A Guiding Potential Method for Evaluating the Bending Rigidity of Tensionless Lipid Membranes from Molecular Simulation

S. Kawamoto, T. Nakamura, S. O. Nielsen and W. Shinoda

J. Chem. Phys. 139, 034108-1-10 (2013).

A new method is proposed to estimate the bending rigidity of lipid membranes from molecular dynamics simulations. An external cylindrical guiding potential is used to impose a sinusoidal deformation to a planar membrane. The bending rigidity is obtained from the mean force act- ing on the cylinder by calibrating against a discretized Helfrich model that accounts for thermal fluctuations of the membrane surface. The method has been successfully applied to a dimyristoyl phosphatidylcholine (DMPC) bilayer simulated with a coarse-grained model. A well-converged bending rigidity was obtained for the tension-free membrane and showed reasonable agreement with that obtained from the height fluctuation spectrum.