Lipid14: The Amber Lipid Force Field.

Area of Science:

• Biochemistry
• Computational Chemistry
• Molecular Dynamics

Background:

• The accurate simulation of lipid bilayers is crucial for understanding cell membrane properties.
• Existing molecular dynamics force fields often require surface tension for accurate bilayer simulations.
• The AMBER force field is widely used for biomolecular simulations.

Purpose of the Study:

• To introduce Lipid14, an updated AMBER lipid force field.
• To enable tensionless molecular dynamics simulations of diverse lipid types.
• To ensure compatibility with existing AMBER force fields for biomolecules.

Main Methods:

• Revision and updating of Lennard-Jones and torsion parameters for lipid head and tail groups.
• Calculation of updated partial charges for lipid molecules.
• Performing 0.5 μs tensionless molecular dynamics simulations for six distinct lipid types.

Main Results:

• Successful simulation of lipid bilayers without applied surface tension.
• Favorable agreement between simulated and experimental data for area per lipid, volume per lipid, and bilayer thickness.
• Accurate prediction of NMR order parameters, scattering data, and lipid lateral diffusion coefficients.

Conclusions:

• Lipid14 provides a robust and validated force field for simulating various lipid bilayers using the AMBER MD package.
• The modular design facilitates the inclusion of new lipid species.
• Compatibility with other AMBER force fields simplifies integrated biomolecular simulations.