Pressure-induced Interdigitation in Phospholipid Bilayer Membranes

Abstract

Pressure studies on the bilayer phase transitions of ester-linked diacylphosphatidylcholines (diacyl-PCs) and ether-linked dialkyl-PCs are reviewed. Comparing the bilayer phase diagrams and the thermodynamic quantities of phase transitions for diacyl-PCs with those for dialkyl-PCs, the difference in lateral interaction between polar head groups of diacyl-PC and dialkyl-PC was elucidated. The mechanism of bilayer interdigitation induced by high-pressure, which is characteristic of phospholipids with a choline head group, is discussed on the basis of molecular interaction in lipid bilayer membranes.