Adams J B, Phillips N S
School of Biochemistry, University of New South Wales, Sydney, Australia.
J Steroid Biochem. 1990 Aug 28;36(6):695-701. doi: 10.1016/0022-4731(90)90190-4.
Partial purification (approximately x 140-fold) of estrogen sulphotransferase (EC 2.8.2.4) in human mammary estrogen receptor positive cancer tissue was achieved by affinity chromatography on adenosine-3',5'-diphosphate-agarose. It had a Mr of approximately 70,000 by gel filtration and upon electrophoresis on concave gradient polyacrylamide gels, showed a major (Mr 70,000) and a minor (Mr 200,000) peak of activity. Kinetics of this preparation (estradiol-17 beta and estrone as substrates), and also that of hydroxysteroid sulphotransferase (EC 2.8.2.2) contained in the cytosol of human mammary cancer MCF-7 cells (5-androstene-3 beta,17 beta-diol and dehydroepiandrosterone as substrates), were compared. The enzymes showed very similar behaviour, characterized by high affinity for their steroid substrates (low nM range) and co-operativity in their binding. For hydroxysteroid sulphotransferase, the adrenal-derived estrogen 5-androstene-3 beta,17 beta-diol was the preferred substrate compared to dehydro-epiandrosterone in the 0-40 nM concentration range. Such properties of the enzymes might be designed to limit the exposure of nuclear receptor to free ligand. Alternatively, a defined subcellular location would perhaps involve the enzymes in the elimination of estrogen after processing of the ligand-bound receptor.
通过在3',5'-二磷酸腺苷琼脂糖上进行亲和层析，对人乳腺雌激素受体阳性癌组织中的雌激素磺基转移酶（EC 2.8.2.4）进行了部分纯化（约140倍）。通过凝胶过滤法测得其分子量约为70,000，在凹形梯度聚丙烯酰胺凝胶上进行电泳时，显示出一个主要的（分子量70,000）和一个次要的（分子量200,000）活性峰。比较了该制剂（以雌二醇-17β和雌酮为底物）以及人乳腺癌MCF-7细胞胞质溶胶中所含的羟类固醇磺基转移酶（EC 2.8.2.2）（以5-雄烯-3β,17β-二醇和脱氢表雄酮为底物）的动力学。这些酶表现出非常相似的行为，其特征是对类固醇底物具有高亲和力（低纳摩尔范围）且在结合过程中具有协同性。对于羟类固醇磺基转移酶，在0至40纳摩尔浓度范围内，与脱氢表雄酮相比，肾上腺来源的雌激素5-雄烯-3β,17β-二醇是更优选的底物。这些酶的此类特性可能旨在限制核受体与游离配体的接触。或者，特定的亚细胞定位可能使这些酶在处理配体结合的受体后参与雌激素的消除。
