Catalytic Peptide-PNA Based Bioinspired CompoundsJason Shearer, University of Nevada, Reno, NV 89557

The goal of this project is to prepare metal-complexes that can perform catalytic reactions. Specifically the the metal-centers will be contained within a bioinspired peptide-PNA scaffold. As an initial focus we have prepared a metallopeptide that contains a CoIII-center in an N2S3 coordination environment (Co is coordinated two amidate nitrogens, one cysteinate sulfur, one sulfenate sulfur and one sulfinate sulfur; see figure) that performs the conversion of nitriles to amides. Thus, the metallopeptide behaves similarly to the metalloenzyme nitrile hydratase. The turn over-numbers are low for activated nitriles like acrylonitrile (58 over 18 hours) and thus we will be improving the system in the future using using two approaches. One involves the use of PNA residues to enforce outersphere residues about the active site to aid in catalysis. The other is the craft the active-site on a solid support to effect heterogeneous catalysis of nitrile waste.

Computational model of the active CoNHase metallopeptide based model prepared in our lab (mPW-PW91; aug-cc-TZVPP)