Tuning substrate selectivity in cytochrome c peroxidase though surface recognition by gold nanoparticle

INOR 503

Halil Bayraktar, bayrakta@chem.umass.edu1, Nicole Moorer2, Adrienne Carver, agilbert@chem.umass.edu1, Partha S. Ghosh, pghosh@chem.umass.edu3, Vincent M. Rotello, rotello@chem.umass.edu1, and Michael J. Knapp, mknapp@chemistry.umass.edu1. (1) Department of Chemistry, University of Massachusetts at Amherst, 710 North Pleasant Street, Amherst, MA 01003, (2) Department of Chemistry, North Carolina State University, NC 27695, (3) Department of Chemistry, University of Massachusetts Amherst, 710 North Pleasant Street, Amherst, MA 01003
The heme containing enzymes plays a key role for the delivery and activation of small molecules. Achieving control over enzyme active sites with nanoparticles may lead to novel biocatalysis and sensing. Here, we report the use of functionalized gold nanoparticles to control the substrate selectivity of cytochrome c peroxidase (CCP). The EPR and UV-VIS spectrum of oxoferryl (FeIV=O) cation radical in the nanoparticle:CCP hybrid is very similar to that seen in unbound CCP, indicating that compound I forms. Moreover, the gold nanoparticle inhibits the activity toward guaiacol and cytochrome c which reacts at a specific binding site on CCP. In contrast, the activities against non-specific substrates such as ferrocyanide and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) are not affected. The results indicate that the nanoparticle:CCP hybrid is catalytically competent, and that positioning of gold nanoparticle on the surface of CCP alters substrate selectivity.
 

Nanoscience - Characterization and Applications
9:00 AM-1:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 219, Oral

Division of Inorganic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008