Lipid Dynamics and Domain Formation in Model Membranes Composed of Ternary Mixtures of Unsaturated and Saturated Phosphatidylcholines and Cholesterol

Publikation: Beitrag in FachzeitschriftForschungsartikelBeigetragenBegutachtung

Beitragende

  • Dag Scherfeld - (Autor:in)
  • Nicoletta Kahya - , Technische Universität Dresden (Autor:in)
  • Petra Schwille - , Professur für Biophysik (Autor:in)

Abstract

In recent years, the implication of sphingomyelin in lipid raft formation has intensified the long sustained interest in this membrane lipid. Accumulating evidences show that cholesterol preferentially interacts with sphingomyelin, conferring specific physicochemical properties to the bilayer membrane. The molecular packing created by cholesterol and sphingomyelin, which presumably is one of the driving forces for lipid raft formation, is known in general to differ from that of cholesterol and phosphatidylcholine membranes. However, in many studies, saturated phosphatidylcholines are still considered as a model for sphingolipids. Here, we investigate the effect of cholesterol on mixtures of dioleoyl-phosphatidylcholine (DOPC) and dipalmitoyl-phosphatidylcholine (DPPC) or distearoyl-phosphatidylcholine (DSPC) and compare it to that on mixtures of DOPC and sphingomyelin analyzed in previous studies. Giant unilamellar vesicles prepared from ternary mixtures of various lipid compositions were imaged by confocal fluorescence microscopy and, within a certain range of sterol content, domain formation was observed. The assignment of distinct lipid phases and the molecular mobility in the membrane bilayer was investigated by fluorescence correlation spectroscopy. Cholesterol was shown to affect lipid dynamics in a similar way for DPPC and DSPC when the two phospholipids were combined with cholesterol in binary mixtures. However, the corresponding ternary mixtures exhibited different spatial lipid organization and dynamics. Finally, evidences of a weaker interaction of cholesterol with saturated phosphatidylcholines than with sphingomyelin (with matched chain length) are discussed.

Details

OriginalspracheEnglisch
Seiten (von - bis)3758-3768
Seitenumfang11
FachzeitschriftBiophysical journal
Jahrgang85
Ausgabenummer6
PublikationsstatusVeröffentlicht - Dez. 2003
Peer-Review-StatusJa

Externe IDs

PubMed 14645066

Schlagworte

ASJC Scopus Sachgebiete