Structural and thermodynamic properties of water-membrane interphases: significance for peptide/membrane interaction

DISALVO, E ANIBAL; F. MARTINI; A. M. BOUCHET; HOLLMANN, AXEL; FRÍAS, M DE LOS 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 with membranes  of  different  lipid  composition.  In  this review,  how water modulates  the  interaction  of  peptides  and  proteins with  lipid membranes  is  discussed  by  correlating  the  thermodynamic  response  and  the structural changes of water at the membrane interphases.  The  thermodynamic  properties  of  the  lipid-protein  interaction  are  governed  by changes in the water activity of monolayers of different lipid composition according to  the  lateral  surface pressure.  In  this  context, different water populations  can be characterized below and above  the phase  transition  temperature  in relation  to  the CH2 conformers´ states in the acyl chains.  According  to  water  species  present  at  the  interphase,  lipid  membrane  acts  as  a water  state  regulator,  which  determines  the  interfacial  water  domains  in  the surface. It is proposed that those domains are formed by the contact between lipids themselves  and  between  lipids  and  the water  phase, which  are  needed  to  trigger adsorption-insertion  processes.  The  water  domains  are  essential  to  maintain functional  dynamical  properties  and  are  formed  by  water  beyond  the  hydration shell  of  the  lipid  head  groups.  These  confined  water  domains  probably  carries information in local units in relation to the lipid composition thus accounting for the link between lipidomics and aquaomics. The analysis of these results contributes to a  new  insight  of  the  lipid  bilayer  as  a  non-autonomous,  responsive  (reactive) structure that correlates with the dynamical properties of a living system.