Effects of Intermediate Metabolites of 37 Xenobiotics on the Catalytic Activities of Reconstituted Cytochrome P-450IIB1 and P-450IA1 Enzyme Systems
Effects of Intermediate Metabolites of 37 Xenobiotics on the Catalytic Activities of Reconstituted Cytochrome P-450IIB1 and P-450IA1 Enzyme Systems作者机构:InstitueofOccupationalMedicineChineseAcademyofPreventiveMedicineBeijing100050 InstitueofOccupation
出 版 物:《Biomedical and Environmental Sciences》 (生物医学与环境科学(英文版))
年 卷 期:1993年第6卷第1期
页 面:8-26页
核心收录:
学科分类:0710[理学-生物学] 100405[医学-卫生毒理学] 0830[工学-环境科学与工程(可授工学、理学、农学学位)] 071010[理学-生物化学与分子生物学] 1004[医学-公共卫生与预防医学(可授医学、理学学位)] 081704[工学-应用化学] 1001[医学-基础医学(可授医学、理学学位)] 07[理学] 08[工学] 0817[工学-化学工程与技术] 10[医学]
主 题:rate Effects of Intermediate Metabolites of 37 Xenobiotics on the Catalytic Activities of Reconstituted Cytochrome P-450IIB1 and P-450IA1 Enzyme Systems IA
摘 要:Direct effects of intermediate metabolites of 37 different xenobiotics on the catalytic activities of both reconstituted cytochrome P-450IIB1 and P-450IA1 enzyme systems were studied by determination of NADPH oxidation at various intervals after initiation of the reaction. The results showed that cytochrome P-450IIB1 isozyme was much more likely than cytochrome P-450IA1 isozyme to be attacked by the reactive intermediates formed by some xenobiotics with smaller molecular weight and lose its catalytic activities. These xenobiotics were carbon tetrachloride, chloroform, carbon disulfide, benzene, parathion, methylparathion, methyldursban and dimethylnitrosamine. In contrast, however, steadily increasing metabolic activities were observed towards benzo(a)pyrene, 3-methyl-cholanthrene and polychlorinated biphenyls in reconstituted cytochrome P-450IA1 enzyme system as the reaction time prolonged within 4 min. The method discussed in this paper could be used as a simple and convenient way to observe directly the autocatalytic destruction of P-450 enzymes by some chemical agents.