Events & Seminars > Event Details


4pm, Room 304, Chemistry Building

Radical Involvement in Enzyme Catalysis – Professor Gary Gerfen


Professor Gary Gerfen
Albert Einstein College of Medicine

Hosted by: Professors Linda Columbus and Bob Nakamoto

Professor Gerfen’s webpage.

Abstract:  “Radical Enzymes” utilize amino acid based radical species to catalyze reactions which would be difficult to achieve using two-electron chemistry.  The enzymes use a variety of metals, either as endogenous ligands or as bound cofactors, to generate radicals.  Identification of these radical species is necessary to obtain a complete understanding of enzyme function, including the determination of catalytic and inhibition mechanisms.  Studies will be presented in which radicals from a variety of enzyme systems are identified and characterized, and their involvement in enzyme function will be discussed.   Systems for which radical intermediates have been investigated include Lactobacillus leichmannii ribonucleoside triphosphate reductase (RTPR), prostaglandin H2 synthase (PGHS), Mycobacterium tuberculosis catalase-peroxidase (KatG), and bovine cytochrome c oxdiase (bCcO).  The talk will highlight recent results obtained for CcO in which two tyrosyl radicals have been identified – one of these is the post-translationally cross-linked tyrosine-histidine species ligated to copper in the active site.  A new model for the proton pumping mechanism in bCcO using these radical species will be discussed.