Localization of Cholesterol within Supported Lipid Bilayers Made of a Natural Extract of Tailor-Deuterated Phosphatidylcholine

Research output: Contribution to journalArticle

Abstract

Cholesterol is an essential component of mammalian membranes and is known to induce a series of physicochemical changes in the lipid bilayer. Such changes include the formation of liquid-ordered phases with an increased thickness and a configurational order as compared to liquid-disordered phases. For saturated lipid membranes, cholesterol molecules localize close to the lipid head group-tail interface. However, the presence of polyunsaturated lipids was recently shown to promote relocation of cholesterol toward the inner interface between the two bilayer leaflets. Here, neutron reflection is used to study the location of cholesterol (both non-deuterated and per-deuterated versions are used) within supported lipid bilayers composed of a natural mixture of phosphatidylcholine (PC). The lipids were produced in a genetically modified strain of Escherichia coli and grown under specific deuterated conditions to give an overall neutron scattering length density (which depends on the level of deuteration) of the lipids matching that of D2O. The combination of solvent contrast variation method with specific deuteration shows that cholesterol is located closer to the lipid head group-tail interface in this natural PC extract rather than in the center of the core of the bilayer as seen for very thin or polyunsaturated membranes.

Details

Authors
  • Sarah Waldie
  • Tania K Lind
  • Kathryn Browning
  • Martine Moulin
  • Michael Haertlein
  • V Trevor Forsyth
  • Alessandra Luchini
  • Gernot A Strohmeier
  • Harald Pichler
  • Selma Maric
  • Marité Cárdenas
External organisations
  • Malmö University
  • Uppsala University
  • Institut Laue Langevin
  • Keele University
  • Graz University of Technology
Original languageEnglish
Pages (from-to)472-479
Number of pages8
JournalLangmuir
Volume34
Issue number1
Publication statusPublished - 2018 Jan 9
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes