title: Lateral and transverse diffusion in two-component bilayer membranes.
abstract: We study the lateral and transverse diffusion of amphiphiles in two-component bilayer membranes, using a coarse-grained model for amphiphilic molecules and combined Monte Carlo-Molecular Dynamics simulations. Membrane structural properties, such as the mean thickness, are also measured. The dependence of such properties on membrane composition, inter-molecular interactions, and amphiphile stiffness is determined. In particular, we show that addition of shorter amphiphiles drives the model membrane towards a more fluid state, with increased amphiphile lateral diffusion rates. These results can be understood in the framework of a simple free-volume model. Furthermore, we observe an increase in the trans-membrane diffusion when the interaction energy of amphiphiles with their neighboring molecules is decreased.
authors.affiliation: Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Abteilung Theorie, D-14424 Potsdam, Germany. imparato@,pikg-golm.mpg.de
authors.forename: A
authors.initials: A
authors.lastname: Imparato
authors.forename: J C
authors.initials: JC
authors.lastname: Shillcock
authors.forename: R
authors.initials: R
authors.lastname: Lipowsky
mesh_terms: D001692:Biological Transport / Q000502:physiology; D003198:Computer Simulation; D004058:Diffusion; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D016062:Porosity; D015203:Reproducibility of Results; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry* / Q000378:metabolism; D014867:Water / Q000737:chemistry* / Q000378:metabolism
chemical_list: D008051:Lipid Bilayers; D008565:Membrane Proteins; D013501:Surface-Active Agents; D014867:Water