Figure 13.

Kinetics of binding of ketoconazole to P450_BM-3. P450_BM-3 (4 μM, in 50 mM potassium MOPS buffer, pH 7.4) was mixed with 300 μM ketoconazole (in 50 mM potassium MOPS buffer, pH 7.4). A. Plot of ΔA₄₄₅-A₄₁₀ data measured either with no other ligands present (black line) or with 70 μM 11-OH lauric acid present (red line). The respective rates (single exponential fits) were 2.59 and 2.43 s⁻¹. B. Fit of data from mixing a P450_BM-3/11-OH lauric acid mixture with 300 μM ketoconazole and fitting to the equations