Mechanisms and Functions of Human Sulfotransferases

II相药物代谢酶磺基转移酶（SULT）催化的硫酸化在药物代谢中是重要的。 调节不同的激素和解毒药物和其他外源性物质。硫酸化也导致 导致毒性作用的前致癌物的生物活化。该研究项目的长期目标是 了解人类SULT的生物学功能，并研究它们与人类健康的相关性， 生理和病理条件。本提案的具体目标如下：1.探讨 人SULT的催化、底物抑制和产物抑制/激活机制。的 提出的旁路有序机制和相关的替代机制将使用动力学研究 分析、同位素交换、硫酸化活性位点氨基酸残基鉴定和定点 诱变这些信息将对生物转化的预测具有重要意义 途径。2.研究硫酸化药物对人SULT催化活性的影响。的抑制 临床上重要的药物硫酸盐对人SULT催化活性的活化作用将是 研究了E.大肠杆菌表达和纯化的人SULT;人肠胞质溶胶;和人Hep G2 Caco-2细胞将用于这些研究。临床药物对人SULT活性的影响 可能干扰SULT在激素调节和异生物质解毒方面的正常生物学功能。3.到 定义人SULT 1 E1的氧化调节机制。人SULT 1 E1在人乳腺癌中的氧化调节作用 Hep G2和Caco-2细胞以及纯化的人SULT 1 E1的氧化还原巯基调节机制将在本研究中进行。 采用酶法、Western blot、RT-PCR、氨基酸修饰、定点 诱变、动力学分析、晶体结构分析和计算机建模方法。知识 某些人SULT的氧化调节对于理解SULT功能的能力是重要的 在生理和病理条件下。 该提案研究人类SULT。这些研究对于理解SULT具有重要意义 生物功能包括激素调节、药物代谢、异生物质解毒和 前致癌物生物活化这些知识对于认识药物的副作用、药物间的相互作用等都有重要意义 相互作用、药物开发以及SULT在癌症预防和病因中发挥的潜在作用。

Phase II drug metabolizing enzymes sulfotransferases (SULTs) catalyzed sulfation is important in the regulation of different hormones and the detoxification of drugs and other xenobiotics. Sulfation also leads to bioactivation of procarcinogens leading to toxic effect. The long-term goal of this research project is to understand human SULT biological functions and to investigate their relevance to human health under physiological and pathological conditions. Specific aims in this proposal are as follows: 1. To Investigate Mechanisms of Catalysis, Substrate Inhibition, and Product Inhibition/Activation of Human SULTs. The proposed bypass ordered mechanism and related alternative mechanisms will be investigated using kinetic analysis, isotope exchange, sulfated active site amino acid residue identification, and site-directed mutagenesis. The information will have important implications for the prediction of biotransformation pathways. 2. To Investigate the Effect of Sulfated Drugs on Human SULT Catalytic Activities. The inhibition and activation effect of clinically important drug sulfates on catalytic activities of human SULTs will be investigated. E. coli expressed and purified human SULTs; human intestinal cytosols; and human Hep G2 and Caco-2 cells will be used for these investigations. The effect of clinical drugs on human SULT activities may interfere SULT normal biological functions in hormone regulation and xenobiotic detoxification. 3. To Define Oxidative Regulation Mechanisms of Human SULT1E1. Oxidative regulation of human SULT1E1 in Hep G2 and Caco-2 cells and redox thiol regulation mechanisms of purified human SULT1E1 will be investigated using enzyme assay, Western blot, RT-PCR, amino acid modification, site-directed mutagenesis, kinetic analysis, crystal structure analysis, and computer modeling methods. Knowledge on oxidative regulation of certain human SULT is important in understanding the ability of SULT functioning under physiological and pathological conditions. This proposal studies human SULTs. These studies will be significant in understanding SULT biological functions including hormone regulation, drug metabolism, xenobiotic detoxification and procarcinogen bioactivation. The knowledge will be important in understanding drug side effect, drug-drug interaction, drug development, and the potential roles SULTs play in cancer prevention and causation.