IQENS dynamics in hydrated Crambin

In this paper, we present a high-resolution Incoherent Quasi-elastic Neutron Scattering experiment on Crambin hydrated at h=0.6 g/g. Hydration was attained by using D2O and H2O, in order to separate the contribution of the protein from that of the water. The spectra were interpreted in terms of an elastic peak and a quasi-elastic Lorentzian contribution. From the obtained EISF, information about the number of fixed and mobile hydrogens are derived. For the latter, an estimation of the spanned spatial and temporal scales is provided. In the case of protein dynamics, the obtained results favorably compare with the literature data on the conformational disorder found by X-ray diffraction on the crystalline sample. In the case of water dynamics, the data show a confinement effect on the diffusion of hydration water.