An implicit solvent coarse-grained lipid model with correct stress profile.
We develop a coarse-grained parametrization strategy for lipid membranes that we illustrate for a dipalmitoylphosphatidylcholine bilayer. Our coarse-graining approach eliminates the high cost of explicit solvent but maintains more lipid interaction sites. We use a broad attractive tail-tail potential and extract realistic bonded potentials of mean force from all-atom simulations, resulting in a model with a sharp gel to fluid transition, a correct bending modulus, and overall very reasonable dynamics when compared with experiment. We also determine a quantitative stress profile and correct breakdown of contributions from lipid components when compared with detailed all-atom simulation benchmarks, which has been difficult to achieve for implicit membrane models. Such a coarse-grained lipid model will be necessary for efficiently simulating complex constructs of the membrane, such as protein assembly and lipid raft formation, within these nonaqueous chemical environments.
Department of Bioengineering, University of California, Berkeley, Berkeley, California 94720, USA.
Alex J
AJ
Sodt
Teresa
T
Head-Gordon
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000031:analogs & derivatives* / Q000737:chemistry*; D003198:Computer Simulation; D002523:Edible Grain; D008051:Lipid Bilayers / Q000737:chemistry*; D008055:Lipids / Q000737:chemistry; D008566:Membranes / Q000737:chemistry; D008958:Models, Molecular; D012997:Solvents; D013816:Thermodynamics
D008051:Lipid Bilayers; D008055:Lipids; D012997:Solvents; D015060:1,2-Dipalmitoylphosphatidylcholine; C081581:colfosceril palmitate