Relationship between Fluctuations and Reactions of Proteins

Abstract

Biological molecules fluctuate at room temperature in solution, because of the thermal motion. A relationship between fluctuations and biological reactions should be clarified for understanding molecular mechanism of biological reactions. Some methods to detect protein fluctuations are reviewed. In particular, a recently developed time-resolved method to measure the fluctuations based on the transient grating is described. This method was applied to a reaction of a blue-light sensor protein TePixD. This result clearly demonstrated that the compressibility, which reflects the fluctuation is enhanced during the reaction. It was also found that this enhanced fluctuation is a trigger of the reaction, supporting the importance of fluctuations for the biological function.