Kinetics and Mechanisms of Oxygen and Peroxide Activation by Non-heme Iron Complexes

塔夫茨大学的Elena Rybak-Akimova在无机、生物无机和有机金属化学项目的支持下，对非血红素铁配合物的氧和过氧化物活化的动力学和机制进行了研究。她之前没有担任过NSF研究资助项目的首席研究员。该提案的一个主要目的是阐明涉及自由基的铁介导的生物氧化与通过“无自由基”途径进行的氧化之间的区别。三吡啶胺（TPA）配体支持的高价氧化铁将在低温下进行动力学和机理研究，使用低温停流技术（单次和双次混合），分光光度法和EPR配准。该项目的研究将澄清重要生化过程的模糊方面，并提供可能导致在化学合成和废物氧化解毒中使用氧和/或过氧化氢的无害环境过程的发展的见解。复杂的停流动力学研究，如这里提出的，是必要的，以证明酶活性位点的合成模型与实际生物功能的关系。现在很少有实验室有能力进行这种研究。该项目将为学生和博士后研究人员提供特别有价值的培训。

Elena Rybak-Akimova of Tufts University is supported by the Inorganic, Bioinorganic, and Organometallic Chemistry Program to conduct research on kinetics and mechanisms of oxygen and peroxide activation by non-heme iron complexes. She has not previously been PI of NSF research grants. A main aim of the proposal is to elucidate the difference between iron-mediated biological oxidations that involve free radicals and those that proceed through 'radical-free' pathways. Kinetic and mechanistic studies of high-valent iron oxo species supported by tris-picolyamine (TPA) ligands will be carried out at low temperatures, using cryogenic stopped-flow techniques (single and double mixing) with spectrophotometric and EPR registration. Research under this project will clarify obscure aspects of important biochemical processes and provide insights that potentially will lead to development of environmentally benign processes using oxygen and/or hydrogen peroxide in chemical synthesis and oxidative detoxification of wastes. Sophisticated stopped-flow kinetic studies, such as those proposed here, are necessary to demonstrate the relationship of synthetic models of enzyme active sites to actual biological function. Few laboratories now have the capability to carry out such studies. This program will provide especially valuable training for students and postdoctoral researchers.