Results 131 to 140 of about 1,686 (162)

Quantification of corrinoids in methanogenic bacteria

Current Microbiology, 1980
Corrinoids in several diverse species of methanogens were quantified by a bioassay utilizingEscherichia coli 113-3, a corrinoid auxotroph. All five species examined contained >0.65 nmol corrinoid/mg dry cells when grown on H2/CO2 as carbon and energy source.
J. G. Zeikus, J. A. Krzycki
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Analysis of corrinoids in ovine tissues

Biomedical Chromatography, 2006
Corrinoids from various ovine tissue samples (liver, blood, small intestinal fluid and faeces) were analysed using a combination of high-performance liquid chromatography (HPLC) and a radioisotope dilution assay (RIDA) to estimate the distribution of corrinoids--the cobalamins hydroxocobalamin (OH-cbl), methylcobalamin (me-cbl) and 5 ...
J M Furlong, Tini M Gruner, Tini M Gruner, A R Sykes, R J Kelly   +4 more
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Zur Struktur rhodiumhaltiger Corrinoide [PDF]

Liebigs Annalen der Chemie, 1980
AbstractDurch Umsetzung von Hydrogenobyrinsäure‐a,c‐diamid (1) mit [Rh(CO)2Cl]2 in Eisessig/Ethanol (1:1; Vol.: Vol.) erhält man als Hauptprodukt Rhodibyrinsäure‐a,c‐diamid 2. Die Identität von 2 wird durch Röntgenstrukturanalyse bestätigt. Veresterung von 2 mit Methanol/Schwefelsäure führt neben Rhodibyrinsäure‐pentamethylester‐a,c‐diamid 3a zu den ...
William S. Sheldrick, Ludger Ernst, Volker B. Koppenhagen, Bernd Dresow, Gerhard Schlingmann   +4 more
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Cobalt and Corrinoid Transport and Biochemistry

2012
In this chapter, we focus on the biochemistry of non-corrin cobalt and on a subset of corrinoid-containing enzymes. We review the import of cobalt in prokaryotes and discuss two members of the non-corrin cobalt-dependent enzymes, nitrile hydratase and methionine aminopeptidase.
Valentin Cracan, Ruma Banerjee
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Corrinoid and thiol dependent threonine decarboxylation

Biochemical and Biophysical Research Communications, 1976
Summary A novel system for the decarboxylation of L-threonine requiring the presence of certain aquocorrinoids, preferably diaquocobyric acid, and of a thiol is described. The reaction shows a marked optimum at a pH value of about 8. Other L-amino acids, with the exception of L-serine, are much less reactive. Optical data point to a ligand attachment
Susan H. Ford, Herbert C. Friedmann
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The inorganic chemistry of the cobalt corrinoids – an update

Journal of Inorganic Biochemistry, 2023
The inorganic chemistry of the cobalt corrinoids, derivatives of vitamin B12, is reviewed, with particular emphasis on equilibrium constants for, and kinetics of, their axial ligand substitution reactions. The role the corrin ligand plays in controlling and modifying the properties of the metal ion is emphasised. Other aspects of the chemistry of these
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Application of difference spectra of corrinoids to their determination

Analytical Biochemistry, 1969
Abstract Marked absorbance differences were observed between the monocyano and dicyano forms at 358 and 370 mμ in the case of complete corrinoids, and at 354 and 368 mμ in the case of incomplete corrinoids. Approximately equal absorbance difference coefficients were derived from the absorbance differences at the respective two wavelengths for the ...
Hideki Narahara, Tadashi Kamikubo, Tadashi Shimizu   +2 more
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Cobalt-free Corrinoids as Vitamin B12 Antagonists

Nature, 1966
Abstract The anti-vitamin B12 properties of four descobalto-corrins isolated from Chromatium cells were compared with vitamin B12-anilide, vitamin B12-monocarboxylic acid, cobinamide, and Friedrich's C′3-2-methyl-2-aminopropanol(1)-vitamin B12 (compound S-102).
John I. Toohey, John I. Toohey, D. Perlman, D. Perlman   +3 more
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Microbial degradation of corrinoids

Archives of Biochemistry and Biophysics, 1965
Abstract Three yellow pigment fractions produced from vitamin B12 by Pseudomonas rubescens cultures are shown by several methods to contain cyanide and a 5,6-dimethylbenzimidazole moiety. Spectral examination shows that brief exposure of each pigment to light causes a reversible cleavage of cyanide, and that prolonged exposure causes a slow ...
W. M. Scott, J. J. Pfiffner, J. B. Hufham, R. C. Burgus   +3 more
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NMR-restrained molecular modeling of cobalt corrinoids: cyanocobalamin (vitamin B12) and methylcobalt corrinoids

Journal of Molecular Structure: THEOCHEM, 1998
Abstract NMR-restrained molecular dynamics (MD) and simulated annealing (SA) calculations have been performed on cyanocobalamin (CNCbl, vitamin B 12 ), and three methylcobalt corrinoids, the coenzymatically active methylcobalamin (CH 3 Cbl), and two analogs of its base-off species, methylcobinamide (CH 3 Cbi + ), which lacks an axial nucleotide, and ...
Xiang Zou, Kenneth L. Brown, Helder M. Marques   +2 more
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