TABLE 1

Kinetic parameter estimates for the formation of carbamazepine-10,11-epoxide in HLM and rCYP3A4 according to the two-site equation (Korzekwa et al., 1998)

V_max1 was set to 0 when relative parameter errors supported the removal of V_max1 from the two-site equation. Estimates are given as ± S.D. of the fit.

Data Fitted	Equation	V_max ^a	n	S₅₀ ^b	K_m1 ^b	V_max1 ^a	K_m2 ^b	V_max2 ^a
HLM	Hill	0.67 ± 0.02	1.67 ± 0.07	415 ± 19
No felbamate	Two-site				617 ± 133	0.10 ± 0.07	214 ± 34	0.71 ± 0.02
	Two-site, V_max1 = 0				516 ± 109		204 ± 31	0.71 ± 0.02
HLM	Hill	0.77 ± 0.03	1.40 ± 0.05	471 ± 31
1 mM felbamate	Two-site				273 ± 175	0.12 ± 0.12	418 ± 97	0.83 ± 0.06
	Two-site, V_max1 = 0				97 ± 26		517 ± 74	0.89 ± 0.04
rCYP3A4	Hill	1.05 ± 0.02	1.47 ± 0.06	129 ± 5.3
No felbamate	Two-site				612 ± 96	2.47 ± 0.34	118 ± 31	0.89 ± 0.04
rCYP3A4	Hill	1.12 ± 0.01	1.53 ± 0.06	101 ± 3.4
500 μM felbamate	Two-site				345 ± 99	1.52 ± 0.52	60.0 ± 15.3	1.07 ± 0.03

↵ ^a Units are in nanomoles per minute per milligram HLM and nanomoles per minute per picomole rCYP
↵ ^b Units are in micromolar