Coincidence of Dynamical Transitions in a Soluble Protein and Its Hydration Water: Direct Measurements by Neutron Scattering and MD Simulations

The coupling between protein dynamics and hydration-water dynamics was assessed by perdeuteration, temperature-dependent neutron scattering, and molecular dynamics simulations. Mean square displacements of water and protein motions both show a broad transition at 220 K and are thus coupled. In particular, the protein dynamical transition appears to be driven by the onset of hydration-water translational motion.