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.

拟议的工作涉及实施一个多学科的方法，使用基本的生物化学，光谱学和X射线晶体学技术，以探讨一些关键的悬而未决的问题有关的固氮，固氮酶的关键酶的机制。我们将探讨的假设，氧化还原依赖的结构变化是关键的调制中点电位和定义的门控分子间电子转移的P簇的作用。关键位点定向变体和铕络合物氧化还原介体的组合使用将有助于捕获与催化机制相关的酶的定义状态，这些状态在天然状态下是不可能观察到的，并且将回答关于底物与FeMo-辅因子结合的问题。生物固氮的基础研究有助于减少能源需求和更环保的机制，以满足与全球人口增长相关的固定氮日益增长的需求，因为植物生长的固定氮源的可用性是全球营养的限制因素，氮肥的生产对能源的需求非常高，可能对环境产生负面影响。更广泛的影响包括学生培训和通过开发农业和能源在线课程沿着针对包括部落学校在内的偏远农村地区教师的其他努力，为培训K-12教师做出重大贡献。