 Z configurated Pr chrom opeptide. Comparison of the high resolution 'H N M R spectra o f Pfr and Pr chrom opeptides revealed that not only the chrom ophore resonances but also those of some amino acids are changed by the Pfr -*■ Pr chrom opeptide phototransform ation. The results are discussed in term s of chrom ophore amino acid interaction. 
  Reference    Z. Naturforsch. 38c, 359 (1983); received February 2 1983 
  Published    1983 
  Keywords    Bilipeptides, C-Phycocyanin, High Resolution N M R Spectra, Photoisom erization, Phytochrom e 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0359.pdf 
 Identifier    ZNC-1983-38c-0359 
 Volume    38 
64Author    JonathanE. Poulton, Sun-In ShinRequires cookie*
 Title    Prunasin Biosynthesis by Cell-Free Extracts from Black Cherry (Prunus serotina Ehrh.) Fruits and Leaves  
 Abstract    Immature fruits and leaves o f black cherry (Prunus serotina Ehrh.) accumulate the cyanogenic glucoside prunasin (the /?-glucoside of (/?)-mandelonitrile). Cell-free extracts from these tissues catalysed the stereospecific glucosylation of (/?,S)-mandelonitrile to (/?)-prunasin at rates of 0.2 — 2.0 ^mol/h/mg protein. Uridine diphosphate glucose (ATm = 0.32rnM) acted as glucose donor. The optimum concentration of (/?,S)-mandelonitrile was 20 mM. Highest activity was exhibited at pH 7.0 —8.0 in Tris-phosphate buffer, and no additional cofactors were required. /?-Mercaptoethanol (14.5 mM), provided in the homogenization medium to prevent browning of homogenates, did not stimulate the rate o f prunasin production. In addition to (/?)-mandelo-nitrile (100%), significant activity was shown towards mandelamide (21%), benzyl alcohol (15%), mandelic acid (8%) and benzoic acid (153%), but not towards prunasin. Mandelonitrile glucosyltransferase activity was most stable at -20 °C in the presence o f 10% glycerol. 
  Reference    Z. Naturforsch. 38c, 369—374 (1983); received January 3 1983 
  Published    1983 
  Keywords    Black Cherry, Prunus serotina, Prunasin Biosynthesis, Cyanogenic Glycosides, O-Glucosyltransferase 
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 Identifier    ZNC-1983-38c-0369 
 Volume    38 
65Author    Fumiko Hirose, HiroshiA. ShiharaRequires cookie*
 Title    Comparison of Purine Metabolism in Suspension Cultured Cells of Different Growth Phases and Stem Tissue of Catharanthus roseus  
 Abstract    Catharanthus roseus (= Vinca rosea), Suspension Cultured Cells, Stem Tissue, Purine M etabolism The overall m etabolism o f [8-l4C]adenine, [8-14C]adenosine, [8-l4C]guanine, [8-14C]hypoxan-thine and [8-14C]inosine in suspension cultured cells o f the lag, cell division, cell expansion and stationary phases and stem tissue o f Catharanthus roseus was studied. On a fresh weight basis, absorption o f all purine bases and nucleotides by the cultured cells was 10 —400 tim es higher than that by the stem tissue. The conventional pathways o f purine salvage and degradation were operative both in the cultured cells and stem tissue. [8-14C]Adenine and [8-14C]adenosine were extensively salvaged to nucleotides and nucleic acids in both the cultured cells and the stem tissue. [8-l4C]-Guanine, [8-l4C]hypoxanthine and [8-14C]inosine were incorporated into either salvage products (nucleotides and nucleic acids) or degradation products (C 0 2, allantoin and allantoic acid) o f cultured cells and stem tissue. The highest incorporation rate expressed as a percentage o f absorbed 14C into the degradation products was observed in the lag phase (12h-old) cultured cells. Incorporation o f all precursors into nucleotides and bases was much higher in the stem tissue than in the culltured cells. 
