Helical Inclusions in Phospholipid Membranes: Lipid Adaptation and Chiral Order

J Phys Chem Lett. 2019 Sep 19;10(18):5629-5633. doi: 10.1021/acs.jpclett.9b02252. Epub 2019 Sep 9.

Abstract

The lipid bilayer is a flexible matrix that is able to adapt in response to the perturbation induced by inclusions, such as peptides and proteins. Here we use molecular dynamics simulations with a coarse-grained model to investigate the effect of a helical inclusion on a lipid bilayer in the liquid disordered phase. We show that the helical inclusion induces a collective tilt of acyl chains, with a small, yet unambiguous difference between a right- and a left-handed inclusion. This behavior is rationalized using the elastic continuum theory: The magnitude of the chiral (twist) deformation of the bilayer is determined by the interaction at the lipid/inclusion interface, and the decay length is controlled by the elastic properties of the bilayer. The lipid reorganization can thus be identified as a generic mechanism that, together with specific interactions, contributes to chiral recognition in phospholipid bilayers. An enhanced response is expected in highly ordered environments, such as rafts in biomembranes, with a potential impact on membrane-mediated interactions between inclusions.

MeSH terms

  • Elasticity
  • Hydrophobic and Hydrophilic Interactions
  • Kinetics
  • Lipid Bilayers / chemistry*
  • Molecular Conformation
  • Molecular Dynamics Simulation*
  • Phase Transition
  • Phospholipids / chemistry*
  • Surface Properties
  • Temperature
  • Thermodynamics

Substances

  • Lipid Bilayers
  • Phospholipids