Abstract
Trehalose is known to act as a protectant against various environmental stresses, including drying, freezing, oxidation, ethanol stress, osmotic stress and so on. In this review, we discuss the origin of such a function of trehalose based on its hydration property. First, we summarize the solution properties of trehalose obtained from a variety of physicochemical measurements. Second, several results of recent computer simulations are described to provide atomistic level picture of the hydration property of this sugar. It is noted that trehalose has a highly anisotropic hydration shell, and thus it has amphiphilic nature, which allows complex formation not only with hydrophilic molecules but also with hydrophobic ones. Third, we describe our recent study showing that trehalose can form a stable intermolecular complex with benzene in aqueous solution. On the basis of this result, we propose a new mechanism for the inhibition effect of trehalose on aggregation of β-amyloid. Finally, it is stressed that the origin of these unique functions of trehalose is ascribed to the structural peculiarity of this sugar, that is, the presence of rigid α,α-1,1 glycosidic bond.
