Dispersion relation of lipid membrane shape fluctuations by neutron spin-echo spectrometry

We have studied the mesoscopic shape fluctuations in aligned multilamellar stacks of 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine bilayers using the neutron spin-echo technique. The corresponding in plane dispersion relation tau-1(q//) at different temperatures in the gel (ripple, Pbeta') an...

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Bibliographic Details
Published inPhysical review letters Vol. 97; no. 4; p. 048103
Main Authors Rheinstädter, Maikel C, Häussler, Wolfgang, Salditt, Tim
Format Journal Article
LanguageEnglish
Published United States 28.07.2006
Subjects
Computer Simulation
Dimyristoylphosphatidylcholine - chemistry
Membrane Fluidity
Membrane Lipids - chemistry
Models, Chemical
Models, Molecular
Molecular Conformation
Neutron Diffraction
Spectrum Analysis
Temperature
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Summary:We have studied the mesoscopic shape fluctuations in aligned multilamellar stacks of 1,2-dimyristoyl-sn-glycero-3-phoshatidylcholine bilayers using the neutron spin-echo technique. The corresponding in plane dispersion relation tau-1(q//) at different temperatures in the gel (ripple, Pbeta') and the fluid (Lalpha) phase of this model system has been determined. Two relaxation processes, one at about 10 ns and a second, slower process at about 100 ns can be quantified. The dispersion relation in the fluid phase is fitted to a smectic hydrodynamic theory, with a correction for finite qz resolution. We extract values for the bilayer bending rigidity kappa, the compressional modulus of the stacks B, and the effective sliding viscosity eta3. The softening of a mode which can be associated with the formation of the ripple structure is observed close to the main phase transition.
ISSN:0031-9007
1079-7114
DOI:10.1103/physrevlett.97.048103