Intra- and intermolecular interactions of phospholipid headgroups within a two-dimensional hexagonal lattice

Abstract Using different types of atom-atom potential functions the energetically most stable conformations of glycero-phosphatidylethanolamine (GPE) in a two-dimensional hexagonal lattice were calculated. The results show that the conformational behaviour of the phospholipid headgroups is determined mainly by the intramolecular electrostatic repulsion between the phosphate group ester oxygen lone pairs. The best agreement with X-ray torsion angles was obtained reducing the CNDO-APSG net atomic charges by a factor of 3 − 1 2 . The energetically preferred regions of headgroup torsion angles give a molecular model of the headgroup reorientational processes in agreement with NMR results.