title: The Effect of Tethers on Artificial Cell Membranes: A Coarse-Grained Molecular Dynamics Study.
abstract: Tethered bilayer lipid membranes (tBLMs) provide a stable platform for modeling the dynamics and order of biological membranes where the tethers mimic the cytoskeletal supports present in biological cell membranes. In this paper coarse-grained molecular dynamics (CGMD) is applied to study the effects of tethers on lipid membrane properties. Using results from the CGMD model and the overdamped Fokker-Planck equation, we show that the diffusion tensor and particle density of water in the tBLM is spatially dependent. Further, it is shown that the membrane thickness, lipid diffusion, defect density, free energy of lipid flip-flop, and membrane dielectric permittivity are all dependent on the tether density. The numerically computed results from the CGMD model are in agreement with the experimentally measured results from tBLMs containing different tether densities and lipids derived from Archaebacteria. Additionally, using experimental measurements from Escherichia coli bacteria and Saccharomyces Cerevisiae yeast tethered membranes, we illustrate how previous molecular dynamics results can be combined with the proposed model to estimate the dielectric permittivity and defect density of these membranes as a function of tether density.
authors.affiliation: Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: William
authors.initials: W
authors.lastname: Hoiles
authors.affiliation: Department of Electrical and Computer Engineering, The University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Rini
authors.initials: R
authors.lastname: Gupta
authors.affiliation: Director of Science and Technology, Surgical Diagnostics Pty Ltd., Unit 6 30-32 Barcoo Street, Roseville, New South Wales, 2069, Australia.
authors.forename: Bruce
authors.initials: B
authors.lastname: Cornell
authors.affiliation: School of Life Sciences, University of Technology Sydney, Broadway, New South Wales, Australia.
authors.forename: Charles
authors.identifier: http://orcid.org/0000-0003-3608-5440
authors.initials: C
authors.lastname: Cranfield
authors.affiliation: Electrical and Computer Engineering, Cornell University, New York, New York, United States of America.
authors.forename: Vikram
authors.initials: V
authors.lastname: Krishnamurthy
mesh_terms: D004058:Diffusion; D004926:Escherichia coli / Q000737:chemistry / Q000166:cytology; D008051:Lipid Bilayers / Q000737:chemistry*; D008567:Membranes, Artificial; D056004:Molecular Dynamics Simulation; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000166:cytology; D013816:Thermodynamics
chemical_list: D008051:Lipid Bilayers; D008567:Membranes, Artificial