  Reference    Z. Naturforsch. 38c, 375—381 (1983); received February 19 1983 
  Published    1983 
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 Identifier    ZNC-1983-38c-0375 
 Volume    38 
66Author    Hans HarmsRequires cookie*
 Title    Uptake and Conversion of Three Different 5-Ring Polycyclic Aromatic Hydrocarbons (PAH s) in Cell Suspension Cultures of Various Chenopodiaceae-Species  
 Abstract    Three 14C-labelled 5-ring PAHs, benzo(a)pyrene, dibenz(a,h)anthracene and perylene were added to various cell suspension cultures o f 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)an-thracene and perylene was significantly less. The uptake o f 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. Mönch, Z. Naturforsch. 32 c, 3 2 1 -3 2 6 (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 o f incubation the amount of radioactivity in the extracted residue increased. The proportion o f 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 o f 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 o f the chemical compounds, because of its molecular size and configuration, is subject to its own specific metabolism in plant systems. 
  Reference    Z. Naturforsch. 38c, 382—382 (1983); received December 30 1982/March 2 1983 
  Published    1983 
  Keywords    5-Ring Polycyclic Aromatic Hydrocarbons, Uptake, Metabolism, Plant Cell Suspension Cultures, Chenopodiaceae 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0382.pdf 
 Identifier    ZNC-1983-38c-0382 
 Volume    38 
67Author    Friedrich Jiittner, O. Ttm Ar BogenschützRequires cookie*
 Title    Geranyl Derivatives as Inhibitors o f the Carotenogenesis in Synechococcus PCC 6911 (Cyanobacteria)  
 Abstract    The ability of several geranyl derivatives to inhibit carotenoid synthesis in Synechococcus (Cyanobacteria) was measured using a cyanobacterial bioassay. The inhibitory activity o f differ­ ent molecules varied according to chain length and substituents. Pseudoionone, famesyl acetate, geranyl acetate, geranial and farnesol proved to be the most active derivatives tested. 6-Methylhept-5-en-2-one, farnesyl acetone, linalool and geranyl linalool exhibited no effect when employed in concentrations as high as 100 ppm. Besides phytofluene, C-carotene was accumu­ lated after application o f sublethal amounts o f active geranyl derivatives. Cell growth and chlorophyll a synthesis were only slightly affected under conditions were carotenoid synthesis was markedly inhibited. 
  Reference    Z. Naturforsch. 38c, 387 (1983); received January 26 1983 
  Published    1983 
  Keywords    Inhibitors, Carotenoid Synthesis, Pseudoionone, Famesol, Famesyl Acetate 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0387.pdf 
 Identifier    ZNC-1983-38c-0387 
 Volume    38 
68Author    K. H. GrumbachRequires cookie*
 Title    Interconversion of Carotenoids and Quinones after Onset of Photosynthesis in Chloroplasts of Higher Plants  
 Abstract    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 re­ illuminated with strong white light are capable not only o f deepoxidizing violaxanthin into antheraxanthin and zeaxanthin but simultaneously change the redox state o f the plastoquinone-pool in their thylakoid membrane. At the same time as violaxanthin is deepoxidized plasto-hydroquinone-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 o f the plasto-quinone-pool occurred. It is concluded that the deepoxidation of violaxanthin is connected to the photosynthetic electron transport in that way that an acidification o f 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 o f 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 o f photosyn­ thesis if non cyclic electron transport was inhibited by DCMU. 
