Monte Carlo calculations of the free-energy landscape of vesicle formation and growthS.-J. Zhao and J. T. Kindt
Department of Chemistry, Emory University - Atlanta, GA, 30322, USA
received 25 August 2004; accepted in final form 7 January 2005
published online 4 February 2005
A flat-histogram Monte Carlo sampling method is used to calculate the free-energy landscape of a simple semi-flexible triangulated membrane model as a function of the number of vertices and the number of free edges. Results yield the equilibrium ratio of open (disk) and closed (vesicle) states, the free-energy barrier between these states, and the scaling of vesicle free energy with size N in the range from 6 to 200 vertices. Deviations from the predictions of a simple model for the disk-vesicle transition are found to result from the fluctuations of the edge. Vesicle free energies are fit to the form , with coefficient for flexible membranes (consistent with self-avoiding branched polymer statistics) and for semiflexible membranes.
87.16.Dg - Membranes, bilayers, and vesicles.
87.15.Aa - Theory and modeling; computer simulation.
© EDP Sciences 2005