Molecular dynamics simulation of lipid bilayers with GROMOS96: Application of surface tension

Abstract

The GROMOS96 force fields 45A3 and 53A5, when applied to dipalmitoylphosphatidylcholine (DPPC) membranes, have a tendency to result in a reduced area per lipid in constant pressure simulations. The application of surface tension is effective in increasing the area per lipid, a measure of the phase of the membrane, but only if the area is already close to the experimental range. Therefore the surface tension cannot compensate for strong inadequacies in the force-field parameters. The behaviour of the 45A3 force field from long NP _n γT simulations of tens of nanoseconds is analysed over a range of different surface tensions. Comparisons are made with the corresponding NP _n AT simulations.

Keywords:

• Molecular dynamics simulation
• GROMOS96
• DPPC
• Lipid bilayer membrane
• Surface tension

Acknowledgements

The authors wish to acknowledge the National Center for Competence in Research (NCCR) in Structural Biology and the Swiss National Science Foundation for financial support.