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Modification of the CHARMM force field for DMPC lipid bilayer
Author(s) -
Högberg CarlJohan,
Nikitin Alexei M.,
Lyubartsev Alexander P.
Publication year - 2008
Publication title -
journal of computational chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.907
H-Index - 188
eISSN - 1096-987X
pISSN - 0192-8651
DOI - 10.1002/jcc.20974
Subject(s) - chemistry , force field (fiction) , bilayer , lipid bilayer , scaling , structure factor , chemical physics , ab initio , surface tension , thermodynamics , computational chemistry , crystallography , physics , organic chemistry , mathematics , biochemistry , geometry , quantum mechanics , membrane
The CHARMM force field for DMPC lipids was modified in order to improve agreement with experiment for a number of important properties of hydrated lipid bilayer. The modification consists in introduction of a scaling factor 0.83 for 1–4 electrostatic interactions (between atoms separated by three covalent bonds), which provides correct transgauche ratio in the alkane tails, and recalculation of the headgroup charges on the basis of HF/6‐311(d,p) ab‐initio computations. Both rigid TIP3P and flexible SPC water models were used with the new lipid model, showing similar results. The new model in a 75 ns simulation has shown a correct value of the area per lipid at zero surface tension, as well as good agreement with the experiment for the electron density, structure factor, and order parameters, including those in the headgroup part of lipids. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008