  Reference    Z. Naturforsch. 38c, 393 (1983); received March 15 1983 
  Published    1983 
  Keywords    Carotenoids, Photosynthesis, Quinones, Xanthophyll Cycle 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0393.pdf 
 Identifier    ZNC-1983-38c-0393 
 Volume    38 
69Author    Andreas Sauer, Klaus-Peter HeiseRequires cookie*
 Title    The Influence o f the Glycerol-3-Phosphate Level in the Stroma Space on Lipid Synthesis of Intact Chloroplasts  
 Abstract    The G3P level in chloroplasts, rapidly isolated from spinach leaves during a light-dark cycle, oscillated between 2.5 and 4 nmol • mg-1 Chi, which corresponds to a concentration o f nearly 0.1 —0.2 mM. In order to study the role o f the stromal G3P level on chloroplast lipid biosynthesis, G3P uptake, measured by silicone oil centrifugation, has been correlated with the lipid synthesizing capacity o f intact spinach chloroplasts. The level of G3P in the chloroplast stroma was decreased by high orthophosphate (Pj) concentrations in the medium. This decrease was caused by a strong Pj transport into the stroma, which is counterbalanced by a release of phosphorylated metabolites including G3P, mediated by the translocator. But because the reduced stromal G3P concentration exceeded about 3 times that for half saturation o f the primary G3P acylation with oleoyl-ACP as preferred fatty acid donor, glycerolipid synthesis was not eliminated. Instead, the lowered G3P level in the stroma space limited the secondary acyla­ tion step, indicated by the reduced incorporation o f palmitic acid into the diglyceride fraction, and led to an accumulation o f free oleic acid. Thus, beside its function as primary acyl acceptor, the stromal G3P level apparently controls the pool size o f ACP bound palmitic acid by limitation o f the chain elongation step from palmitoyl-to stearoyl-ACP in order to induce the specific palmitic acid channeling into the C-2-position of chloroplast lipids by the secondary G3P acylation. A similar function may be due to fatty acid consuming reactions from outside the chloroplast like acyl-CoA thioester formation in the outer envelope membrane, stimulated by exogenous CoA and ATP. In contradiction to earlier findings intact Percoll chloroplasts showed a measurable glycerolipid labelling (3-4%) from exogenous [14C]oleoyl-CoA in the presence of G3P (0.5 mM), although most of the radioactivity was found in the free fatty acid fraction (7—10%). Incorporation into diglycerides was increased two-fold under fatty acid synthesizing conditions in the medium and the resulting diglycerides were further galactosylated by UDP-galactose addition. The latter observations suggest, that even in spite o f the envelope imperme­ ability for physiological concentrations of long-chain acyl-CoA thioesters, fatty acid transfer from these substrates to typical chloroplast lipids cannot be totally excluded. 
  Reference    Z. Naturforsch. 38c, 399 (1983); received February 7 1983 
  Published    1983 
  Keywords    Chloroplast, Glycerol-3-Phosphate Uptake, Glycerolipid Synthesis 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0399.pdf 
 Identifier    ZNC-1983-38c-0399 
 Volume    38 
70Author    J.F T Spencer, D. M. Spencer, R. M. IllerRequires cookie*
 Title    Inability of Petite M utants of Industrial Yeasts to Utilize Various Sugars, and a Comparison with the Ability of the Parent Strains to Ferment the Same Sugars Microaerophilically  
 Abstract    A number of industrial strains of Saccharom yces cerevisiae were converted to the petite form and tested for the ability to utilize galactose, maltose, sucrose, a-methyl glucoside and raffinose. The parent strains all metabolized these sugars aerobically. Twelve of the petite forms did not utilize galactose, six failed to utilize maltose, 17 did not utilize a-methyl glucoside, and 18 did not utilize raffinose. The petites of two distiller's yeast strains did not utilize sucrose. The respiratory-competent parent strains nearly all fermented galactose, maltose, sucrose and raffinose, though 19 strains did not ferment a-methyl glucoside microaerophilically. Three strains did not ferment galactose, two fermented it only after several days adaptation, one did not ferment raffinose, and two did not ferment sucrose under microaerophilic conditions. Six respiratory-competent strains which did not utilize galactose when in the petite form fermented higher (10%) concentrations of glucose and maltose under microaerophilic conditions, but only three of these fermented galactose. The implications o f these findings for the use of such strains in industry are discussed briefly. 
