. 2013 Jan;41(1):170–179. doi: 10.1124/dmd.112.049171

TABLE 1.

Enzyme kinetics summary of UGT2A2_i1 and UGT2A3 activities against PAHs. V_max, K_M, and V_max/K_M represent the mean of three independent experiments.

Substrate	UGT2A2_i1^a			UGT2A3^b
Substrate	K_M	V_max	V_max/K_M	K_M	V_max	V_max/K_M
	μM	pmol/min/mg	μl/min/mg	μM	pmol/min/mg	μl/min/mg
1-OH-pyrene	100 ± 15	38 ± 2.1	0.38 ± 0.03	363 ± 38	5.5 ± 0.2	0.01 ± 0.001^*
1-Naphthol	106 ± 15	26 ± 1.5	0.25 ± 0.04	148 ± 18	3.1 ± 0.2	0.02 ± 0.003^*
1-OH-B(a)P	279 ± 40	8.2 ± 0.8	0.03 ± 0.004		BLD
3-OH-B(a)P	332 ± 54	7.4 ± 0.5	0.02 ± 0.002		BLD
7-OH-B(a)P	240 ± 29	8.5 ± 0.4	0.04 ± 0.008		BLD
8-OH-B(a)P	287 ± 37	9.3 ± 0.6	0.03 ± 0.002		BLD
5-Methylchrysene-1,2-diol		BLD			BLD
B(a)P-7,8-diol		BLD			BLD
Dibenzo(a,l)pyrene-11,12-diol		BLD			BLD

BLD, below limit of detection.

^{^a}

Data expressed as milligrams of total protein homogenate, corrected for relative wild-type UGT2A2 expression as determined by real-time PCR.

^{^b}

Data expressed as milligrams of total protein homogenate, corrected for relative UGT2A3 expression as determined by real-time PCR.

P < 0.01 versus UGT2A2_i1 activity.