Molecular Biology and Biochemistry of Nickel-Containing Hydrogenases

含镍氢化酶的分子生物学和生物化学

• 批准号: 9005734
• 负责人: Harry Peck
• 金额: $ 26.7万
• 依托单位: University of Georgia Research Foundation Inc
• 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: 1990-08-01 至 1994-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9005734&HistoricalAwards=false
• 关键词: Molecular; Biology; Biochemistry; Nickel; Containing

The long term objectives of this research are to understand hydrogen metabolism during the anaerobic growth of bacteria in terms of the enzymatic mechanisms of H2 activation, the catalytic roles of nickel and non-heme iron, the number and structure of hydrogenases, the mechanisms of their cellular localizations, the insertion of metal redox centers and the roles of hydrogenases in the bioenergetics of anaerobic bacteria. Hydrogenase and H2 are of general biological and biotechnological importance as they are intimately involved in dinitrogen fixation, the photoproduction of H2 from water, complex microbial fermentations useful for the production of fuels and chemicals, and as normal flora of the intestinal tracts of higher animals. The specific aims of the proposed research are: to obtain an x-ray crystallographic structure of the nickel- containing hydrogenases; to define the structure of the nickel- containing active site and the three iron non-heme iron clusters; to further refine the activation and catalytic cycles involved in H2 utilization; to develope a DNA transfer system for the sulfate reducing bacteria; to use this system for the biosynthesis of active hydrogenases with recombinant DNA; to prepare modified hydrogenases by site-directed mutagenesis and study from the sulfate reducing bacteria their biochemical properties; and to establish the roles of multiple hydrogenases in selected anaerobic microorganisms.

本研究的长期目标是从氢气活化的酶机制、镍和非血红素铁的催化作用、氢酶的数量和结构、氢酶的细胞定位机制、金属氧化还原中心的插入以及氢酶在厌氧细菌生物能量学中的作用等方面了解细菌在厌氧生长过程中的氢代谢。氢酶和氢气具有广泛的生物学和生物技术重要性，因为它们与固定氮、从水中光产生氢气、用于生产燃料和化学品的复杂微生物发酵以及高等动物肠道的正常菌群密切相关。拟议研究的具体目的是：获得含镍氢酶的X射线晶体结构；确定含镍活性中心和三个铁非血红素铁簇的结构；进一步完善氢利用中涉及的活化和催化循环；开发硫酸盐还原细菌的DNA转移系统；利用该体系与重组DNA生物合成活性氢酶；通过定点突变制备修饰的氢酶并研究硫酸盐还原细菌的生化性质；以及确定多种氢酶在选定的厌氧微生物中的作用。