Dissipative particle dynamics simulation study of the bilayer-vesicle transition

• 来源期刊: 中国科学B辑（英文版）
• 年，卷（期）: 2008,（8）
• 页码范围: 743-750
• 页数: 8页
• 语种: 英文
• DOI: 10.1007/s 11426-008-0077-5

摘要

A bilayer structure is an important immediate for the vesicle formation. However, the mechanism for the bilayer-vesicle transition remains unclear. In this work, a dissipative particle dynamics (DPD) simula-tion method was employed to study the mechanism of the bilayer-vesicle transition. A coarse-grained model was built based on a lipid molecule termed dimyristoylphosphatidylcholine (DMPC). Simulations were performed from two different initial configurations: a random dispersed solution and a ten-sionless bilayer. It was found that the bilayer-vesicle transition was driven by the minimization of the water-tail hydrophobic interaction energy, and was accompanied with the increase of the position en-tropy due to the redistribution of water molecules. The bulk pressure was reduced during the bi-layer-vesicle transition, suggesting the evolved vesicle morphology was at the relatively low free en-ergy state. The membrane in the product vesicle was a two-dimensional fluid. It can be concluded that the membrane of a vesicle is not interdigitated and most of the bonds in lipid chains are inclined to orient along the radical axis of the vesicle.