Akao T, Akao T, Kobashi K
Faculty of Pharmaceutical Sciences, Toyama Medical and Pharmaceutical University, Japan.
Biochim Biophys Acta. 1990 Oct 1;1046(3):271-6. doi: 10.1016/0005-2760(90)90241-o.
A NADP(+)-dependent 3 beta-hydroxysteroid dehydrogenase activity was localized in the microsomal fraction of rat liver. This enzyme was solubilized and separated completely from 3 alpha-hydroxysteroid dehydrogenase by Matrex red A column chromatography. Partially purified 3 beta-hydroxysteroid dehydrogenase catalyzed the oxidation and reduction between the 3 beta-hydroxyl and 3-ketonic group of steroids or bile acids having no double bond in the A/B ring, but was inactive toward 3 alpha-hydroxyl group. The enzyme required NADP+ for oxidation and NADPH for reduction. The activity was inhibited by p-chloromercuribenzoic acid or p-chloromercuribenzenesulfonic acid at the concentration of 10(-4) M. The molecular weight of the enzyme was estimated to be about 43,000 by Sephadex G-200 column chromatography. From these results, it is concluded that the enzyme is a new type of microsomal NADP+:3 beta-hydroxysteroid dehydrogenase.
一种依赖烟酰胺腺嘌呤二核苷酸磷酸（NADP⁺）的3β-羟基类固醇脱氢酶活性定位于大鼠肝脏的微粒体部分。该酶通过Matrex红A柱色谱法溶解，并与3α-羟基类固醇脱氢酶完全分离。部分纯化的3β-羟基类固醇脱氢酶催化A/B环中无双键的类固醇或胆汁酸的3β-羟基与3-酮基之间的氧化和还原反应，但对3α-羟基无活性。该酶氧化反应需要NADP⁺，还原反应需要NADPH。该活性在10⁻⁴ M浓度的对氯汞苯甲酸或对氯汞苯磺酸作用下受到抑制。通过葡聚糖凝胶G-200柱色谱法估计该酶的分子量约为43,000。从这些结果可以得出结论，该酶是一种新型的微粒体NADP⁺：3β-羟基类固醇脱氢酶。
