Time Resoved Vibration Spectrocopy of Functioning Substrate-Bound Nitrogenase

无机，生物无机和有机化学计划的这一奖项支持加州大学滨江的Stephen P. Cramer教授通过使用时间分辨红外（TR-IR）光谱和相关技术阐明固氮酶的原子级机制。固氮酶生物化学和TR-IR光谱学的最新进展为确定大气中的氮气生物还原为土壤中可用于植物生长的氨的化学基础提供了前景。 具体目标是用途：1）TR-IR光谱法在周转条件下对MoFe固氮酶的底物结合形式进行物种形成。2)红外动力学，以探讨钼铁固氮酶的机制，特别是在关键氨基酸残基和高柠檬酸在周转过程中的变化。3)太赫兹（远红外）光谱研究与MoFe：Fe蛋白质复合物形成相关的构象模式。 功能固氮酶的红外动力学将被用来探测机制方面，如质子易位，蛋白质构象的变化伴随着能量消耗ATP水解，和形成和分解的固氮酶蛋白复合物在酶营业额。这项研究的更广泛的影响包括：1）通过使用加州戴维斯大学、犹他州州立大学、中央佛罗里达大学和劳伦斯伯克利国家实验室的先进设施以及ALS、伯克利和杰斐逊实验室的同步辐射仪器来促进教学、培训和学习。2)制定一项方案，通过暑期实习让代表性不足的群体（少数民族和残疾人）参与高中教育。3)通过建立独特的科学仪器（TR-IR低容量装置）和广泛的合作，建立研究和教育基础设施。

This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports Professor Stephen P. Cramer at the University of California at Riverside to elucidate the atomic-level mechanism of the nitrogenase enzyme by using time-resolved infra-red (TR-IR) spectroscopy with related techniques. Recent advances in nitrogenase biochemistry and TR-IR spectroscopy offer the prospect of determining the chemistry underpinning biological reduction of nitrogen gas in the atmosphere to ammonia available in soils for plant growth. Specific aims are to use: 1) TR-IR spectroscopy to speciate substrate bound forms of MoFe nitrogenase under turnover conditions. 2) IR kinetics to probe the mechanism of MoFe nitrogenase, particularly with regard to changes in key amino-acid residues and homocitrate during turnover. 3) Terahertz (Far-IR) spectroscopy to study the conformation modes associated with MoFe:Fe protein complex formation. IR kinetics of functioning nitrogenase will be used to probe mechanistic aspects such as proton translocation, changes in the protein conformational concomitant with the energy consuming ATP hydrolysis, and formation and dissociation of the nitrogenase protein complex during enzyme turnover. The broader impacts of this research include: 1) Promoting teaching, training and learning by using state of the art facilities at the University of California Davis, Utah State University, the University of Central Florida and Lawrence Berkeley National Laboratory as well as synchrotron radiation instrumentation at the ALS, Berkeley and Jefferson Laboratory. 2) Establishing a program to involve underrepresented groups (ethnic and disabled) at the high school level through summer internships. 3) The establishment of infrastructure for research and education through both the establishment of unique scientific instrumentation (the TR-IR low volume apparatus) and wide ranging collaborations.