Reaction of Pyridoxamine-Pyruvate Transaminase with Sulfhydryl Reagents
نویسندگان
چکیده
منابع مشابه
Reaction 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 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 کاملThe 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 کاملPyridoxamine-pyruvate transaminase. 2. Temperature-jump and stopped-flow kinetic investigation of the rates and mechanism of the reaction of 5'-deoxypyridoxal with the enzyme.
The kinetics and mechanism of enzymatic Schiff base formation and hydrolysis were investigated by rapid reactions measurements of 5'-deoxypyridoxal with pyridoxamine-pyruvate transaminase (EC 2.6.1.30). The dissociation rate constant, koff, was determined as a function of pH over the range pH 7-9 by a stopped-flow method in which the nascent free enzyme was trapped by the potent bisubstrate ana...
متن کاملNonequivalence of the two subunits of horse erythrocyte glutathione transferase in their reaction with sulfhydryl reagents.
Glutathione transferase (EC 2.5.1.18) from horse erythrocytes has been purified and some molecular and kinetic properties have been investigated. It appears to be a dimeric protein composed of subunits of about 23 kDa, indistinguishable either in sodium dodecyl sulfate or in urea electrophoresis. Amino acid composition, substrate specificities, sensitivity to inhibitors, CD spectra, and immunol...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 1965
ISSN: 0021-9258
DOI: 10.1016/s0021-9258(18)97285-6