TABLE 1.

Apparent K_M and k_cat values of CYP2B4 for CPR in the presence of increasing concentrations of CYP2E1 WT

The apparent K_M and k_cat values of CYP2B4 for CPR were determined as described under Materials and Methods. Since CYP2E1 does not metabolize BNZ, the kinetic parameters for CPR binding to CYP2B4 could be determined by measuring the rate of formaldehyde formation using fixed concentrations of CYP2B4 and BNZ with increasing concentrations of CPR and CYP2E1. The kinetic values given here were derived from data in Fig. 3.

[2E1]	KM	kcat
μM	μM	min–1
0	0.08 ± 0.01	118 ± 2.2
0.125	0.18 ± 0.014	85 ± 1.8
0.25	0.77 ± 0.13	103 ± 8.7
0.75	1.86 ± 0.61	106 ± 23
1.25	0.18 ± 0.04	33 ± 2.2
1.50	0.20 ± 0.06	11 ± 1.0