Water in biological membranes at interfaces: does it play a functional role?

the purpose of this review is to examine and discuss the ways in which water is organized at the interface of a biological membrane. the relevance of this structure to the surface properties and to the adsorption of proteins in membranes is also analized. the approach is based on the idea that cell functions are confined to a restricted water media, the cell interior, in which the proximity of the membrane may bekey to regulating the enzyme activity and the cell membrane permeability. as the lipid bilayer is the structural base ofcell membranes, the distribution of water in the surface sites of a phospholipid membrane is analyzed by means of fourier transform spectrometry. the polarization of water at the surface was looked into through the measure ofsurface potentials and the dynamics of the surface hydration by cyclic voltammetry. modification of these properties by the replacement of water bypolyol molecules such as trehalose and phloretin and by the insertion of aqueous soluble enzymes, has also been investigated.