Dr. Wouter Hoff
Department of Microbiology an Molecular Genetics
Oklahoma State University
Stillwater, OK

Monday, December 6, 2010
3:00 pm (CT)
3269 Beckman Institute

Abstract

Proteins consist of only 20 different amino acids with very modest chemical reactivity, but perform a breathtaking range of functions. A central question in biophysics is to understand how proteins are able to achieve such functional versatility. Intramolecular interactions at the active site of proteins are critical for addressing this question. Functionally important side chains and cofactors at the active site of proteins often have properties that are strongly shifted from their values in water. Two classic examples of such functional tuning are (i) shifts in pKa value for proton transfer in processes such as acid-base catalysis and proton pumping, and (ii) shifts in absorbance maximum for spectral tuning in photoreceptors and color vision. In order to explore these issues we are developing and applying high-throughput protein spectroscopic techniques to the model system photoactive yellow protein. This work has resulted in a novel model for spectral tuning based on changes in the shape of the energy surfaces involved, and has revealed that proteins combine robustness against mutations with a high degree of evolvability. A key next step is to obtain a quantitative understanding of these data using computational approaches.