The pyridoxal-binding site in pyridoxamine-pyruvate transaminase
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چکیده
منابع مشابه
The pyridoxal-binding site in pyridoxamine-pyruvate transaminase.
The enzyme-substrate complex formed between pyridoxamine-pyruvate transaminase (EC 2.6.1.30) and pyridoxal was reduced with NaBH4. After carboxymethylation and tryptic digestion, pyridoxyl-lysine-containing peptides were isolated by a combination of Sephadex and Dowex 50 chromatography. Analysis of these peptides shows the structure around the pyridoxal-binding lysine residues to be Ala-Asp-Ile...
متن کاملInteraction of Pyridoxamine-pyruvate Transaminase with Carbonyl Derivatives of Pyridoxal.
on pyridoxine or pyridoxamine as a sole source of carbon and nitrogen (1, 2). This transaminase contains no pyridoxal phosphate, and hence provides a simpler system for mechanistic studies than do the more complex, pyridoxal phosphate-containing transaminases. The enzyme binds pyridoxamine and pyridoxal with almost equal avidity; the latter is bound in part by an azomethine Iinkage to the e-ami...
متن کاملReaction of Pyridoxamine - Pyruvate Transaminase Sulfhydryl Reagents
Wherever the point has been examined (e.g. References l-6), pyridoxal phosphate enzymes have been found to require free sulfhydryl groups for activity. The functional role played by these groups, however, has not been clear. In glutamate-oxaloacetate transaminase, which has been studied most extensively, no spectrophotometric or enzymatic evidence for their participation in coenzyme binding was...
متن کاملPyridoxamine-pyruvate transaminase. 1. Determination of the active site stoichiometry and the pH dependence of the dissociation constant for 5'-deoxypyridoxal.
Spectrophotometric titration of pyridoxamine-pyruvate transaminase (EC 2.6.1.30) with pyridoxal at pH 7.15 gives four equivalent binding sites per tetramer. The pH dependence of the equilibrium constant for the association of 5'-deoxypyridoxal with the active site lysine residue was determined spectrophotometrically. These dissociation constants increase with increasing pH over the range pH 7.5...
متن کاملMolecular cloning, expression and characterization of pyridoxamine-pyruvate aminotransferase.
Pyridoxamine-pyruvate aminotransferase is a PLP (pyridoxal 5'-phosphate) (a coenzyme form of vitamin B6)-independent aminotransferase which catalyses a reversible transamination reaction between pyridoxamine and pyruvate to form pyridoxal and L-alanine. The gene encoding the enzyme has been identified, cloned and overexpressed for the first time. The mlr6806 gene on the chromosome of a symbioti...
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ژورنال
عنوان ژورنال: Biochemical Journal
سال: 1978
ISSN: 0264-6021
DOI: 10.1042/bj1690429