A Brownian Dynamics Simulation of an Acyl Chain and a trans-Parinaric Acid Molecule Confined in a Phospholipid Bilayer in the Gel and Liquid-Crystal Phases

Abstract

A Brownian dynamics simulation of a saturated 16 C atom acyl chain, in a environment that reproduces a phospholipid bilayer in the gel phase, is presented. The simulation was performed using simple mean-field potentials, and the results were compared with experimentally obtained results for similar phospholipid acyl chains. With the appropriate choice of parameters, equilibrium and dynamical properties are recovered from our simulations and they present excellent agreement with experimentally determined values. We also performed a simulation of trans-parinaric acid, a fatty acid molecule widely used to probe the existence of lateral domains in phospholipid bilayers. The results of this simulation confirm the peculiar behavior of trans-parinaric acid when it is placed in different environments and reinforce the validity of the Brownian dynamics technique to simulate membrane model systems.