  Reference    Z. Naturforsch. 38c, 405—407 (1983); received January 25 1983 
  Published    1983 
  Keywords    Petite Mutants, Sugars, Industrial Yeasts, Saccharom yces sp 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0405.pdf 
 Identifier    ZNC-1983-38c-0405 
 Volume    38 
71Author    W. N. Oé, H. U. SeitzRequires cookie*
 Title    Studies on the Regulatory Role of fra/is-Cinnamic Acid on the Activity of the Phenylalanine Ammonia-Lyase (PAL) in Suspension Cultures of Daucus carota L  
 Abstract    In vivo and in vitro experiments were performed in order to study the regulatory role of trans-cinnamic acid and its hydroxylated derivatives (p-coumaric acid, caffeic acid) on the deamina­ tion of phenylalanine catalyzed by PAL (EC 4.3.1.5). 7>arts-cinnamic acid inhibits growth and reduces the content of soluble proteins of anthocyanin-containing carrot cells grown in suspen­ sion. There is strong evidence from the polysomal patterns and from the effect of ?ra«5-cinnamic acid on protein synthesis in vitro that protein synthesis is inhibited. The kinetic data of PAL clearly demonstrate that /ra«s-cinnamic acid inhibits the enzyme by a noncompetitive mecha­ nism. On the contrary, L-a-aminooxy-/?-phenylpropionic acid (l-AOPP), a competitive inhibitor of PAL, does not affect protein metabolism. 
  Reference    Z. Naturforsch. 38c, 408 (1983); received January 24 1983 
  Published    1983 
  Keywords    Phenylalanine Ammonia-Lyase, Protein Metabolism, Regulation, /ra/js-Cinnamic Acid, Daucus carota, Suspension Culture 
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 Identifier    ZNC-1983-38c-0408 
 Volume    38 
72Author    Maurice Jay, Vincenzo De Luca, Ragai IbrahimRequires cookie*
 Title    Meta-Methylation o f Flavonol Rings A (8-) and B (3'-) Is Catalysed by Two Distinct O-Methyltransferases in Lotus corniculatus  
 Abstract    Two O-methyltransferases specific for flavonol rings A and B were isolated from young flower buds of Lotus corniculatus. They were partially purified by ammonium sulphate precipitation and successive chromatography on Sephadex G-100 and Polybuffer ion exchanger. One enzyme focused at pi 5.5 and catalysed the O-methylation of position 8 of flavonols with a pH optimum of 8.1. The other enzyme had a pi o f 5.1 and preferentially attacked position 3' at an optimum pH of 7.7. The methylated products o f both enzymes seem to contribute to the flower colour of Lotus and may be used as biochemical markers in genetic studies of this genus. 
  Reference    Z. Naturforsch. 38c, 413 (1983); received December 21 1982 
  Published    1983 
  Keywords    Lotus corniculatus, Leguminosae, O-Methyltransferase, Flavonols, 8-O-Methylation, 3'-0-Methylation 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0413.pdf 
 Identifier    ZNC-1983-38c-0413 
 Volume    38 
73Author    Joachim Vater, Thomas Gaudszun, Benita Lange, N. Azm, Iye Erdin, Johann SalnikowRequires cookie*
 Title    Characteristic Features of the Regulatory Functions of the D-Ribulose 1,5-Bisphosphate Carboxylase/O xygenase from Spinach  
 Abstract    Regulation of Rubisco, Anionic Modulators, Specificity and Mechanism o f Action o f Dianionic Effectors Catalysis and regulation o f C 0 2 fixation differ in a characteristic manner in their response to anionic modifiers and the polarity of the reaction medium. Monovalent inorganic anions inhibit catalysis and C 0 2-activation of the D-ribulose 1,5-bisphosphate carboxylase/oxygenase from spinach, whereas the activity and binding o f NADPH and effector sugar phosphates are affected only at appreciably higher concentrations. In contrast such modulators with a dianion structure stimulate C 0 2 fixation by an increase of the affinity o f the enzyme for the activator C 0 2 and stabilization of the reactive carbamate. Structure-activity studies revealed a broad specificity o f the enzyme for these regulatory effects. Essentially amino groups are involved in these processes. Certain organic solvents, as methanol or acetone, stimulate C 0 2 fixation by a similar modification of the C 0 2 activation centers, as induced by dianionic effectors. These results infer that such effects are due to a decrease of the polarity at the regulatory centers of the enzyme and a concomitant change of the pK of the active lysine responsible for the binding o f the activator C 0 2. A correlation of effector binding and activity demonstrates that already low, non-saturating concentrations o f such modifiers induce high activation levels of the carboxylase and prevent the dissociation o f the activated ternary complex. It is discussed that the central problem concerning the catalytical competence o f D-ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the presence of active site directed dianionic effectors can be solved kinetically. 
