CHARMM36 united atom chain model for lipids and surfactants.

Error message

Warning: A non-numeric value encountered in theme_biblio_tabular() (line 223 of /var/www/html/sites/all/modules/biblio/includes/biblio_theme.inc).
TitleCHARMM36 united atom chain model for lipids and surfactants.
Publication TypeJournal Article
Year of Publication2014
AuthorsLee S, Tran A, Allsopp M, Lim JB, Hénin J, Klauda JB
JournalJ. Phys. Chem. B
Volume118
Pagination547–556
Date Publishedjan
Keywordsanalogs /&/ derivatives/chemistry, chemistry, Cholesterol, Dimyristoylphosphatidylcholine, Lipid Bilayers, Lipids, Micelles, Molecular Dynamics Simulation, Phosphorylcholine, Surface-Active Agents
Abstract

Molecular simulations of lipids and surfactants require accurate parameters to reproduce and predict experimental properties. Previously, a united atom (UA) chain model was developed for the CHARMM27/27r lipids (Hénin, J., et al. J. Phys. Chem. B. 2008, 112, 7008-7015) but suffers from the flaw that bilayer simulations using the model require an imposed surface area ensemble, which limits its use to pure bilayer systems. A UA-chain model has been developed based on the CHARMM36 (C36) all-atom lipid parameters, termed C36-UA, and agreed well with bulk, lipid membrane, and micelle formation of a surfactant. Molecular dynamics (MD) simulations of alkanes (heptane and pentadecane) were used to test the validity of C36-UA on density, heat of vaporization, and liquid self-diffusion constants. Then, simulations using C36-UA resulted in accurate properties (surface area per lipid, X-ray and neutron form factors, and chain order parameters) of various saturated- and unsaturated-chain bilayers. When mixed with the all-atom cholesterol model and tested with a series of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)/cholesterol mixtures, the C36-UA model performed well. Simulations of self-assembly of a surfactant (dodecylphosphocholine, DPC) using C36-UA suggest an aggregation number of 53 ± 11 DPC molecules at 0.45 M of DPC, which agrees well with experimental estimates. Therefore, the C36-UA force field offers a useful alternative to the all-atom C36 lipid force field by requiring less computational cost while still maintaining the same level of accuracy, which may prove useful for large systems with proteins.

DOI10.1021/jp410344g
Citation Key2014|1669