Molecular dynamics of disaccharides by inelastic light scattering

The remarkable effectiveness of trehalose as a wide-range bioprotectant is a key issue in current studies of disaccharides hydration and dynamics. We are using INS (time-of-flight spectrometer IN6 at ILL) to compare the inelastic scattering from slightly hydrated trehalose with that of sucrose, a structurally similar but less effective disaccharide. The INS spectra of both disaccharides reveal several distinct excitations in the energy range 100-500 cm(-1). We identify a number of modes by comparison with density-functional computations of harmonic vibrational spectra. The possible biophysical implications of the differences in spectral properties are discussed