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

Tufts University, Medford MA

Investigators

Abstract

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.