ADVANCED EPR STUDIES OF RADICALS IN BIOLOGICAL CATALYSIS

生物催化中自由基的高级 EPR 研究

• 批准号: 2415356
• 负责人: JOHN L MCCRACKEN
• 金额: $ 15.1万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-05-01 至 1999-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2415356
• 关键词: active sites; amine oxidase (copper); carbon monoxide; electron spin resonance spectroscopy; free radicals; methylamines; oxidoreductase

DESCRIPTION: The long range objectives of the research proposed in this application are to understand the catalytic mechanisms of several enzymes by using advanced electron paramagnetic resonance (EPR) spectroscopic methods to probe the detailed electronic structure of their catalytic sites and to gain an understanding of how these systems control chemical reactivity. The enzymes to be studied are copper-containing amine oxidases, methylamine dehydrogenases, methylmalonyl Coenzyme A Mutase, and carbonmonoxide dehydrogenase. All of these proteins catalyze reactions that involve paramagnetic intermediate states at some point during their cycle. This work will involve further development and use of pulsed and double resonance EPR experiments to measure magnetic and electronic interactions between the unpaired electron spin of the transient paramagnetic species and the magnetic nuclei that comprise their environment. Such hyperfine couplings provide a direct measurement of the highest occupied molecular orbital of the paramagnetic center and thus yield information on the valence electron distribution that is involved in catalysis. Such information is difficult or impossible to obtain by other spectroscopic methods and by X-ray crystallography. Such information will be correlated with the results of kinetic and other structural measurements. In particular the results will be related to electron transferring oxidation/reduction processes.

描述：本研究提出的长期目标 应用是了解几种酶的催化机制 通过使用先进的电子顺磁共振（EPR）光谱 探测其催化的详细电子结构的方法 站点并了解这些系统如何控制化学品 反应性。 所研究的酶是含铜胺 氧化酶、甲胺脱氢酶、甲基丙二酰辅酶 A 变位酶、 和一氧化碳脱氢酶。 所有这些蛋白质都催化 在某个时刻涉及顺磁中间态的反应 在他们的周期中。 这项工作将涉及进一步的开发和使用 脉冲和双共振 EPR 实验测量磁和 不成对电子自旋之间的电子相互作用 瞬态顺磁性物质和组成的磁核 他们的环境。 这种超精细耦合提供了直接测量 顺磁中心的最高占据分子轨道和 因此产生有关价电子分布的信息 参与催化作用。 此类信息很难或不可能 通过其他光谱方法和X射线晶体学获得。这样的 信息将与动力学和其他结果相关 结构测量。 特别是，结果将与 电子转移氧化/还原过程。