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  • 1
    Electronic Resource
    Electronic Resource
    Studies on the inactivation of the flavoproteind-amino acid oxidase fromTrigonopsis variabilis (1996)
    Springer
    Applied microbiology and biotechnology 45 (1996), S. 458-464 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Inactivation ofd-amino acid oxidase occured by different mechanisms. The enzyme showed a rapid loss of activity in the presence of micromolar amounts of Cu2+ and Hg2+. It was also sensitive to oxidative inactivation by Fe2+ and H2O2 when both reagents were added in millimolar amounts. When oxidatively inactivatedd-amino acid oxidase and a corresponding non-treated control were modified with the sulfhydryl-modifying, fluorescent reagent monobromobimane and subsequently digested with endoproteinase Glu-C, Cys-298 was identified to be a target for oxidative modification according to differences in the known peptide profile of fluorescence intensity. Another reason for the observed loss of enzyme activity in crude extracts was the specific proteolytic digestion ofd-amino acid oxidase, which was dependent on the growth phase of the cells used. This cleavage was catalyzed by a serine-type proteinase and was the introductory step for the further complete degradation of the enzyme. In addition, a coenriched 50-kDa protein, identified as NADPH-specific glutamate dehydrogenase, significantly decreased the stability of thed-amino acid oxidase activity. Treatment of apo-d-amino acid oxidase fromT. variabilis with monobromobimane resulted in a significantly increased fluorescence of two peptides, neither of which contained any cysteine residue. Thus, an involvement of cysteine residues in binding the FAD coenzyme should be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00578456
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  • 2
    Electronic Resource
    Electronic Resource
    Studies on the inactivation of the flavoprotein D-amino acid oxidase from Trigonopsis variabilis (1996)
    Springer
    Applied microbiology and biotechnology 45 (1996), S. 458-464 
    Details
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  Inactivation of D-amino acid oxidase occurred by different mechanisms. The enzyme showed a rapid loss of activity in the presence of micromolar amounts of Cu2+ and Hg2+. It was also sensitive to oxidative inactivation by Fe2+ and H2O2 when both reagents were added in millimolar amounts. When oxidatively inactivated D-amino acid oxidase and a corresponding non-treated control were modified with the sulfhydryl-modifying, fluorescent reagent monobromobimane and subsequently digested with endoproteinase Glu-C, Cys-298 was identified to be a target for oxidative modification according to differences in the known peptide profile of fluorescence intensity. Another reason for the observed loss of enzyme activity in crude extracts was the specific proteolytic digestion of D-amino acid oxidase, which was dependent on the growth phase of the cells used. This cleavage was catalyzed by a serine-type proteinase and was the introductory step for the further complete degradation of the enzyme. In addition, a coenriched 50-kDa protein, identified as NADPH-specific glutamate dehydrogenase, significantly decreased the stability of the D-amino acid oxidase activity. Treatment of apo-D-amino acid oxidase from T. variabilis with monobromobimane resulted in a significantly increased fluorescence of two peptides, neither of which contained any cysteine residue. Thus, an involvement of cysteine residues in binding the FAD coenzyme should be excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00578456
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  • 3
    Electronic Resource
    Electronic Resource
    Morpholine-induced formation of l-alanine dehydrogenase activity in Mycobacterium strain HE5 (1999)
    Springer
    Archives of microbiology 171 (1999), S. 417-423 
    Details
    ISSN: 1432-072X
    Keywords: Key words Alanine dehydrogenase ; Ammonia ; assimilation ; Mycobacterium ; Morpholine degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract An NAD-dependent, morpholine-stimulated l-alanine dehydrogenase activity was detected in crude extracts from morpholine-, pyrrolidine-, and piperidine-grown cells of Mycobacterium strain HE5. Addition of morpholine to the assay mixture resulted in an up to 4.6-fold increase of l-alanine dehydrogenase activity when l-alanine was supplied at suboptimal concentration. l-Alanine dehydrogenase was purified to near homogeneity using a four-step purification procedure. The native enzyme had a molecular mass of 160 kDa and contained one type of subunit with a molecular mass of 41 kDa, indicating a tetrameric structure. The sequence of 30 N-terminal amino acids was determined and showed a similarity of up to 81% to that of various alanine dehydrogenases. The pH optimum for the oxidative deamination of l-alanine, the only amino acid converted by the enzyme, was determined to be pH 10.1, and apparent K m values for l-alanine and NAD were 1.0 and 0.2 mM, respectively. K m values of 0.6, 0.02, and 72 mM for pyruvate, NADH, and NH4 +, respectively, were estimated at pH 8.7 for the reductive amination reaction.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002030050728
