Correlation of human cytochrome P4502C substrate specificities with primary structure : warfarin as a probe

摘要: The regio- and stereoselectivity of warfarin metabolism have been used to assess structure-function relationships human P4502C subfamily members. Metabolism was investigated using a yeast cDNA expression system in which full length cDNAs for P4502C8, -2C9 (alleles Arg144 Tyr358 Ile359 Gly417 Leu359 Gly417), -2C18 Thr385 Met385), -2C19 were expressed. Additionally, two mutations reported other P4502C9/2C10 alleles individually introduced into P4502C9 by site-directed mutagenesis, yield Cys144 Gly417, Asp417, Cys358 expressed yeast; their ability metabolize then studied. Warfarin purified preparations allele its mutant also reconstituted systems. Both P4502C18 regioselective 4'-hydroxywarfarin, without any significant stereoselectivity. metabolized at the 6-position, but lesser extent, this site stereoselective (R)-warfarin. P4502C8 7-position stereospecific It extent 4'-position, P4502C19 6- 8-hydroxywarfarin highly conservative mutation profoundly altered metabolism, from 7-hydroxywarfarin, with stereospecificity (S)-warfarin, (R)-warfarin, confirmed recombinant enzymes. In contrast, individual Cys, Asp did not markedly affect or although overall rates apparently increased these changes. We conclude that residue 359 is substrate binding P4502C9, whereas residues 144, 358, 417, 385 P4502C18, are not.