title: Substrate Selectivities and Catalytic Activities of Marmoset Liver Cytochrome P450 2A6 Differed from Those of Human P450 2A6.
abstract: The common marmoset (Callithrix jacchus), a New World primate species, is potentially a useful animal model for preclinical studies in drug development. However, cytochrome P450 (P450) enzymes have not been fully identified and characterized in marmosets. In this study, we identified P450 2A6 cDNA with the sequence highly identical (91-94%) to human P450 2A6, 2A7, and 2A13 cDNA and cynomolgus monkey P450 2A23, 2A24, and 2A26 cDNA. Among the tissue types examined, marmoset P450 2A6 mRNA was most abundantly expressed in livers where P450 2A6 protein was also detected by immunoblotting. Phylogenetic analysis showed that marmoset P450 2A6 was more closely clustered with human and cynomolgus monkey P450 2As than P450 2As of dog, rat, and mouse (the species also used in drug metabolism). Marmoset P450 2A6 heterologously expressed in Escherichia coli membranes efficiently catalyzed 7-ethoxycoumarin O-deethylation, similar to human P450 2A6 and 2A13 and cynomolgus monkey P450 2A23, 2A24, and 2A26, but much less effectively coumarin 7-hydroxylation, showing some difference as well. Interestingly, marmoset P450 2A6 and cynomolgus monkey P450 2A23 catalyzed phenacetin O-deethylation, which is catalyzed by human P450 1A2 and 2A13, but not by P450 2A6. Marmoset P450 2A6 also exhibited catalytic activity toward testosterone by the multiple sites, but not rat P450 2A-specific testosterone 7α-hydroxylation activity. These results indicated that marmoset P450 2A6 had functional characteristics different from those of human and cynomolgus monkey P450 2As in terms of partially different substrate specificities and catalytic activities, indicating its importance of further studies for P450 2A-dependent drug metabolism in marmosets.
authors: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Kainan, Wakayama, Japan (Y.U.); Department of Applied Developmental Biology, Central Institute for Experimental Animals, Kawasaki, Japan (T.I., E.S.); and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.).
authors: Shotaro
authors: S
authors: Uehara
authors: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Kainan, Wakayama, Japan (Y.U.); Department of Applied Developmental Biology, Central Institute for Experimental Animals, Kawasaki, Japan (T.I., E.S.); and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.).
authors: Yasuhiro
authors: Y
authors: Uno
authors: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Kainan, Wakayama, Japan (Y.U.); Department of Applied Developmental Biology, Central Institute for Experimental Animals, Kawasaki, Japan (T.I., E.S.); and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.).
authors: Takashi
authors: T
authors: Inoue
authors: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Kainan, Wakayama, Japan (Y.U.); Department of Applied Developmental Biology, Central Institute for Experimental Animals, Kawasaki, Japan (T.I., E.S.); and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.).
authors: Erika
authors: E
authors: Sasaki
authors: Laboratory of Drug Metabolism and Pharmacokinetics, Showa Pharmaceutical University, Machida, Tokyo, Japan (S.U., H.Y.); Pharmacokinetics and Bioanalysis Center, Shin Nippon Biomedical Laboratories, Kainan, Wakayama, Japan (Y.U.); Department of Applied Developmental Biology, Central Institute for Experimental Animals, Kawasaki, Japan (T.I., E.S.); and Keio Advanced Research Center, Keio University, Minato-ku, Tokyo, Japan (E.S.) hyamazak@ac.shoyaku.ac.jp.
authors: Hiroshi
authors: H
authors: Yamazaki
mesh_terms: D015660:7-Alkoxycoumarin O-Dealkylase / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002144:Callithrix / Q000378:metabolism*; D002384:Catalysis; D019388:Cytochrome P-450 CYP1A2 / Q000378:metabolism; D065637:Cytochrome P-450 CYP2A6 / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D005091:Exons; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007700:Kinetics; D008969:Molecular Sequence Data; D013045:Species Specificity; D013379:Substrate Specificity
chemical_list: D015660:7-Alkoxycoumarin O-Dealkylase; D001189:Aryl Hydrocarbon Hydroxylases; C414206:CYP2A13 protein, human; C585710:CYP2A6 protein, human; D019388:Cytochrome P-450 CYP1A2; D065637:Cytochrome P-450 CYP2A6