The properties of enzyme activities hydrolysing the sulphate esters of dehydroepiandrosterone, oestrone and p-nitrophenol are reported. The preparation studied was obtained from the microsomal fraction of human placenta by ultrasonic treatment and addition of Triton X-100. 2. The behaviour of the preparation during sedimentation at 105000g and attempts at purification indicated that the activities were particulate. Electron microscopy demonstrated the rupture of vesicular structures approx. 0.5mu in diameter concurrent with the release of activity. 3. The three activities were always associated throughout repeated attempts at separation by sucrose-density-gradient centrifugation and Sephadex-gel filtration. On the basis of kinetic studies, stability studies and treatment with butanol and ribonuclease it was concluded that a separate enzyme is responsible for each of the three activities. Widely varying plots of activity as a function of pH were consistent with this conclusion. 4. On the basis of sensitivity of the enzymes hydrolysing dehydroepiandrosterone sulphate and oestrone sulphate to ribonuclease and sensitivity of all three enzymes to lipase, it was concluded that the three enzymes are bound to a particle containing lipid and RNA. Enzymic activity is dependent on structural integrity of the particle. 5. A spectrophotometric method for the assay of oestrone sulphate hydrolysis is described. 6. Hydrolysis of nitrocatechol sulphate by human placenta under conditions described for arylsulphatases A and B is reported.
摘要
本文报道了水解脱氢表雄酮、雌酮和对硝基苯酚硫酸酯的酶活性特性。所研究的制剂是通过超声处理和添加 Triton X - 100 从人胎盘微粒体部分获得的。2. 该制剂在 105000g 离心沉降过程中的行为以及纯化尝试表明，这些活性是颗粒状的。电子显微镜显示直径约 0.5μm 的囊泡结构破裂，同时活性释放。3. 在通过蔗糖密度梯度离心和 Sephadex 凝胶过滤进行的多次分离尝试中，这三种活性始终相关联。基于动力学研究、稳定性研究以及用丁醇和核糖核酸酶处理，得出结论：三种活性分别由一种单独的酶负责。活性随 pH 变化的广泛不同曲线与该结论一致。4. 基于水解脱氢表雄酮硫酸酯和雌酮硫酸酯的酶对核糖核酸酶的敏感性以及所有三种酶对脂肪酶的敏感性，得出结论：这三种酶与含有脂质和 RNA 的颗粒结合。酶活性取决于颗粒的结构完整性。5. 描述了一种用于测定雌酮硫酸酯水解的分光光度法。6. 报道了在针对芳基硫酸酯酶 A 和 B 所述的条件下人胎盘对硝基儿茶酚硫酸酯的水解情况。
