Active Site Structure and Chemistry in Enzymatic Sulfite Reduction

酶促亚硫酸盐还原中的活性位点结构和化学

• 批准号: 8921468
• 负责人: James Cowan
• 金额: $ 34.63万
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-15 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8921468&HistoricalAwards=false
• 关键词: Active; Site; Structure; Chemistry; Enzymatic

With support from the Inorganic, Bioinorganic and Organometallic Chemistry Program and the Biochemistry Program Dr. James A. Cowan and Dr. Richard P. Swenson will investigate the active site structure and mechanism of a metalloprotein from the bacterium Desulfovibrio vulgaris which mediates the reduction of sulfite. This enzyme is involved in the overall reduction of sulfate to hydrogen sulfide, an extremely important natural process, particularly in the ecology of wetlands. The development of a clear understanding of structure/function relationships for this relatively small multielectron redox enzyme is expected to also provide better insight into the operation of more complex and experimentally less tenable systems, such as the human respiratory enzymes. A variety of physical methods, including NMR spectroscopy, will be used to characterize the structural environment of the enzyme active site, in terms of the ligands coordinating to the prosthetic groups and of neighboring residues that might be involved in catalysis. Sulfite labeled with S-35 and O-18 will be used to investigate the mechanism of the enzyme. Exchange interactions and the coordination and redox chemistry of the coupled siroheme-Fe4S4 complex in both the native enzyme and with bound exogenous ligands will be studied. A cloning program will be developed for the dual purpose of providing larger quantities of the enzyme and, by mutagenesis, to clarify the roles of specific residues in the function of the enzyme.

在无机、生物无机和 有机化学专业和生物化学专业 James A.科万和理查德·P·斯文森博士将进行调查 金属蛋白活性中心结构与作用机制 来自细菌普通脱硫弧菌，其介导 还原亚硫酸盐。这种酶参与了 硫酸盐还原为硫化氢，这是一种非常 重要的自然过程，特别是在生态学中 湿地发展一个清晰的认识， 结构/功能关系相对较小 多电子氧化还原酶预计也提供更好的 深入了解更复杂和实验性的操作 不太稳定的系统，例如人类呼吸酶。 各种物理方法，包括核磁共振光谱，将 用于描述结构环境的特征 酶活性位点，就与酶配位的配体而言 辅基和相邻残基的结合 参与催化作用。用S-35和O-18标记的亚硫酸盐将 用于研究酶的作用机制。交换 的相互作用和协调和氧化还原化学的 偶联siroheme-Fe 4S 4复合物在天然酶和 将研究与结合的外源配体。克隆程序 将开发用于提供更大的 量的酶，并通过诱变，以澄清 特定残基在酶功能中的作用。