BIOLOGICAL CHEMISTRY OF SULFUR AND SELENIUM

建议研究硫的生物化学， 硫醇和二硫化物形式以及硒醇和二硒化物中的硒 forms. 这项研究将集中在化学反应，这是核心， 硫和硒的生物化学，但还没有被 由于缺乏实验方法而定量表征。 反应将在分子水平上进行表征， 红细胞、血浆和水溶液。 还有， 将开发灵敏和选择性的方法来测定 硫醇、二硫化物、硒醇、二硒醚和硒代硫化物 液体和红细胞（高效液相色谱法） 电化学检测。 完整红细胞中硫和硒化合物的研究将是 旨在表征它们在红细胞中的转运 膜和细胞内代谢。 这些研究将 非侵入性1H-NMR方法的独特能力的优势， 不仅是关于膜转运的信息， 运输的分子。 HPLC方法将用于测定 在痕量水平形成代谢物。 的动力学和平衡， 硫醇与二硫化物和二硒化物的反应将是 通过1H和13C-NMR在水溶液和血浆中表征。 还有， 亚硒酸盐与生物分子中巯基的反应， 被认为是将硒结合到生命系统中的一种方式， 用~1H、~（13）C和~（77）Se-NMR研究。 重点将是 表征反应的动力学和产物，和 开发77Se-NMR作为探测掺入的技术， 硒不仅转化为小分子，而且通过这种反应转化为蛋白质。 拟议的研究将产生新的基本信息， 含硫和硒分子转运到红细胞中， 它们在红细胞中的代谢，以及 巯基和硒醇基团。 还有， 将获得关于反应的信息，所述反应是以下反应的模型： 含硒酶谷胱甘肽过氧化物酶。 HPLC方法 开发将是一个重要的补充，以提供方法， 研究硫和硒的代谢

It is proposed to investigate the biological chemistry of sulfur in the thiol and disulfide forms and selenium in the selenol and diselenide forms. The research will focus on chemical reactions which are central to the biological chemistry of sulfur and selenium, but which have not been quantitatively characterized because of a lack of experimental methods. Reactions will be characterized at the molecular level in intact erythrocytes, plasma and aqueous solution by NMR spectroscopy. Also, sensitive and selective methods will be developed for the determination of thiols, disulfides, selenols, diselenides and selenosulfides in biological fluids and erythrocytes by high performance liquid chromatography (HPLC) with electrochemical detection. The studies of sulfur and selenium compounds in intact erythrocytes will be designed to characterize both their transport across the erythrocyte membrane and their intracellular metabolism. These studies will take advantage of the unique capability of noninvasive 1H-NMR methods to provide information not only about membrane transport but also about the fate of the transported molecule. The HPLC methods will be used to determine metabolites formed at trace levels. The kinetics and equilibria of the reaction of thiols with disulfides and with diselenides will be characterized in aqueous solution and in plasma by 1H and 13C-NMR. Also, the reaction of selenite with thiol groups in biological molecules, which is thought to be a means of incorporation of selenium into living systems, will be studied by 1H, 13C and 77Se-NMR. The emphasis will be on characterizing the kinetics and the products of the reaction, and developing 77Se-NMR as a technique for probing the incorporation of selenium not only into small molecules but also proteins by this reaction. The proposed research will yield new and fundamental information about the transport of sulfur and selenium-containing molecules into erythrocytes, their metabolism in erythrocytes, and the intrinsic reducing strength of thiol and selenol groups in a variety of biological molecules. Also, information will be obtained about reactions which are models for the selenium-containing enzyme glutathione peroxidase. The HPLC methods to be developed will be a significant addition to the methods available for studying sulfur and selenium metabolism.