Spatial dependence of protein-water collective hydrogen-bond dynamics.

Using molecular dynamics simulations, we analyze collective vibrations in the hydration water of a small globular protein. We develop tools that allow spatial resolution of correlated protein and water motion, and use them to reveal correlated vibrations that extend up to 10 Å from the protein surface at far-infrared/THz frequencies that are sensitive to the chemical properties of the protein surface. Our results provide the first detailed description of long-range effects on protein hydration water dynamics and highlight the differences between single particle and collective dynamics, which are relevant in interpreting experimental observations.