Examining enzyme active site dynamics using linear and nonlinear infrared spectroscopy: substrate orientation, cofactor composition, and solvent effects

Abstract

The active sites of enzymes undergo motions spanning a broad range of timescales but the role of dynamics in catalysis is still unknown. We apply linear and nonlinear infrared spectroscopic techniques, combined with site-specific vibrational labeling, to gain insights into the ultrafast dynamics of the active site as a function of orientation of the substrate, composition of the active site, and the presence of cosolvents in the solution. We are examining these phenomena in three model enzymes bound to vibrationally labeled substrate analog probes.