Professor Arieh Warshel
Department of Chemistry
USC
Los Angeles, CA

Monday, April 19, 2004
3:00 pm (CT)
3269 Beckman Institute

Abstract

Biological systems were optimized by evolution to reach a maximum overall efficiency. However, the available structural and biochemical information do not allow one to determine what are the most important catalytic mechanisms. It is, in fact, clear now that many proposed factors could not be used by evolution in optimizing enzyme catalysis. This talk will demonstrate the power of computer-based structure-function correlation in elucidating the source of the catalytic power of enzymes. Several major proposals will be examined. It will also be shown that ground state destabilization effects do not play a major role in enzyme catalysis, the analysis will include also the entropy proposal, the so- called "near attack conformation" proposal and the desolvation proposal. It will be shown furthermore that enzymes do not work by dynamical effects. Finally, It will be illustrated that enzymes work by using their pre-organized polar environment to stabilize the transition state of the reacting substrates. This means that enzyme catalysis is due to enzyme-enzyme interaction and not to enzyme-substrate interaction.

Tea and coffee will be served in R3151 Beckman Institute at 2:15pm.