Water is widely assumed to be essential for protein dynamics and function. In particular, the well-documented "dynamical" transition at ~200 K detected in hydrogenated proteins by incoherent neutron scattering, at which the protein changes from a rigid, non-functional form to a flexible, functional state, requires hydration. Here, we report on coherent neutron scattering experiments on perdeuterated proteins and reveal that a transition occurs in dry proteins at the same temperature resulting primarily from the thermal activation of collective heavy-atom motions. The dynamical transition discovered is intrinsic to the energy landscape of dry proteins.
Citation: Physical Review Letters
Pub Type: Journals
Dynamical transition, protein, neutron scattering