Coarse-grained molecular dynamics simulation of binary charged lipid membranes: Phase separation and morphological
Hiroaki Ito1, Yuji Higuchi2, Naofumi Shimokawa3
1Department of Mechanical Engineering, Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan.
Physical Review. E
|November 15, 2016
Summary
Charged lipid bilayers exhibit unique phase separation and pore formation dynamics. Electrostatic repulsion influences vesicle morphology, leading to disk, string, and bicelle structures via molecular-level mechanisms.
Area of Science:
- Biophysics
- Materials Science
- Computational Chemistry
Background:
- Biomembranes are essential structures composed of neutral and charged lipids.
- Lipid bilayers display diverse functional structures and dynamics crucial for biological processes.
Purpose of the Study:
- Investigate phase separation and morphological dynamics in charged lipid bilayer vesicles.
- Elucidate the role of electrostatic repulsion in altering lipid bilayer behavior.
Main Methods:
- Employed coarse-grained molecular dynamics (MD) simulations.
- Analyzed phase separation and morphological transformations in charged vesicles.
Main Results:
- Electrostatic repulsion between charged head groups delays or inhibits lateral phase separation.
- Observed morphological changes including pore formation, disk, string, and bicelle structures.
- Identified a molecular-level mechanism for pore formation initiated by local molecular orientation disturbance.
Conclusions:
- Charged lipids significantly alter phase separation mechanisms compared to neutral lipids.
- Electrostatic repulsion drives complex morphological transformations in lipid vesicles.
- The study provides a detailed molecular mechanism for pore formation in charged lipid domains.
