The vibrational dynamics of protein hydration water has been studied by incoherent neutron scattering. Experiments on a sample of fully deuterated maltose binding protein allowed us to single out the hydration water susceptibility. The main inelastic features, corresponding to hydrogen-bond bending, hydrogen-bond stretching and librational excitations, have been followed over a temperature range extending from 50 to 300 K. It turns out that the temperature dependence of the hydrogen-bond stretching contribution is quite similar to that of the mean square displacements deduced by the quasielastic signal, thus suggesting a close relationship between the anharmonicity of longitudinal phonon-like motions and the onset of diffusive molecular dynamics. On the other hand, both hydrogen-bond bending and librational excitations show a temperature dependence consistent with a harmonic character over the whole temperature range.
|Autori:||Paciaroni, Alessandro; Orecchini, Andrea; Sebastiani, Federico; Capaccioli, Simone; Ngai, Kia L.; Moulin, Martine; Haertlein, Michael; Petrillo, Caterina; Sacchetti, Francesco|
|Titolo:||Vibrational dynamics changes of protein hydration water across the dynamic transition|
|Anno del prodotto:||2015|
|Digital Object Identifier (DOI):||10.1016/j.jnoncrysol.2014.09.028|
|Appare nelle tipologie:||1.1 Articolo in rivista|