FIGURE 6.

Kinetics of reduction of ferric cytochrome P450 by wild-type and mutant CYPOR in the presence of CO. The ΔA_N (normalized absorbance) represents the ratio between 450 nm A_∞ - A_t and 450 nm A_∞ - A_t = 0, where t = time and ∞ is infinity. The final cyt P450 and reductase concentration after mixing with NADPH was 5 μm. Final NADPH concentration was 50 μm. Experiments were conducted as described under “Experimental Procedures” with a saturated solution of CO in both syringes. BZ, benzphetamine.