Intermolecular electron transfer reactions of cytochrome c on gold nanoparticles

INOR 766

Adrienne Carver, agilbert@chem.umass.edu and Michael J. Knapp, mknapp@chemistry.umass.edu. Department of Chemistry, University of Massachusetts at Amherst, 710 North Pleasant Street, Amherst, MA 01003
The dynamics of surface recognition and binding at the protein interface is a key component of intermolecular electron transfer (ET) reactions. This study probes how anionic gold nanoparticles enhance the ET reactivity of cytochrome c. Stopped-flow UV-Vis spectroscopy monitors the reaction of the protein-nanoparticle adduct with small redox reagents. The ET rate is affected by the surface properties of the nanoparticle, including charge, hydrophobicity, and the substituents. The rate constants are significantly attenuated by charge screening, suggesting that the nanoparticle promotes reactivity through preassembly of the reagents.