Role of the P Clusters and FeMo-Cofactors in Nitrogenase Catalysis

P 簇和 FeMo 辅因子在固氮酶催化中的作用

• 批准号: 1330807
• 负责人: John Peters
• 金额: $ 45.04万
• 依托单位: Montana State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1330807&HistoricalAwards=false
• 关键词: Role; Clusters; FeMo; Cofactors; Nitrogenase

The proposed work involves implementing a multidisciplinary approach using basic biochemistry, spectroscopy, and x-ray crystallography techniques to probe some of the key outstanding issues regarding the mechanism of the key enzyme in nitrogen fixation, nitrogenase. We will probe the hypothesis that the redox-dependent structural changes are key to modulating the midpoint potential and defining the role of the P cluster in gated intermolecular electron transfer. The combined use of key site-directed variants and a europium complex redox mediator will facilitate the capture of defined states of the enzyme relevant to the catalytic mechanism that are not possible to observe in the native state, and will answer questions regarding substrate binding to the FeMo-cofactor. Basic research on biological nitrogen fixation could contribute to less energy demanding and more environmentally sound mechanisms to meet the growing demands for fixed nitrogen associated with global population growth, as the availability of fixed nitrogen sources for plant growth is a limiting factor in global nutrition and the production of nitrogenous fertilizers is very energy demanding and can have negative environmental implications. Broader Impacts include student training and significant contributions to training K-12 teachers through the development of an online course on Agriculture and Energy along with other efforts aimed at teachers in remote rural areas that include tribal schools.

提出的工作涉及使用基本的生物化学，光谱和X射线晶体学技术实施多学科方法，以探测有关氮固定中关键酶机制的一些关键问题，即氮气中的氮基酶。我们将探究以下假设：依赖氧化还原的结构变化是调节中点电位并定义P簇在门控分子间电子转移中的作用的关键。关键位置定向变体和Europium Complex氧化还原介体的联合使用将有助于捕获与催化机制相关的酶的定义状态，这些酶在本地状态无法观察，并将回答有关与Femo-Cofactor的底物结合的问题。生物氮固定的基础研究可能导致能量减少，并且在环境方面的声音机制更少，以满足对与全球人口增长相关的固定氮需求不断增长的需求，因为植物生长的固定氮来源的可用性是全球营养中的限制因素，是氮肥的产生，氮气的生产非常需要能源需求和消极的环境影响。更广泛的影响包括学生培训以及通过开发农业和能源的在线课程以及针对包括部落学校在内的偏远农村地区的教师的其他努力，对K-12教师进行培训。