Chemical modification of histidine residue in substrate-binding domain of carbonyl reductase from rabbit kidney.
Carbonyl reductase from rabbit kidney was rapidly inactivated by diethylpyrocarbonate (DEPC). A similar inactivation was observed in photooxidation of the enzyme by methylene blue. The inactivation by DEPC was time- and concentration-dependent and followed pseudo-first-order kinetics. The results obtained from the inactivation kinetics and the protective effect of 4-acetylpyridine (4-AP) with NADP+ against the inactivation led to the idea that one essential amino acid is located in substrate-binding domain of the enzyme. The treatment of the enzyme with DEPC formed N-carbethoxyhistidine. Judging from the effect of 4-AP with NADP+ on the formation of N-carbethoxyhistidine, it is concluded that one histidine residue is located in substrate-binding domain of the enzyme. Furthermore, whether one essential amino acid inactivated by DEPC corresponds to one histidine residue modified with DEPC is discussed.
Imamura
Y
Y
Faculty of Pharmaceutical Sciences, Kumamoto University, Japan.
Higuchi
T
T
Otagiri
M
M
D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D004047:Diethyl Pyrocarbonate / Q000494:pharmacology; D006639:Histidine / Q000737:chemistry*; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D009249:NADP / Q000494:pharmacology; D010084:Oxidation-Reduction; D011725:Pyridines / Q000494:pharmacology; D011817:Rabbits; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D011725:Pyridines; D006639:Histidine; D009249:NADP; D000429:Alcohol Oxidoreductases; C055538:4-acetylpyridine; D004047:Diethyl Pyrocarbonate