  Reference    Z. Naturforsch. 38c, 418 (1983); received January 27/March 17 1983 
  Published    1983 
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 Identifier    ZNC-1983-38c-0418 
 Volume    38 
74Author    Ahlert Schmidt, Ingrid ErdleRequires cookie*
 Title    A Cysteine Desulfhydrase Specific for D-Cysteine from the Green Alga Chlorella fusca  
 Abstract    A cysteine desulfhydrase was purified 110-fold from the green alga Chlorella using conven­ tional techniques. The isolated cysteine desulfhydrase was specific for D-cysteine having no activity towards L-cysteine. D -and L-cysteine desulfhydrase activities can be separated using DEAE-cellulose chromatography techniques. The isoelectric point o f this enzyme was deter­ mined to be around a pH o f 4.5 using a chromatofocussing column. The pH -optim um for the D-cysteine desulfhydrase was found to be in the range o f 8.5 to 9 and the apparent for D-cysteine was determined to 0.16 m M . The enzyme was active without addition o f metal ions and EDTA or citric acid did not inhibit this activity. 
  Reference    Z. Naturforsch. 38c, 428 (1983); received February 17 1983 
  Published    1983 
  Keywords    Chlorella, D-Cysteine, Cysteine Desulfhydrase 
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 Identifier    ZNC-1983-38c-0428 
 Volume    38 
75Author    Kassem AlefRequires cookie*
 Title    Regulation of Nitrogenase Activity in Rhodopseudomonas capsulata AD 2  
 Abstract    Nitrogenase, Regulation, Rhodopseudomonas capsulata A D 2 Regulation o f nitrogenase activity in Rhodopseudom onas capsulata A D 2 differs in several respects from other Rhodospirillaceae: 1) Nitrogenase activity in this strain grown under severe N -starvation was fully derepressed, but in contrast to other Rhodospirillaceae, it was inhibited by am m onia in vivo. 2) Nitrogenase in extracts o f glutamate grown cells was fully active and not further stim ulated by Mn2+. 3) Treatment o f N-starved or glutamate grown cells with am m onia before harvest did not cause inactivation o f nitrogenase in vitro. 
  Reference    Z. Naturforsch. 38c, 436—438 (1983); received March 14 1983 
  Published    1983 
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 Identifier    ZNC-1983-38c-0436 
 Volume    38 
76Author    Emilio Fernández, Jacobo CárdenasRequires cookie*
 Title    Nitrate Reductase from a Mutant Strain of Chlamydomonas reinhardii Incapable of Nitrate Assimilation  
 Abstract    Chlamydomonas reinhardii Mutants, Nitrate Reductase, N itrate R eductase Structure Nitrate reductase from mutant 305 o f Chlam ydom onas reinhardii has been purified about 90-fold and biochem ically characterized. The enzyme can use reduced flavins and viologens as electron donors to reduce nitrate but, unlike the nitrate reductase com plex from its parental wild strain, lacks NA D(P)H -nitrate reductase and N A D (P)H -cytochrom e c reductase activities, does not bind to Blue-Agarose or Blue-Sepharose and exhibits a significantly lower m olecular weight (177.000 vs. 241.000), whereas its kinetic characteristics and its sensitivity against several inhibitors and treatments are very similar to those o f the terminal nitrate reductase activity o f the wild strain complex. Spectral studies and antagonistic experim ents with tungstate show the presence o f cytochrome 6557 and molybdenum. These facts lead us to propose that nitrate reductase from mutant 305 has a protein deletion which affects the pyridine nucleotide binding region o f the diaphorase protein but without any effect on the terminal nitrate reductase activity. 
