Dipolar ordering in the ripple phases of molecular-scale models of lipid membranes

J Phys Chem B. 2008 Feb 21;112(7):1968-75. doi: 10.1021/jp0762020. Epub 2008 Jan 29.

Abstract

Symmetric and asymmetric ripple phases have been observed to form in molecular dynamics simulations of a simple molecular-scale lipid model. The lipid model consists of an dipolar head group and an ellipsoidal tail. Within the limits of this model, an explanation for generalized membrane curvature is a simple mismatch in the size of the heads with the width of the molecular bodies. The persistence of a bilayer structure requires strong attractive forces between the head groups. One feature of this model is that an energetically favorable orientational ordering of the dipoles can be achieved by out-of-plane membrane corrugation. The corrugation of the surface stabilizes the long range orientational ordering for the dipoles in the head groups which then adopt a bulk anti-ferroelectric state. We observe a common feature of the corrugated dipolar membranes: the wave vectors for the surface ripples are always found to be perpendicular to the dipole director axis.

MeSH terms

  • Computer Simulation
  • Lipid Bilayers*
  • Models, Biological*
  • Models, Molecular
  • Molecular Conformation
  • Motion*
  • Static Electricity

Substances

  • Lipid Bilayers