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  • 4
    Electronic Resource
    Electronic Resource
    Selenium requirement for active xanthine dehydrogenase from Clostridium acidiurici and Clostridium cylindrosporum (1979)
    Springer
    Archives of microbiology 121 (1979), S. 255-260 
    Details
    ISSN: 1432-072X
    Keywords: Purine fermentation ; Xanthine dehydrogenase ; Selenium ; Tungsten ; Molybdenum ; Clostridium acidiurici ; Clostridium cylindrosporum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The xanthine dehydrogenase of Clostridium acidiurici and C. cylindrosporum was assayed with methyl viologen as acceptor. In C. acidiurici the basal activity level was about 0.3 μmol/min x mg of protein. Cells grown on uric acid in the presence of 10-7 M selenite showed a 14-fold increase in xanthine dehydrogenase activity, which decreased with higher selenite concentrations (10-5 M). The supplementation with 10-7 M molybdate or tungstate was without effect. High concentrations of tungstate decreased the xanthine dehydrogenase if selenite was also present. In comparison, high concentrations of molybdate affected only a small decrease in activity level at the optimal concentration for selenite and relieved to some degree the inhibitory effect of 10-5 M selenite. With hypoxanthine and xanthine as substrates for growth again only the addition of selenite was necessary to show a similar increase in xanthine dehydrogenase activity. C. acidiurici could be grown in a mineral medium. Both xanthine dehydrogenase and formate dehydrogenase exhibited the highest level of activity if selenite and tungstate were present in that medium. In C. cylindrosporum the basal activity level of xanthine dehydrogenase was about 0.95 μmol/min x mg of protein. The addition of 10-7 M selenite to the growth medium increased the activity level about 3-fold, but the highest level (3.7 U/mg) was reached if 10-7 M molybdate was also added. The presence of tungstate resulted in a decreased enzyme activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00425064
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  • 5
    Electronic Resource
    Electronic Resource
    Pathways and regulation of N2, ammonium and glutamate assimilation by Clostridium formicoaceticum (1983)
    Springer
    Archives of microbiology 134 (1983), S. 167-169 
    Details
    ISSN: 1432-072X
    Keywords: Nitrogenase ; Glutamine synthetase ; Glutamate synthase ; Glutamate dehydrogenase ; Asparagine synthetase ; Alanine dehydrogenase ; β-Methylaspartase ; Clostridium formicoaceticum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clostridium formicoaceticum possesses the following enzymes for the assimilation of N2 and NH 4 + : nitrogenase, glutamine synthetase, NADH- and NADPH-dependent glutamate synthase, NADH- and NADPH-dependent glutamate dehydrogenase, NADPH-dependent alamine dehydrogenase, and NH 4 + -dependent asparagine synthetase. Nitrogenase and glutamine synthetase are repressed and alanine dehydrogenase is induced by NH 4 + , while the synthesis of the other enzymes is not influenced by the extracellular NH 4 + level. Glutamate is degraded via glutamate mutase and β-methylaspartase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00407953
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  • 6
    Electronic Resource
    Electronic Resource
    Peripheral localization of the dihydrolipoamide dehydrogenase in the purinolytic anaerobe Clostridium cylindrosporum (1991)
    Springer
    Archives of microbiology 155 (1991), S. 412-414 
    Details
    ISSN: 1432-072X
    Keywords: Clostridium cylindrosporum ; Dihydrolipoamide dehydrogenase ; Glycine decarboxylase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Immunocytochemical localization experiments were performed with antibodies raised against the dihydrolipoamide dehydrogenase protein (P3) of the glycine decarboxylase complex from clostridium cylindrosporum using the low-temperature procedure and protein A-gold technique. An association with the cytoplasmic membrane was indicated to about 65 (±10) % when cells were analyzed from the logarithmic growth phase. The unusual peripheral localization is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00243464
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  • 7
    Electronic Resource
    Electronic Resource
    Fumarate reductase of Clostridium formicoaceticum (1978)
    Springer
    Archives of microbiology 119 (1978), S. 7-11 
    Details
    ISSN: 1432-072X
