Nanosecond lipid dynamics in membranes containing cholesterol

Clare L. Armstrong, Wolfgang Häußler, Tilo Seydel, John Katsaras, Maikel C. Rheinstädter

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

Lipid dynamics in the cholesterol-rich (40 mol%) liquid-ordered (l o) phase of dimyristoylphosphatidylcholine membranes were studied using neutron spin-echo and neutron backscattering. Recent theoretical and experimental evidence supports the notion of the liquid-ordered phase in phospholipid membranes as a locally structured liquid, with small ordered 'domains' of a highly dynamic nature in equilibrium with a disordered matrix [S. Meinhardt, R. L. C. Vink and F. Schmid, Proc. Natl. Acad. Sci. U. S. A., 2013, 110(12), 4476-4481, C. L. Armstrong et al., PLoS One, 2013, 8(6), e66162]. This local structure was found to have a pronounced impact on the membranes' dynamical properties. We found that the long-wavelength dynamics in the liquid-ordered phase, associated with the elastic properties of the membranes, were faster by two orders of magnitude as compared to the liquid disordered phase. At the same time, collective nanoscale diffusion was significantly slower. The presence of a soft-mode (a slowing down) in the long-wavelength dispersion relationship suggests an upper size limit for the ordered lipid domain of ≈220 Å. Moreover, from the relaxation rate of the collective lipid diffusion of lipid-lipid distances, the lifetime of these domains was estimated to be about 100 nanoseconds.

Original languageEnglish
Pages (from-to)2600-2611
Number of pages12
JournalSoft Matter
Volume10
Issue number15
DOIs
StatePublished - Apr 21 2014

Funding

Fingerprint

Dive into the research topics of 'Nanosecond lipid dynamics in membranes containing cholesterol'. Together they form a unique fingerprint.

Cite this