Picosecond time scale solvent fluctuations and enzymatic regulation in hen egg white lysozyme ligand reactions

Abstract

Experimental THz experiments on hen egg-white lysozyme (HEWL) with and without the ligand NAG3 has revealed that the protein's solvent structure on the picosecond time scale is in integral part of the regulation mechanism of the enzyme. Our investigation into the low frequency dynamics of the protein has uncovered that the counterions in the solvent shell mediate the collective dynamics of both the water and the protein in the system. As a result, we find that the lysozyme fast dynamics is strongly influenced by fast water (H — bonding) dynamics. Both the activity and structure of the water change with addition of the ligand. Perhaps most intriguing is that we find that the long range correlation between distant parts of protein are broken with the addition of the inhibitor; which coincides with the disruption of energy dispersion in the solvent hydrogen bonding network.