BIOLOGICAL CHEMISTRY OF SULFUR AND SELENIUM

建议对硫的生物化学进行研究。 硒和二硒醚中的硫醇和二硫化物的形态及硒 表格。这项研究将集中在化学反应上，这些化学反应是 硫和硒的生物化学，但尚未被 由于缺乏实验方法而定量描述的。 反应将在分子水平上完整地表征 用核磁共振波谱测定红细胞、血浆和水溶液。另外， 将开发灵敏和选择性的方法来测定 生物中的硫醇、二硫化物、硒醇、二硒醚和硒硫化物 液体和红细胞的高效液相色谱检测 具有电化学检测功能。 完整红细胞中硫和硒化合物的研究将是 旨在表征它们在红血球中的运输 膜及其细胞内代谢。这些研究将需要 利用非侵入性核磁共振方法的独特能力提供 不仅是关于膜运输的信息，也是关于 被运输的分子。高效液相色谱方法将用于测定 在微量水平上形成的代谢物。的动力学和平衡点。 硫醇与二硫化物和二硒化物的反应将是 用~1H和~(13)C-核磁共振对其在水溶液和血浆中的结构进行了表征。另外， 亚硒酸盐与生物分子中的硫醇基团的反应，这 被认为是将硒结合到生命系统中的一种方式， 将通过~1H、~(13)C和~(77)Se-核磁共振进行研究。重点将放在 表征反应的动力学和产物，以及 ~(77)Se-核磁共振仪的研制 通过这个反应，硒不仅可以变成小分子，还可以变成蛋白质。 这项拟议的研究将提供有关 将含硫和含硒的分子输送到红细胞， 它们在红细胞中的代谢，以及它们的内在还原强度 硫醇和硒醇基存在于各种生物分子中。另外， 将获得有关反应的信息，这些反应是 含硒酶谷胱甘肽过氧化物酶。高效液相色谱分析方法为 开发的方法将是对现有方法的重大补充 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.