4-ethenylidene steroids as mechanism-based inactivators of 3β-hydroxysteroid dehydrogenases
作者:Venkataraman Balasubramanian、Ian R. McDermott、Cecil H. Robinson
DOI:10.1016/0039-128x(82)90117-9
日期:1982.7
The synthesis of 4-ethenylidene-5 alpha-androstane-3 beta, 17 beta-diol (5) and of 4-ethenylidene-5 alpha-androstane-3, 17-dione (4) is described. Compound 5 is a competitive inhibitor of solubilized bovine microsomal adrenal delta-5-3 beta-hydroxysteroid dehydrogenase, with Ki = 2.7 microM, and is converted by the enzyme to the corresponding 3-ketone. Compound 4 is shown to irreversibly inactivate
描述了 4-ethenylidene-5 α-androstane-3 beta, 17 beta-diol (5) 和 4-ethenylidene-5 alpha-androstane-3, 17-dione (4) 的合成。化合物 5 是溶解的牛微粒体肾上腺 delta-5-3 β-羟基类固醇脱氢酶的竞争性抑制剂,Ki = 2.7 microM,并被酶转化为相应的 3-酮。化合物 4 显示出以时间依赖性方式不可逆地灭活酶(t 1/2 = 31 分钟;55 microM;pH = 7.0)。底物脱氢表雄酮可防止化合物 4 失活。相反,化合物 5 不会在 3-位被睾丸睾酮的 3β-(和 17β)-羟基类固醇脱氢酶氧化,而是在 17-位被氧化。位置。然而,4-亚乙烯基-3,17-二酮 (4) 会导致不可逆的时间依赖性失活(t 1/2 = 28 分钟;64 微米;pH = 7.0) 当与这种细菌酶直接孵育时,充当亲和标记。