Physics Colloquium, April 29, 2008
Ruling Proteins with Protons Aihua Xie

Oklahoma State University

Proteins are able to perform an enormous variety of biological functions, while using only a limited number of underlying principles. One of these is proton transfer, found in all forms of life, in a range of proteins performing biological signaling, energy transformation, and enzymatic catalysis. We employ photoactive yellow protein (PYP), a bacterial blue light sensor as a model system, to investigate the light-triggered proton movements in its active site. In my talk, I will show how the movement of a tiny proton causes large amplitude "protein quake" via an "electrostatic epicenter". As a result, PYP is transformed from the initial receptive state— "off-state", into the new signaling state — "on-state" for protein-protein communication and signal relay. In addition, I will discuss that our "electrostatic epicenter" model may be generalized to understand activation of other receptor proteins in cell signaling, including rhodopsin for vision.

Dr. Xie's Web Site

4:00 p.m., Physics Research Building (PRB), Room 1080

Reception at 3:45 p.m., Atrium, PRB