SGER: Constructing Functional Proton Wires

University Of Louisville Research Foundation Inc, Louisville KY

Investigators

Abstract

This Small Grant for Exploratory Research (SGER) in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Dr. Robert M. Buchanan at the University of Louisville to investigate one-dimensional proton wires. Proton transport is essential in biological systems and seeems likely to become increasingly important in other applications. In order to gain a better understanding of factors controlling the stabilization of continuous single file water chains in membranes and to develop functional models of proton wires, the properties of a new class of hydrated imidazole compounds that stabilize one-dimensional water chain structures will be investigated. The hydrated compounds will be characterized by a variety of methods including X-ray crystallography, IR, TGA, DSC, and solid-state NMR spectroscopy. Conductance of samples will be studied by impedance methods. The dynamic motion of the water chains will be studied using deuterium-exchanged samples at various temperatures by solid-state NMR spectroscopy. The water exchange process and dynamic motion of oxygen atoms within the channels will be studied using 17O-NMR spectroscopy. Molecular dynamics simulations will be performed on fragments of the water channel structures to study proton (deuterium) mobility along the water chains, and to establish the presence and nature of the charge species involved in proton translocation. Donor-acceptor properties of the water channels will be examined using pH-sensitive organic compounds, amino acids, peptides and proteins. This work is designed to provide a fundamental understanding of intermolecular water interactions relating proton/water mobility to ion/electron transfer. This project complements the U of Louisville's NSF-EPSCoR- supported Structural Biology Initiative and is potentially beneficial to the economic development of the Commonwealth of Kentucky. In addition, the proposed project will contribute to the development of an emerging research environment in biochemistry and structural biology targeting regional students who ultimately will contribute to the economic development of the state