TABLE 1

P450-selective probe reactions and their parameters that derive the RAF values for various P450 isoforms

P450 Isoform	Probe Reaction	HLMs			rP450			RAF
P450 Isoform	Probe Reaction	K_m,u	V_max	f_u	K_m,u	V_max	f_u
		µM	µM/min		µM	µM/min
CYP1A2	Phenacetin O-deethylation	66.3	0.514	1.00	5.7	0.733	1.00	0.061
CYP2C9	Diclofenac 4′-hydroxylation	22.4	0.040	0.80	7.9	0.034	0.84	0.415
	Tolbutamide 4-hydroxylation	236.5	0.058	0.95	76.7	0.114	0.92	0.164
	S-Warfarin 7-hydroxylation	10.2	0.002	0.83	6.9	0.004	0.95	0.289
CYP2C19	S-Mephenytoin 4′-hydroxylation	56.8	0.039	0.91	19.8	0.887	0.95	0.015
CYP2D6	Bufuralol 1′-hydroxylation	5.4	0.060	0.57	6.7	1.135	0.78	0.066
CYP3A4	Midazolam 1′-hydroxylation	4.8	3.878	0.60	3.3	2.981	0.70	0.904
	Nifedipine dehydrogenation	8.4	0.754	0.58	6.3	0.770	0.77	0.734
	Testosterone 6β-hydroxylation	10.2	0.668	0.78	8.0	17.960	0.82	0.029