Phase Diagram of Lipid-Cholesterol Mixture: Comparison between Different Force Fields

Abstract

Molecular Dynamics simulations have shown to be a reliable tool for the understanding of biological processes at molecular level. The modelling of lipid bilayers with this technique is a common practice nowadays, leading to information on the behavior of such a complex systems. As in any other theoretical approach, validation regarding the experiments is required. In this work we analyse the behavior of different properties like thickness and lateral diffusion along the phase diagram of a mixture of POPC and cholesterol. We compare the results of different force fields (Berger, Charmm36 and Slipids) implemented in the GROMACS package. The results show the key role of the force field in the reproduction of the experimental behavior of the properties along the phase transitions. Only an ab-initio refined potential was able to do this.