Hepatic microsomal cholesterol epoxide hydrolase: selective inhibition by detergents and separation from xenobiotic epoxide hydrolase.

Cholesterol epoxide hydrolase (CEHase) activities of mouse liver microsomes were completely inhibited by Emulgen 108 and Lubrol PX and approximately half by cholate, Triton WR-1339, and Tween 80 when preincubated with 0.1% of these detergents, while their xenobiotic epoxide hydrolase (XEHase) activities were markedly enhanced under the same preincubation conditions. The CEHase and XEHase activities were separately eluted from a gel column applied with mouse liver microsomes which were solubilized in a phosphate buffer containing cholate, glycerol, urea, dithiothreitol, and EDTA.