Lipid lateral diffusion in bilayers with phosphatidylcholine, sphingomyelin and cholesterol: An NMR study of dynamics and lateral phase separation
2006 (English)In: Chemistry and Physics of Lipids, Vol. 141, 179-84 p.Article in journal (Refereed) Published
Pulsed field gradient (pfg)-NMR measurements of the lipid lateral diffusion coefficients in several macroscopically aligned bilayer systems were summarized from previous and new studies. The aim was to carry out a comparison of the translational dynamics for bilayers with various mixtures of l,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), l,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and chicken egg yolk sphingomyelin (eSM), with or without cholesterol. New useful information was obtained on the dynamics in these lipid bilayers that has not been previously appreciated. Thus, we were able to propose that the driving force behind the phase separation into ld and lo phases evolves from the increasing difficulty to incorpotate DOPC into a highly ordered phase. Our results suggest that DOPC has a preference to be located in a disordered phase, while DPPC and eSM prefer the ordered phase. Quite unexpectedly, CHOL seems to partition into both phases to roughly the same extent, indicating that CHOL has no particular preference for any of the ld or lo phases, and there are no specific interactions between CHOL and saturated lipids.
Place, publisher, year, edition, pages
2006. Vol. 141, 179-84 p.
Pulsed field gradient NMR; Fluid ordered phase; Fluid disordered phase; Lipid rafts; Phase behaviour
IdentifiersURN: urn:nbn:se:umu:diva-12421DOI: doi:10.1016/j.chemphyslip.2006.02.011OAI: oai:DiVA.org:umu-12421DiVA: diva2:152092