Table 1

Kinetic parameters of CBZ 10,11-epoxidation, SMAP formation, and AND 6β-hydroxylation by human liver microsomes

Parameter	CBZ 10,11-Epoxidation^1-a		SMAP Formation from ZNS^1-b		AND 6β-Hydroxylation^1-a
Parameter	CBZ Only	Plus AND	Plus ZNS	ZNS Only	Plus CBZ	Plus AND	AND Only	Plus CBZ	Plus ZNS
K _m1	71.6	K _m = 268.7	63.0	K _m = 843.5	K _m = 1441.8	K _m = 24118.0	5.7	3.4	7.9
K _m2	1384.4	K _m = 268.7	1789.5	K _m = 843.5	K _m = 1441.8	K _m = 24118.0	537.6	382.4	455.6
V _max2	4.2	V _max = 2.7	5.2	V _max = 3.7	V _max = 3.5	V _max = 5.8	12.8	7.6	11.4
V _max/K _m				0.00443	0.00243	0.00024

Substrate concentrations used were 15 to 500 μM for CBZ, 15 to 1000 μM for ZNS, and 15 to 300 μM for AND. The reactions were performed in the absence or presence of 100 μM effectors. Units of the constants are as follows: K_m (apparent), micromolars; and V_max, nanomoles per milligram per minute.

↵1-a Analyzed by the modified two-site equation (V_max1 = 0) V = (V_max2S²/K_m1K_m2)/(1 + S/K_m1 +S²/K_m1K_m2) (Korezekwa et al., 1998)
↵1-b Analyzed by Michaelis-Menten equation V = V_max/(1 + (K_m/S))