TABLE 1

Steady-state parameters for pNP glucuronidation by substituted UGT1A10 enzymes Parameters were determined from the fit of initial velocities to a Michaelis-Menten kinetic scheme using the software GraphPad Prism.

UGT Isoform	pNP					UDP-GlcUA
UGT Isoform		V_max	K_m	V_max/K_m	V_max	K_m	V_max/K_m
	μM min^–1 mg^–1 protein	μM	min^–1 mg^–1 protein	μM min^–1 mg^–1 protein	μM	min^–1 mg^–1 protein
1A10 WT	13.8 ± 0.6	323 ± 54	0.043 ± 0.007	7.0 ± 0.3	323 ± 54	0.022 ± 0.004
D393A
Q394A
D396A	4.7 ± 0.2	286 ± 56	0.016 ± 0.003	7.2 ± 0.6	490 ± 150	0.015 ± 0.004
K399A	67 ± 5	940 ± 170	0.071 ± 0.013	22 ± 2	480 ± 140	0.046 ± 0.013

WT, wild type