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Increased Phenacetin Oxidation Upon The L382v Substitution In Cytochrome P450 1a2 Is Associated With Altered Substrate Binding Orientation, Qingbiao Huang, Grazyna D. Szklarz

Faculty & Staff Scholarship

Leucine382 of cytochrome P450 1A2 (CYP1A2) plays an important role in binding and O-dealkylation of phenacetin, with the L382V mutation increasing substrate oxidation (Huang and Szklarz, 2010, Drug Metab. Dispos. 38:1039–1045). This was attributed to altered substrate binding orientation, but no direct experimental evidence had been available. Therefore, in the current studies, we employed nuclear magnetic resonance (NMR) longitudinal (T1) relaxation measurements to investigate phenacetin binding orientations within the active site of CYP1A2 wild type (WT) and mutants. Paramagnetic relaxation time (T1P) for each proton of phenacetin was calculated from the T1 value obtained from the enzymes in ferric and …