Interfacing molecular dynamics and macro-scale simulations for lipid bilayer vesicles.
A continuum-level model for a giant unilamellar vesicle (GUV) is bridged to a corresponding atomistic model of a dimyristoylphosphatidylcholine (DMPC) bilayer at various cholesterol concentrations via computation of the bulk modulus. The bulk modulus and other microscopically determined parameters are passed to a continuum-level model operating in time- and length-scales orders of magnitude beyond that which is accessible by atomistic-level simulation. The continuum-level simulation method used is the material point method (MPM), and the particular variation used here takes advantage of the spherical nature of many GUVs. An osmotic pressure gradient due to a solvent concentration change is incorporated into the continuum-level simulation, resulting in osmotic swelling of the vesicle. The model is then extended to treat mixtures of DMPC and cholesterol, where small domains of different composition are considered.
Department of Chemistry and Henry Eyring Center for Theoretical Chemistry, University of Utah, Salt Lake City, Utah 84112 USA.
Gary
G
Ayton
Alexander M
AM
Smondyrev
Scott G
SG
Bardenhagen
Patrick
P
McMurtry
Gregory A
GA
Voth
D000465:Algorithms; D055592:Biophysical Phenomena; D001703:Biophysics; D002244:Carbon / Q000737:chemistry; D002784:Cholesterol / Q000737:chemistry; D003198:Computer Simulation; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry*; D008566:Membranes / Q000737:chemistry; D015233:Models, Statistical; D009995:Osmosis; D017434:Protein Structure, Tertiary; D013997:Time Factors
D008051:Lipid Bilayers; D002244:Carbon; D002784:Cholesterol; D004134:Dimyristoylphosphatidylcholine