Active-Site Topologies of Human CYP2D6 and Its Aspartate-301 → Glutamate, Asparagine, and Glycine Mutants

• Published in: Archives of biochemistry and biophysics 1996-07, Vol.331 (1), p.134-140
• Main Authors: Mackman, Richard, Tschirret-Guth, Richard A., Smith, Gillian, Hayhurst, Graham P., Ellis, S.Wynne, Lennard, Martin S., Tucker, Geoffrey T., Wolf, C.Roland, Ortiz de Montellano, Paul R.
• Format: Article
• Language: English
• Subjects: Asparagine; Aspartic Acid; Binding Sites; Cytochrome P-450 CYP2D6; Cytochrome P-450 Enzyme System - chemistry; Cytochrome P-450 Enzyme System - genetics; Electrochemistry; Glutamic Acid; Glycine; Humans; Hydrazines - chemistry; Imines - chemistry; Mixed Function Oxygenases - chemistry; Mixed Function Oxygenases - genetics; Models, Molecular; Molecular Structure; Mutation; Protoporphyrins - chemistry; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae - genetics; Structure-Activity Relationship
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1006/abbi.1996.0291

Cytochrome P450 2D6 (CYP2D6) catalyzes the oxidation of substrates with a positively charged nitrogen atom 5–7 Å from the site of the oxidation. The active-site topology of CYP2D6 is examined here with phenyl-, 2-naphthyl-, andp-biphenyldiazene, which react with P450 enzymes to form σ-bonded aryl–iron (Fe–Ar) complexes. Ferricyanide-mediated migration of the aryl group from the iron to the porphyrin nitrogens produces theN-arylprotoporphyrin IX regioisomers (NB:NA:NC:ND, in which the aryl group is bound to the nitrogen of pyrrole rings B, A, C, and D, respectively) in the following ratios (zero means