A Brownian dynamics simulation of an acyl chain and a trans-parinaric acidmolecule confined in a phospholipid bilayer in the gel and liquid-crystal phases

A Brownian dynamics simulation of a saturated 16 C atom acyl chain, in a en vironment that reproduces a phospholipid bilayer in the gel phase, is prese nted. 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, equili brium 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 widel y used to probe the existence of lateral domains in phospholipid bilayers. The results of this simulation confirm the peculiar behavior of trans-parin aric acid when it is placed in different environments and reinforce the val idity of the Brownian dynamics technique to simulate membrane model systems .