Hexagonal arrangement of phospholipids in bilayer membranes*

Abstract

The phospholipid membrane plays a key role in myriad biological processes and phenomena, and the arrangement structure of membrane determines its function. However, the molecular arrangement structure of phospholipids in cell membranes is difficult to detect experimentally. On the basis of molecular dynamic simulations both in a non-destructive way and at native environment, we observed and confirmed that the phospholipids self-assemble to a hexagonal arrangement structure under physiological conditions. The underlying mechanism was revealed to be that there are hexagonal arrangement regions with a lower free energy around each lipid molecule. The findings potentially advance the understanding of biological functions of phospholipid bilayers.