Binding of bufuralol, dextromethorphan, and 3,4-methylenedioxymethylamphetamine to wild-type and F120A mutant cytochrome P450 2D6 studied by resonance Raman spectroscopy.

Alois Bonifacio, Peter H J Keizers, Jan N M Commandeur, Nico P E Vermeulen, Bruno Robert, Cees Gooijer, Gert van der Zwan

Index: Biochem. Biophys. Res. Commun. 343(3) , 772-9, (2006)

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Abstract

Cytochrome P450 2D6 (CYP2D6) is one of the most important drug-metabolizing enzymes in humans. Resonance Raman data, reported for the first time for CYP2D6, show that the CYP2D6 heme is found to be in a six-coordinated low-spin state in the absence of substrates, and it is perturbed to different extents by bufuralol, dextromethorphan, and 3,4-methylenedioxymethylamphetamine (MDMA). Dextromethorphan and MDMA induce in CYP2D6 a significant amount of five-coordinated high-spin heme species and reduce the polarity of its heme-pocket, whereas bufuralol does not. Spectra of the F120A mutant CYP2D6 suggest that Phe120 is involved in substrate-binding of dextromethorphan and MDMA, being responsible for the spectral differences observed between these two compounds and bufuralol. These differences could be explained postulating a different substrate mobility for each compound in the CYP2D6 active site, consistently with the role previously suggested for Phe120 in binding dextromethorphan and MDMA.