Surface Occupancy Plays a Major Role in Cholesterol's Condensing Effect

Krause M. R., Turkyilmaz S., Regen S. L.

LANGMUIR, vol.29, no.33, pp.10303-10306, 2013 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 29 Issue: 33
  • Publication Date: 2013
  • Doi Number: 10.1021/la402263w
  • Journal Name: LANGMUIR
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.10303-10306
  • Middle East Technical University Affiliated: No


The condensing power of cholesterol and 5 alpha-cholestane has been examined in liposomal membranes made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Quantitative nearest-neighbor recognition (NNR) analysis and fluorescence measurements using phase-sensitive probe Laurdan have demonstrated that 5 alpha-cholestane exhibits a substantially weaker condensing effect. This fact, in and of itself, provides compelling evidence that cholesterol's condensing effect is critically dependent on having its steroid nucleus at the membrane surface.