TABLE 2

Apparent kinetic parameters for the formation of 2-hydroxymetronidazole by cDNA-expressed human P450 enzymes

	2-Hydroxymetronidazole Formation
Sample	K_m^{^a} or S₅₀^{^a}	V_max^{^a}	N^{^a,b}	Cl_int^{^c}
	mM	nmol/nmol P450  per minute		ml/nmol P450 per minute
CYP2A6	0.289 ± 0.061	0.65 ± 0.02	—	2.24
CYP3A4	5.38 ± 0.42	2.49 ± 0.11	1.65 ± 0.12	0.46
CYP3A5	4.45 ± 0.24	3.46 ± 0.10	1.88 ± 0.11	0.77
CYP3A7	8.96 ± 1.03	1.27 ± 0.06	—	0.14

↵^a Value ± S.E. of parameter fit; ^bcooperativity coefficient; ^cintrinsic clearance defined as V_max/K_m or V_ma_x/S₅₀.