Comer K A, Falany C N
Department of Pharmacology, University of Rochester, New York 14642.
Mol Pharmacol. 1992 Apr;41(4):645-51.
Dehydroepiandrosterone sulfotransferase (DHEA-ST), a steroid sulfotransferase (ST), has recently been purified from human liver cytosol and partially characterized. DHEA-ST has a subunit molecular mass of 35 kDa and is responsible for the majority of the sulfation of steroids and bile acids in the liver. For these studies, polyclonal antibodies to human liver DHEA-ST were raised in rabbits. The anti-human liver DHEA-ST antibodies were used to characterize the immunoreactivity of DHEA-ST in human liver and to study the relationship of human adrenal DHEA-ST to the liver form of the enzyme. Immunoblot analysis of several different human liver cytosol samples with the rabbit anti-human liver DHEA-ST antiserum detected only a single 35-kDa protein in each liver. Anti-human liver DHEA-ST antibodies also did not react with either form of phenol sulfotransferase (PST), P-PST or M-PST, present in human liver cytosol. DHEA-ST activity was purified from the 100,000 x g supernatant fraction of human adrenal tissue by DEAE-Sepharose CL-6B chromatography and 3',5'-diphosphoadenosine-agarose affinity chromatography. Human adrenal DHEA-ST was shown to have a molecular mass of 35 kDa, by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immunoblot analysis of human adrenal cytosol revealed that the anti-human liver DHEA-ST antibodies reacted specifically with the 35-kDa subunit of DHEA-ST. The apparent Km values for DHEA and 3'-phosphodenosine-5'-phosphosulfate obtained with human adrenal DHEA-ST were 1.0 microM and 1.6 microM, respectively. Adrenal DHEA-ST demonstrated the same pattern of reactivity towards different steroid substrates as did human liver DHEA-ST, and neither form of DHEA-ST was found to sulfate cortisol. The results of this study suggest that DHEA-ST is the major steroid ST present in human liver and adrenal tissue and that the physical, biochemical, and kinetic properties of adrenal DHEA-ST are similar if not identical to those of the liver form of the enzyme.
硫酸脱氢表雄酮硫酸转移酶（DHEA - ST）是一种类固醇硫酸转移酶（ST），最近已从人肝脏胞质溶胶中纯化出来并进行了部分特性鉴定。DHEA - ST的亚基分子量为35 kDa，负责肝脏中大部分类固醇和胆汁酸的硫酸化作用。在这些研究中，用兔制备了针对人肝脏DHEA - ST的多克隆抗体。抗人肝脏DHEA - ST抗体用于鉴定人肝脏中DHEA - ST的免疫反应性，并研究人肾上腺DHEA - ST与肝脏形式的该酶之间的关系。用兔抗人肝脏DHEA - ST抗血清对几种不同的人肝脏胞质溶胶样品进行免疫印迹分析，结果显示每个肝脏中仅检测到一种35 kDa的蛋白质。抗人肝脏DHEA - ST抗体也不与人肝脏胞质溶胶中存在的两种形式的酚硫酸转移酶（PST），即P - PST或M - PST发生反应。通过DEAE - Sepharose CL - 6B层析和3'，5'-二磷酸腺苷 - 琼脂糖亲和层析从人肾上腺组织的100,000×g上清液组分中纯化DHEA - ST活性。通过十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳显示人肾上腺DHEA - ST的分子量为35 kDa。对人肾上腺胞质溶胶的免疫印迹分析表明，抗人肝脏DHEA - ST抗体与DHEA - ST的35 kDa亚基发生特异性反应。用人肾上腺DHEA - ST测得的DHEA和3'-磷酸腺苷 - 5'-磷酸硫酸酯的表观Km值分别为1.0 microM和1.6 microM。肾上腺DHEA - ST对不同类固醇底物的反应模式与人类肝脏DHEA - ST相同，并且未发现任何一种形式的DHEA - ST对皮质醇进行硫酸化。这项研究的结果表明，DHEA - ST是存在于人肝脏和肾上腺组织中的主要类固醇ST，并且肾上腺DHEA - ST的物理、生化和动力学特性即使与肝脏形式的该酶不完全相同也很相似。
