Role of water in the responsiveness of lipid membranes: Application of non-equilibrium thermodynamics

Abstract

The phenomenological description of a lipid membrane within the frame of the interphase model in which membrane is a bidimensional solution of hydrated lipids allows to make compatible the membrane theory and Ling hypothesis by considering the physical chemical properties of the aqueous lipid interphase.The membrane suffers mechanical stress inducing changes in hydration and changes in composition. These conditions affect the amount of labile active water propense to response to bioeffectors. This behavior is properly described with the approach of thermodynamic of irreversible processes in which the membrane is an open system and is in a metastable state propense to react due to bioeffectors in the adjacent aqueous solution. In terms of this analysis, the hydration shell is inert to bioeffectors and the response of the membrane is given by the excess of water that is labile and osmotically exchangeable.