  Reference    Z. Naturforsch. 38c, 439 (1983); received February 21 1983 
  Published    1983 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0439.pdf 
 Identifier    ZNC-1983-38c-0439 
 Volume    38 
77Author    Ahlert Schmidt, Elisabeth KrämerRequires cookie*
 Title    A Membrane Bound Cysteine Oxydase from the Cyanobacterium Synechococcus 6301  
 Abstract    Membrane fractions o f the cyanobacterium Synechococcus 6301 obtained by french press treatment following sonication catalyzed an oxygen-dependent oxydation o f cysteine to cystine. For 1 0 2 consumed four cysteine were oxydized. O xygen uptake was com pletely inhibited by 1 mM KCN. Only D-and L-cysteine were active and partial activity was observed with DL-homocysteine and cysteamine. N o activity was found with glutathione, mercaptoethanol, thioglycerol, dithioerythritol, or N-acetyl-L-cysteine. Cysteines with a blocked acid group such as O-methyl-L-cysteine and O-ethyl-L-cysteine were oxydized rapidly by Synechococcus m em brane fractions. Rates o f about 200 (imol o f cysteine oxydized per mg chlorophyll and hour were measured. This cysteine respiration is discussed in relation to dark inactivation o f enzymes. 
  Reference    Z. Naturforsch. 38c, 446—450 (1983); received February 22 1983 
  Published    1983 
  Keywords    Cysteine Oxydation, Oxygen, Thiol Compounds, Synechococcus, Cyanobacteria 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0446.pdf 
 Identifier    ZNC-1983-38c-0446 
 Volume    38 
78Author    K. M. Uralidhar, G. Chaudhuri, J. Lippes, O. P. BahlRequires cookie*
 Title    A Specific and Sensitive Radioimmunoassay for Human Choriogonadotropin  
  Reference    Z. Naturforsch. 38c, 451 (1983) 
  Published    1983 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0451.pdf 
 Identifier    ZNC-1983-38c-0451 
 Volume    38 
79Author    SeymourSteven Brody, Lisbeth StelzigRequires cookie*
 Title    Effect of Pressure on the Absorption Spectra of Phycobiliprotein and Porphyridium cruentum  
 Abstract    Changes in the absorption spectra o f P. cruentum and phycobiliprotein are observed as a function o f hydrostatic pressure. With phycobiliprotein both in solution and in algae, increasing hydrostatic pressure results in bathochrom ic shifts o f the absorption m axim a. In addition, there is a splitting o f the absorption band o f phycoerythrin. When P. cruentum is subjected to 250 bars there are increases in absorption by chlorophyll (at 700 and 698 nm), phycocyanin (at 640 nm) and phycoerythrin (at 580 and 550 nm). W hen a cell free solution o f phycobiliprotein is subjected to 300 bars there are increases in absorption by phycoerythrin (at 570 and 550 nm) and phycocyanin (at 634 nm). 
  Reference    Z. Naturforsch. 38c, 458—460 (1983); received January 21 1983 
  Published    1983 
  Keywords    Pressure, Phycobiliprotein, Algae, Pressure Induced Change in Absorption Spectra 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0458.pdf 
 Identifier    ZNC-1983-38c-0458 
 Volume    38 
80Author    YousrY M Mostafa, Adam, S.M A D ZayedRequires cookie*
 Title      
 Abstract    Male mice were i.p. injected with two doses (5& 15 m g/kg body weight) o f [l-14C]ethyl-labelled chlorpyrifos. The radioactivity in liver, fat, kidney and urine was measured 6, 24, 48, and 192 h after treatment. Liver R N A and D N A were isolated and hydrolyzed and the bases separated by ion-exchange chromatography. R adioactivity resulting from incorporation and alkylation o f RNA and D N A was measured. Labelled 7-ethylguanine was found in R N A hydrolysate which am ounted 5.5 x 10-3 calculated as fraction o f the applied dose. In D N A hydrolysate [14C]7-ethylguanine was m issing and the major radioactivity was found in two unknown peaks, one o f which corresponds to 3 x 10-2 o f the applied dose. The results indicate that the extent o f alkylation obtained with clorpyrifos is high as com pared with other organophos-phates with methyl esters. 
  Reference    Z. Naturforsch. 38c, 461—464 (1983); received Septem ber 22 1982 
  Published    1983 
  Keywords    DN A, RNA, Alkylation, Insecticides, Chlorpyrifos 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0461.pdf 
 Identifier    ZNC-1983-38c-0461 
 Volume    38 
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