RUI: Infrared Spectroscopy as a Probe of Molecular Mechanismin the Hydrogenases

9723828巴格利低温红外差示光谱将用来描述氢酶中氢结合和激活的分子机制。先前对NiFe氢酶的红外光谱研究表明，这类酶显示出异常的、强烈的红外谱带，来自与活性中心Fe离子配位的一个本征一氧化碳分子和两个本征氰化物分子。这些异常的红外特征将被用于进一步研究酶的各种氧化还原状态；探索用红外光谱检测到的NiFe和Fe氢酶活性部位的相似性的性质；确定NiFe和Fe氢酶中一氧化碳结合的性质；以及研究氨基酸在氢的活化中所起的作用。这项工作的总体目标是了解氢酶将分子氢分解为质子和电子的能力背后的机制。了解这一过程对开发用于氢气生产和燃料电池的廉价和稳定的催化剂具有重要意义。此外，本研究所要求的在严格厌氧条件下处理红外样品的方法的发展应被证明在其他对氧敏感的金属蛋白的红外研究中具有普遍的实用性。这项研究将有本科生参与。参与这个项目将为本科生提供一个独特的机会，应用他们到目前为止学到的技能和知识，同时为现代物理生物化学的项目做出贡献。***

9723828 Bagley Low temperature infrared difference spectroscopy will be used to delineate the molecular mechanism of hydrogen binding and activation in hydrogenases. Previous infrared spectroscopic studies on the NiFe hydrogenases have shown that this class of enzymes display anomalous, intense infrared bands arising from one intrinsic carbon monoxide molecule and two intrinsic cyanide molecules coordinated to the active site Fe ion. These anomalous infrared signatures will be used for further study of the various redox states of the enzyme; for exploration of the nature of the similarities in the active sites of the NiFe and Fe hydrogenases as detected using infrared spectroscopy; determination of the nature of carbon monoxide binding in the NiFe and Fe hydrogenases; and examination of the role amino acids play in the activation of hydrogen. The overall goal of this work is to understand the mechanism underlying the hydrogenases' ability to split molecular hydrogen into protons and electrons. Understanding this process has important consequences for the development of cheap and stable catalysts for use in hydrogen production and fuel cells. In addition, the development of methodologies for handling infrared samples under strictly anaerobic conditions as required in this research should prove of general utility in infrared studies of other oxygen sensitive metallo-proteins. The research will involve participation of undergraduate students. Participation in this project will afford undergraduate chemistry students a unique opportunity to apply skills and knowledge they have learned so far while contributing to a project in modern physical biochemistry. ***