Structural Study of Sulfotransferases

工作概述：巯基转移酶代谢是一种类固醇激素等生物信号的失活过程，也是一种抵御环境毒物和致癌物质的防御系统。面对几乎无限数量的结构多样的化学物质，这些酶表现出广泛的底物特异性。因此，研究决定底物特异性的结构原理，以预测代谢及其对人类化学暴露敏感性的影响是很重要的。为了进行研究，我们使用了x射线晶体学和定点诱变。我们解决了雌激素硫转移酶（EST）与PAP与雌二醇配合以及PAP与钒酸盐配合的晶体结构。这些结构为了解硫转移酶催化的反应机理提供了新的思路。基于结构的定点诱变定义了EST底物口袋中的狭窄样门，该门赋予该酶雌激素特异性。-硫转酶，x射线晶体学，酶作用，定点诱变，蛋白质表达和纯化

Summary of Work: Metabolism by sulfotransferases is an inactivation of biological signals such as steroid hormones and also a defense system against environmental toxicants and carcinogens. To encounter virtually unlimited numbers of structurally diverse chemiclas, these enzymes exhibit broad substrate specificity. Thus, it is important to investigate the structural principle determining the substrate specificity in order to predict the metabolisms and the resulted consequences to human susceptibililty to chemical exposure. For the investigation, we have used x-ray crystallography and site-directed mutagenesis. We have solved the crystal structure of estrogen sulfotransferase (EST) complexed with PAP and estradiol and that with PAP and vanadate. These structures provided the insight into understanding the reaction mechanism catalyzed by sulfotransferase. Site-directed mutagenesis based on the structres defined the stricture- like gate in the substrate pocket of EST that confers estrogen specificity to the enzyme. - Sulfotranserase, x-ray crystallography, enzyme action, site-directed mutagenesis, protein expression and purification