Cationic dimyristoylphosphatidylcholine and dioleoyloxytrimethylammonium propane lipid bilayers: Atomistic insight for structure and dynamics

Tutkimustuotos: Lehtiartikkelivertaisarvioitu

Tutkijat

  • Wei Zhao
  • Andrey A. Gurtovenko
  • Ilpo Vattulainen
  • Mikko Karttunen

Organisaatiot

  • University of Calgary
  • Russian Academy of Sciences
  • Tampere University of Technology
  • University of Waterloo

Kuvaus

We performed atomistic molecular dynamics simulations of lipid bilayers consisting of a mixture of cationic dioleoyloxytrimethylammonium propane (DOTAP) and zwitterionic dimyristoylphosphatidylcholine (DMPC) lipids at different DOTAP fractions. Our primary focus was the specific effects of unsaturated lipid chains on structural and dynamic properties of mixed cationic bilayers. The bilayer area, as well as the ordering of lipid tails, shows a pronounced nonmonotonic behavior when TAP lipid fraction increases. The minimum in area (maximum in ordering) was observed for a bilayer with TAP fraction of 0.4, that is, at lower TAP fractions compared with saturated PC/TAP bilayers. Adding unsaturated DOTAP lipids into DMPC bilayers was found to promote lipid chain interdigitation and to fluidize lipid bilayers, as seen through enhanced lateral lipid diffusion. The speed-up in lateral diffusion at large DOTAP fractions results from increasing area per lipid, whereas at smaller DOTAP concentrations, the competing effect due to lipid-lipid complex formation results in a constant value for diffusion. We also characterize the lipid headgroup orientation and the interactions between DMPC and DOTAP lipids, which were found to form PC-PC and PC-TAP pairs, and the formation of lipid clusters.

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut269-276
Sivumäärä8
JulkaisuJournal of Physical Chemistry B
Vuosikerta116
Numero1
TilaJulkaistu - 12 tammikuuta 2012
OKM-julkaisutyyppiA1 Julkaistu artikkeli, soviteltu

ID: 15879356