The molecular dynamics of aqueous solutions of a model amphiphilic peptide is studied as a function of concentration by broad-band light scattering experiments. Similarly to protein aqueous solutions, a considerable retardation, of about a factor 6-8, of hydration water dynamics with respect to bulk water is found, showing a slight dependence on solute concentration. Conversely, the average number of water molecules perturbed by the presence of peptide, i.e. the hydration number, appears to be strongly modified by adding solute. Its behaviour, progressively decreasing on increasing concentration, can be interpreted only considering the random close-to-contact condition experienced by solute particles. Overall, the present findings support the view of a "long range" effect of peptide on the surrounding water molecules, extending beyond the first two hydration shells.

Concentration dependence of hydration water in a model peptide

PAOLANTONI, Marco;SASSI, Paola;COREZZI, Silvia;MORRESI, Assunta;FIORETTO, Daniele
2014

Abstract

The molecular dynamics of aqueous solutions of a model amphiphilic peptide is studied as a function of concentration by broad-band light scattering experiments. Similarly to protein aqueous solutions, a considerable retardation, of about a factor 6-8, of hydration water dynamics with respect to bulk water is found, showing a slight dependence on solute concentration. Conversely, the average number of water molecules perturbed by the presence of peptide, i.e. the hydration number, appears to be strongly modified by adding solute. Its behaviour, progressively decreasing on increasing concentration, can be interpreted only considering the random close-to-contact condition experienced by solute particles. Overall, the present findings support the view of a "long range" effect of peptide on the surrounding water molecules, extending beyond the first two hydration shells.
2014
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11391/1221295
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