Bridging molecular simulation models and elastic theories for amphiphilic membranes

The Single Chain Mean Field theory is used to link coarse-grained models of amphiphilic molecules with analytical models for membrane elasticity, where phenomenological parameters are deduced from explicit molecular models and force fields. We estimate the elastic constants based on the free energy of the amphiphilic bilayer in planar and cylindrical geometries on the example of four amphiphilic molecules that differ in length and stiffness. We study how these variations affect the equilibrium bilayer structure, the equilibrium free energy, and the elastic constants. Bending rigidities are obtained within the typical range of experimental values for phospholipid membranes in a liquid state.