Dansette P M
Ann Biol Clin (Paris). 1980;38(1):25-34.
Microsomal epoxide hydrolase (EC 3.3.2.3. ; formerly EC 4.2.1.63) catalyse the hydration of epoxides into trans dihydro-diols, easily excretable hydrophil compounds. It is an enzyme with very wide specificity for monosubstituted oxiranes, or cis disubstituted oxiranes. It is inactive on polysubstituted epoxides. The hydration is stereospecific with the attack of a carbon S and inversion of the configuration to give a dihydro-diol (R,R). Epoxide hydrolase was purified from microsomes of rat and human liver. It is a hydrophobic protein of molecular weight 49 000, the presence of which may be shown immunochemically or enzymatically in numerous organs. Its insertion in the microsomal membranes renders difficult precise kinetic studies. The enzyme concentration is high, which compensates an average catalytic power. The role of epoxide hydrolase is ambiguous : in general, it protects against reactive electrophilic spoxides, but it is also an agent of toxic activation in the case of polycyclic hydrocarbons with a bay region.
微粒体环氧化物水解酶（EC 3.3.2.3；原EC 4.2.1.63）催化环氧化物水合形成反式二氢二醇，即易于排泄的亲水性化合物。它是一种对单取代环氧乙烷或顺式二取代环氧乙烷具有非常广泛特异性的酶。它对多取代环氧化物无活性。水合反应具有立体特异性，即碳S发生进攻，构型翻转生成二氢二醇（R,R）。环氧化物水解酶是从大鼠和人肝脏的微粒体中纯化得到的。它是一种分子量为49000的疏水蛋白，其存在可通过免疫化学或酶学方法在许多器官中显示出来。它插入微粒体膜使得精确的动力学研究变得困难。该酶浓度较高，这弥补了其一般的催化能力。环氧化物水解酶的作用尚不明确：一般来说，它可保护机体免受亲电活性环氧化物的侵害，但在具有湾区的多环烃的情况下，它也是一种毒性激活剂。
