Calculation of membrane bending rigidity using field-theoretic umbrella sampling

Abstract

The free-energy change of membrane shape transformations can be small, e.g., as in the case of membrane bending. Therefore, the calculation of the free-energy difference between different membrane morphologies is a challenge. Here, we discuss a computational method - field-theoretic umbrella sampling - to compute the local chemical potential of a non-equilibrium configuration and illustrate how one can apply it to study free-energy changes of membrane transformations using simulations. Specifically, the chemical potential profile of the bent membrane and the bending rigidity of membrane are calculated for a soft, coarse-grained amphiphile model and the MARTINI model of a dioleoylphosphatidylcholine (DOPC) membrane. (C) 2015 AIP Publishing LLC.