It is well known that water is the medium in which the overwhelming majority of biological processes take place. In cell membranes water molecules are thought to be essential to not only the structure and stability of the membranes, but also to play a central role in membrane transport,1,2 where water molecules have been proposed to be integral to membrane recognition of soluble proteins in vivo.3 Even though water is widely acknowledged to be essential to these processes, the specific interactions between water and biological molecules still remain largely unknown.