Proteins are flexible molecules that continuously undergo structural fluctuations on time scales ranging from femtoseconds (10-15 sec) to seconds and longer. However, current strategies for controlling biochemical function focus exclusively on structure. My group is interested in learning how protein motions impact biochemistry and in using this knowledge to expand our repertoire of techniques for biochemical control.
Our research program employs techniques from biochemistry, chemical physics, and optics. We use femtosecond laser spectroscopy to measure protein motions. These lasers produce pulses of light shorter than most molecular motions, thus enabling laser "snapshots" of protein motion. The measurements quantify the spectrum of molecular motions by probing either the electronic transitions of a bound cofactor or ligand. Experiments on site-directed mutants or chemically modified proteins are used to determine the structural origins of the motions.