Protein-trehalose-water structures in trehalose coated carboxy-myoglobin

Some organisms can survive complete dehydration and/or high temperature in a state of suspended animation called anydrobiosis, in which all metabolic processes are "switched off" however, upon rehydration, their normal life cycle is restored, without formation of irreversible damages. A common feature of these organisms, when in anhydrobiosis, is the presence of large amounts of sugar, particularly trehalose, which has been found to protect most effectively biomaterials. Several studies have attempted to understand how trehalose interacts with biomolecules. To address this problem, we performed molecular dynamics simulations of carboxy-myoglobin embedded in a trehalose aqueous solution and in a trehalose-water plasticized amorphous matrix. The results show that, in an aqueous solution, trehalose is excluded from the protein domain. This behavior extends also to the trehalose-water plasticized amorphous matrix, where we find sugar-water-protein structures with more water molecules that those derived from system concentration, and only few trehalose molecules bound to the protein, mainly through single hydrogen bonds. (C) 2002 American Institute of Physics.