Kim, BR Oh, HS Kim, DH 2024-01-21T18:01:27Z 2024-01-21T18:01:27Z 2021-09-01 1997-11 1039-9712 https://pubs.kist.re.kr/handle/201004/143540 Human cytochrome P450 (P450) 3A is known to be involved in the formation of both aflatoxin B-1-exo-8,9-epoxide (exo-epoxidation) and aflatoxin Q(1)(3 alpha-hydroxylation). Gestodene, a known inactivator of P450 3A4, inhibited the formation of AFB(1) metabolites in a variety of ways depending on the incubation condition. Preincubation of gestodene with human liver microsomes prior to the addition of AFB(1) inhibited both exo-epoxidation and 3 alpha-hydroxylation whereas simultaneous incubation of gestodene with AFB(1) only inhibited 3 alpha-hydroxylation. These results suggest that two independent substrate binding sites exist in P450 3A4, and AFB(1) binds to both of the binding sites. Gestodene selectively binds to one of the binding sites leading to the formation of AFQ(1), whereas it does not affect the formation of exo-epoxide via the other binding site. English ACADEMIC PRESS AUST HUMAN CYTOCHROME-P450 3A4 ALFENTANIL METABOLISM RAT-LIVER CYTOCHROME-P-450-IIIA4 7,8-BENZOFLAVONE IDENTIFICATION ACTIVATION BINDING Differential inhibition of aflatoxin B-1 oxidation by gestodene action on human liver microsomes Article 1 BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL, v.43, no.4, pp.839 - 846 BIOCHEMISTRY AND MOLECULAR BIOLOGY INTERNATIONAL 43 4 839 846 scie scopus 000073191200016 2-s2.0-0031394858 Biochemistry & Molecular Biology Biochemistry & Molecular Biology Article HUMAN CYTOCHROME-P450 3A4 ALFENTANIL METABOLISM RAT-LIVER CYTOCHROME-P-450-IIIA4 7,8-BENZOFLAVONE IDENTIFICATION ACTIVATION BINDING aflatoxin B-1 gestodene P450 3A4 inhibition