Table 3.

Apparent inhibition parameters for styrene metabolites toward recombinant CYP2E1 activity.^a,^b

Inhibitor	LogP	Mechanism	kcat2 c	Ki,ap (μM)	Ksi,ap (μM)
Styrene	2.71	Mixed cooperative substrate	19 (17–21)	67 (56–80)	1100 (700–2000)
Styrene oxide	1.74	Mixed cooperative substrate	19 (17–21)	110 (76–170)	1000 (450–10 000)
4-Vinylphenol	2.41	Mixed cooperative substrate	–	47 (33–72)	230 (120–1500)
R/S-Styrene glycol	0.58	Competitive	–	29 000 (19 000–52 000)	–

^aFigure 2 depicts reaction mechanism used to determine kinetic parameters. Nonsymmetrical 95% confidence intervals for parameters are shown in parentheses.

^bParameters for uninhibited 4-nitrophenol oxidation by recombinant CYP2E1 were K_s 290 μM, K_ss 1700 μM and k_cat1 19 nmol/min/nmol CYP2E1.

^cUnits are nmol/min/nmol CYP2E1.