Study of trehalose effects on bsa solutions

Thermal stability of Bovine Serum Albumins (BSA) in trehalose water mixtures is investigated by InfraRed spectroscopy measurements carried out in the 400-4000 cm-1 frequency range. We found that trehalose shows effects on the hydrogen bond network of water and that it reduces the protein dynamic fluctuations thanks to the strengthening of the intermolecular O-H interactions in the hydrogen-bond network of solvent. The temperature behaviour of the spectral features of the BSA amide I band, connected with the dihedral angles of the various protein secondary structures, are analyzed in terms of both spectral difference and wavelet analyses. The two analyses provide sigmoidal temperature behaviours for the spectral difference and the wavelet cross coefficient. These s-shaped trends are characterized for the BSA in trehalose water mixtures, in respect to the BSA in water mixtures, by higher values of the inflection point temperatures together with higher thermal restraint values which clearly highlight a trehalose-induced increased stabilization.