Berlin 2008 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 7: Posters I
BP 7.46: Poster
Montag, 25. Februar 2008, 17:00–19:30, Poster A
Effect of Cholesterol on the Collective Dynamics of Phospholipid Membranes — •Beate Brüning1,2, Tim Salditt2, and Maikel C. Rheinstädter3 — 1Institut Laue-Langevin, Grenoble, France — 2Institut für Röntgenphysik, Georg-August Universität Göttingen, Germany — 3Department of Physics and Astronomy, University of Missouri-Columbia, USA
Phospholipid membranes often serve as simple model systems to understand basic properties of their far more complex biological counterparts. Only recently, the collective short wavelength dynamics in a model membrane system (DMPC), i.e., the corresponding dispersion relation, were investigated by inelastic neutron scattering techniques [1]. The insertion of the membrane-active molecule cholesterol, which is known to regulate membrane fluidity, membrane permeability and the lateral mobility of proteins, is now a first step towards the understanding of coherent dynamics in physiologically relevant membrane systems. While the structure of phospholipid/cholesterol systems is well studied, their short scale dynamics are so far largely unknown. We have studied the influence of cholesterol to the collective short wavelength fluctuations of the phospholipid acyl chains using inelastic neutron scattering. The measurements were carried out with thermal as well as cold neutrons on the three-axis spectrometers IN12 and IN8 at the high flux reactor of the ILL in Grenoble, France. We were able to determine the dispersion relations within the plane of the membranes in the fluid and in the liquid ordered phase.
[1] M.C. Rheinstädter et al., Phys. Rev. Lett. 93, 108107 (2004).