High warfarin sensitivity in carriers of CYP2C9*35 is determined by the impaired interaction with P450 oxidoreductase

摘要: Cytochrome P450 2C9 (CYP2C9) metabolizes many clinically important drugs including warfarin and diclofenac. We have recently reported a new allelic variant, CYP2C9*35, found in hypersensitive patient with Arg125Leu Arg144Cys mutations. Here, we investigated the molecular basis for functional consequences of these polymorphic changes. CYP2C9.1 CYP2C9-Arg144Cys expressed human embryonic kidney 293 cells effectively metabolized both S-warfarin diclofenac NADPH-dependent reactions, whereas CYP2C9-Arg125Leu or CYP2C9.35 were catalytically silent. However, when NADPH was replaced by direct electron donor to CYPs, cumene hydroperoxide, hereby bypassing CYP oxidoreductase (POR), all variant enzymes active, indicating unproductive interactions between POR. In silico analysis revealed decrease electrostatic potential CYP2C9-Arg125Leu-POR interacting surface loss stabilizing salt bridges proteins. conclusion, our data strongly suggest that mutation prevents CYP2C9-POR resulting absence CYP2C9-catalyzed activity vivo, thus influencing sensitivity carriers this allele.