Comparison of Ruthenium-Based Photoinitiators for the Study of Electron Transfer in Metalloproteins

by Dossey, Ryan Wayne; Durham, Bill; Millett, Francis Spencer

Ruthenium polypyridine complexes have been shown to be exceptional photoinitiators in the study of electron transfer in metalloproteins such as those involved in mitochondrial respiration. Reactions of cytochrome c with cytochrome c oxidase and the bc1 complex are among the recent examples. Many complexes have been employed in these investigations, but there has not been a detailed study that compares the overall efficiencies of these complexes. In this poster, we will describe a comparison of the relative reaction rates and over all efficiencies for a series of six complexes all derived from the parent Ru(bpy)32+. In addn., we will compare the labeling efficiencies of these complexes, two of which rely on the reaction of an alpha bromomethylbipyridine with the sulfur of surface cystiene residues and the remaining four by reaction of the maleimide deriv. of 5-amino-1,10-phenanthroline. The summary of these expts. will allow a ruthenium complex to be selected to suit the properties of a given protein.