Comparative analysis of the hydration of model lipid membranes in gel and liquid crystalline phases: molecular dynamic simulations of DPPC bilayers

DANIEL E. RODRIGUES

Ciudad Autonoma de Buenos Aires

Workshop; Workshop “Water properties and its relevance in biological functions”; 2010

Fac. de Farmacia y Bioquimica - UBA

We have performed Molecular Dynamic simulations of hydrated DPPC bilayers in Gel and LC phases. The use of the same parametrization of the forcefield for both phases allows us to conduct a meaningful comparison between the result for the compact and the liquid aggregates. At variance with previous DPPC gel phase simulations which had been started from the crystalline coordinates, our initial structure were taken from the LC phase to avoid being trapped in local minima of the conformational space. We found that the number of H2O bound by HB to each lipid are 3.5 (G) and 4.1 (LC). The number of H2O per lipid polarized by the interface potential is 13.1 (G) and 22.2 (LC). We analyze such differences and their origin.