One-particle-thick, Solvent-free, Course-grained Model for Biological and Biomimetic Fluid Membranes

Biological membranes are involved in numerous intriguing biophysical and biological cellular phenomena of different length scales, ranging from nanoscale raft formation, vesiculation, to microscale shape transformations. With extended length and time scales as compared to atomistic simulations, solvent-free coarse-grained membrane models have been exploited in mesoscopic membrane simulations. In this study, we present a one-particle-thick fluid membrane model, where each particle represents a cluster of lipid molecules. The model features an anisotropic interparticle pair potential with the interaction strength weighed by the relative particle orientations. With the anisotropic pair potential, particles can robustly self-assemble into fluid membranes with experimentally relevant bending rigidity. Despite its simple mathematical form, the model is highly tunable. Three potential parameters separately and effectively control diffusivity, bending rigidity, and spontaneous curvature of the model membrane. As demonstrated by selected examples, our model can naturally simulate dynamics of phase separation in multicomponent membranes and the topological change of fluid vesicles. Disciplines Engineering | Materials Science and Engineering Comments Suggested Citation: Yuan, H., C. Huang, J. Li, G. Lykotrafitis and S. Zhang. (2010). "One-particle-thick, solvent-free, coarsegrained model for biological and biomimetic fluid membranes." Physical Review E. Vol 82, 011905. © 2010 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Physical Review E and may be found at http://dx.doi.org/10.1103/ PhysRevE.82.011905. This journal article is available at ScholarlyCommons: http://repository.upenn.edu/mse_papers/182 One-particle-thick, solvent-free, coarse-grained model for biological and biomimetic fluid membranes Hongyan Yuan, Changjin Huang, Ju Li, George Lykotrafitis, and Sulin Zhang* Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, USA Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA Department of Mechanical Engineering, University of Connecticut, Storrs, Connecticut 06269, USA Received 18 March 2010; published 12 July 2010 Biological membranes are involved in numerous intriguing biophysical and biological cellular phenomena of different length scales, ranging from nanoscale raft formation, vesiculation, to microscale shape transformations. With extended length and time scales as compared to atomistic simulations, solvent-free coarse-grained membrane models have been exploited in mesoscopic membrane simulations. In this study, we present a one-particle-thick fluid membrane model, where each particle represents a cluster of lipid molecules. The model features an anisotropic interparticle pair potential with the interaction strength weighed by the relative particle orientations. With the anisotropic pair potential, particles can robustly self-assemble into fluid membranes with experimentally relevant bending rigidity. Despite its simple mathematical form, the model is highly tunable. Three potential parameters separately and effectively control diffusivity, bending rigidity, and spontaneous curvature of the model membrane. As demonstrated by selected examples, our model can naturally simulate dynamics of phase separation in multicomponent membranes and the topological change of fluid