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Article Dans Une Revue Journal of Physical Chemistry B Année : 2014

CHARMM36 united atom chain model for lipids and surfactants.

Sarah Lee
  • Fonction : Auteur
Alan Tran
  • Fonction : Auteur
Matthew Allsopp
  • Fonction : Auteur
Joseph B. Lim
  • Fonction : Auteur
Jeffery B. Klauda
  • Fonction : Auteur

Résumé

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 \textpm 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.
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Dates et versions

hal-01498054 , version 1 (29-03-2017)

Identifiants

Citer

Sarah Lee, Alan Tran, Matthew Allsopp, Joseph B. Lim, Jérôme Hénin, et al.. CHARMM36 united atom chain model for lipids and surfactants.. Journal of Physical Chemistry B, 2014, 118 (2), pp.547--556. ⟨10.1021/jp410344g⟩. ⟨hal-01498054⟩
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