Cholesterol shows preference for the interior of polyunsaturated lipid membranes

J Am Chem Soc. 2008 Jan 9;130(1):10-1. doi: 10.1021/ja076641c. Epub 2007 Dec 13.

Abstract

Recent neutron scattering experiments showed a striking manifestation of the aversion between polyunsaturated fatty acid (PUFA)-containing lipids and cholesterol. Selectively deuterated cholesterol/ 1,2-diarachidonylphosphatidylcholine (DAPC) samples revealed that the hydroxyl of the sterol resides at the center of the bilayer. Here we use a recently parametrized coarse grain simulation model to shed light on these puzzling experimental observations. Using a simulation setup in close correspondence to the experimental conditions, we reproduce the experimental neutron scattering profiles to a large extent. The simulations allow us to analyze the behavior of cholesterol in detail; we show that the interaction of cholesterol with the PUFA chains of DAPC leads to a fast flip-flop rate for the sterol and an increased preference of the sterol for the unusual location embedded between the monolayer leaflets.

MeSH terms

  • Binding Sites
  • Cholesterol / chemistry
  • Cholesterol / metabolism*
  • Fatty Acids, Unsaturated / chemistry
  • Fatty Acids, Unsaturated / metabolism*
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism*
  • Neutron Diffraction
  • Phosphatidylcholines

Substances

  • Fatty Acids, Unsaturated
  • Lipid Bilayers
  • Phosphatidylcholines
  • 1,2-diarachidonoyl-glycero-3-phosphocholine
  • Cholesterol