    Keywords: Clostridium formicoaceticum ; Fumarate reductase ; Peripheral enzyme ; Membrane protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract When Clostridium formicoaceticum was grown on fumarate or l-malate crude cell extracts contained a high fumarate reductase activity. Using reduced methyl viologen as electron donor the specific activity amounted to 2–3.5 U per mg of protein. Reduced benzyl viologen, FMNH2 and NADH could also serve as electron donors but the specific activities were much lower. The NADH-dependent activity was strictly membrane-bound and rather labile. Its specific activity did not exceed 0.08 U per mg of particle protein. Fumarate reductase activity was also found in cells of C. formicoaceticum grown on fructose, gluconate, glutamate and some other substrates. The methyl viologen-dependent fumarate reductase activity could almost completely be measured with intact cells whereas only about 25% of the cytoplasmic acetate kinase activity was detected with cell suspensions. The preparation of spheroplasts from cells of C. formicoaceticum in 20 mM HEPES-KOH buffer containing 0.6 M sucrose and 1 mM dithioerythritol resulted in the specific release of 88% of the fumarate reductase activity into the spheroplast medium. Only small amounts of the cytoplasmic proteins malic enzyme and acetate kinase were released during this procedure. These results indicate a peripheral location of the fumarate reductase of C. formicoaceticum on the membrane.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00407920
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  • 8
    Electronic Resource
    Electronic Resource
    Eubacterium angustum sp. nov., a Gram-positive anaerobic, non-sporeforming, obligate purine fermenting organism (1984)
    Springer
    Archives of microbiology 140 (1984), S. 2-8 
    Details
    ISSN: 1432-072X
    Keywords: Eubacterium angustum ; Purine metabolism ; Xanthine dehydrogenase ; Selenium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A strictly anaerobic, uric acid, xanthine, and guanine fermenting bacterium was isolated from sewage sludge requiring thiamine as a vitamin. Acetate, formate, ammonia and CO2 were products. Cells were Gram-positive, straight rods, 3 to 6.5 μm long and 1.1 to 1.5 μm wide. They were non-motile, however, possessed flagella. Spore formation could not be obtained. The guanine-plus-cytosine content (G+C) of its deoxyribonucleic acid was 40.3 mol%. Based on these features, the organism belongs to the genus Eubacterium. Due to its restricted substrate spectrum and its inability to utilize arginine or to form cytochromes like E. lentum, this organism did not resemble any of the previously described species of Eubacterium. Therefore, it is proposed to form a new species Eubacterium angustum sp. nov.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00409763
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  • 9
    Electronic Resource
    Electronic Resource
    Accumulation and incorporation of 185W-tungsten into proteins of Clostridium acidiurici and Clostridium cylindrosporum (1987)
    Springer
    Archives of microbiology 147 (1987), S. 295-299 
    Details
    ISSN: 1432-072X
    Keywords: Clostridium acidiurici ; Clostridium cylindrosporum ; Tungsten uptake ; Molybdate antagonism ; Formate dehydrogenase ; Tungsten-binding-storage protein
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Uptake of tungstate by growing cells was unaffected by the presence of molybdate in Clostridium cylindrosporum, whereas in C. acidiurici the accumulation was decreased by molybdate at 10-6 mol/l tungstate and higher concentrations. The labelling pattern of soluble proteins by 185W-tungsten indicated after gel chromatography the presence of three different tungstoproteins in both bacteria. Formate dehydrogenase activity always eluted at a maximum of tungsten labelling. The incorporation of tungsten into formate dehydrogenase containing fractions and a possible tungsten-binding-storage protein was independent of the presence of excess molydate pointing to a genuine role for tungstate in these bacteria.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00463491
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  • 10
    Electronic Resource
    Electronic Resource
    Comparative studies on physiology and taxonomy of obligately purinolytic clostridia (1984)
    Springer
    Archives of microbiology 138 (1984), S. 345-353 
    Details
    ISSN: 1432-072X
    Keywords: Clostridium acidiurici ; Clostridium cylindrosporum ; Clostridium purinolyticum ; Purine metabolism ; Selenite ; Antibiogram ; DNA homology ; Taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Eleven strains of obligately purinolytic clostridia have been studied with respect to their assignment to the three type strains of Clostridium acidiurici, C. cylindrosporum, and C. purinolyticum. DNA/DNA-hybridization proved to be the method of choice for differentiation whereas phenotypic characteristics such as spore morphology, substrate spectra, nutritional requirements, product formation, and sensitivity against various antibiotics did not allow unequivocal identification. All strains depended on selenite for growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00410902
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