Split Membrane: A New Model to Accelerate All-Atom MD Simulation of Phospholipid Bilayers.

Area of Science:

• Computational Biophysics
• Molecular Modeling
• Membrane Biophysics

Background:

• All-atom molecular dynamics (MD) simulations are crucial for understanding cell membrane dynamics and protein-membrane interactions.
• Simulating lipid diffusion in cell membranes is computationally expensive due to slow phospholipid dynamics in all-atom models.

Purpose of the Study:

• To develop a novel all-atom model that significantly accelerates lipid diffusion for enhanced molecular dynamics simulations.
• To enable faster and more affordable equilibration of large membrane systems and accurate prediction of protein-membrane interactions.

Main Methods:

• A new all-atom model was developed by splitting phospholipid molecules into head and tail groups.
• External lateral potentials were employed to maintain bilayer structure and compensate for the lipid split.
• The model's performance was validated using various phospholipids (PSM, POPC, POPS, POPE, POPA, cholesterol) and diverse membrane proteins (peripheral and transmembrane).

Main Results:

• The split model demonstrated a >10-fold increase in lateral lipid diffusion compared to conventional all-atom models.
• The model accurately predicted protein interaction sites and preferred phospholipid types for both peripheral and transmembrane proteins.
• Simulations showed efficient equilibration of large membrane systems with complex lipid compositions.

Conclusions:

• The developed split phospholipid model offers a computationally efficient approach for simulating large membrane systems.
• This model facilitates the identification of lipid-protein binding sites and accelerates the study of membrane protein interactions.
• The enhanced diffusion rates make it a valuable tool for membrane biophysics research at reduced computational cost.