Influence of hydration and cation binding on parvalbumin dynamics

Due to structural characteristics, parvalbumin exerts a major role in intracellular Mg2+ and Ca2+ concentration regulation during the muscular contraction-relieving cycle. This structure-function relationship being established, we are investigating the structure-dynamics-function relationship to take into account the protein dynamics. Because of the strong incoherent neutron scattering cross section of hydrogen and of the abundance of this element in proteins, incoherent inelastic neutron scattering is a unique probe to study vibrations and localised motions in biological macromolecules. We take advantage of the complementarities in energy or time resolution of various neutron spectrometers (time of flight, backscattering, spin-echo) to probe the parvalbumin dynamics from a fraction of a picosecond to a few nanoseconds. Influences of hydration and of the nature of the cation on parvalbumin dynamics are discussed.