TABLE 1

Kinetic parameters of FOSA N-glucuronide formation in liver microsomes from humans, rats, dogs, and monkeys and in recombinant hUGT2B4 and hUGT2B7

The kinetic parameters were derived from nonlinear regression analysis of the experimental data by fitting to a single-enzyme model or Hill equation. Each value represents best-fit values ± S.D. of triplicate points. Kinetic plots are presented in Fig. 2.

	S ₅₀ ^a	V _max	CL_max^b	n ^a
	μM	pmol/min/mg protein	μl/min/mg protein
Human	143 ± 6	732 ± 18	2.75	3.19 ± 0.42
Dog	195 ± 17	193 ± 12	0.50	2.46 ± 0.31
Monkey	189 ± 13	255 ± 14	0.70	2.73 ± 0.32
	K _m ^a	V _max	CL_int^c
	μM	pmol/min/mg protein	μl/min/mg protein
Rat	122 ± 9	355 ± 9	2.91
hUGT2B4	847 ± 122	88.8 ± 7.6	0.108
hUGT2B7	361 ± 32	1546 ± 71	4.33

↵ a S₅₀ and n (Hill coefficient) calculated by Hill equation; K_m calculated by Michaelis-Menten equation.
↵ b CL_max calculated as described under Material and Methods.
↵ c CL_int calculated as V_max/K_m.