Structural and thermodynamic properties of water?membrane interphases: Significance for peptide/membrane interactions

DISALVO E. A.; MARTINI, M. FLORENCIA; BOUCHET, ANA; HOLLMANN, AXEL; FRÍAS, M. A.

ADVANCES IN COLLOID AND INTERFACE SCIENCE.

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 211 p. 17 - 33

0001-8686

Water appears as a common intermediary in the mechanisms of interaction of proteins and polypeptides withmembranes of different lipid composition. In this review, how water modulates the interaction of peptides andproteins with lipid membranes is discussed by correlating the thermodynamic response and the structuralchanges of water at the membrane interphases.The thermodynamic properties of the lipid?protein interaction are governed by changes in the water activity ofmonolayers of different lipid composition according to the lateral surface pressure. In this context, differentwaterpopulations can be characterized below and above the phase transition temperature in relation to the CH2conformers´ states in the acyl chains.According to water species present at the interphase, lipid membrane acts as a water state regulator, whichdetermines the interfacial water domains in the surface. It is proposed that those domains are formed bythe contact between lipids themselves and between lipids and the water phase, which are needed to triggeradsorption?insertion processes. The water domains are essential to maintain functional dynamical propertiesand are formed by water beyond the hydration shell of the lipid head groups. These confined water domainsprobably carries information in local units in relation to the lipid composition thus accounting for the linkbetween lipidomics and aquaomics. The analysis of these results contributes to a new insight of the lipid bilayeras a non-autonomous, responsive (reactive) structure that correlates with the dynamical properties of a livingsystem.