Regensburg 2013 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 49: Colloids and Complex Liquids III
CPP 49.8: Vortrag
Freitag, 15. März 2013, 11:30–11:45, H40
Bilayer undulation dynamics in unilamellar phospholipid vesicles: Influence of temperature, cholesterol and trehalose — •Beate-Annette Brüning1, Sylvain Prévost1,2, Ralf Stehle1, Roland Steitz1, Peter Falus3, Bela Farago3, and Thomas Hellweg4 — 1Helmholtz Zentrum Berlin, Hahn-Meitner Platz 1, 14109 Berlin, Germany — 2Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany — 3Institut Laue-Langevin, B. P. 156, 38042 Grenoble Cedex 9, France — 4Universität Bielefeld, Universitätsstraße 25, 33615 Bielefeld, Germany
We report a combined dynamic light scattering (DLS) and neutron spin-echo (NSE) study on lipid vesicles composed of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC), respectively under the influence of temperature and the membrane additives cholesterol and trehalose. We study bilayer undulation and bulk diffusion dynamics using neutron spin-echo spectroscopy, on two distinct time scales, namely around 25 ns and 100 ns. Finally, we calculate the respective bilayer bending rigidities κ for all types of lipid vesicles. We observe a bilayer softening around the main phase transition temperature Tm of the single lipid model system, and a bilayer stiffening the more cholesterol is added, whereas the insertion of trehalose hardly changes the bilayer undulations and membrane rigidity κ [1]. We explain our findings on the basis of a free volume available to lipid molecules in the membrane plane, which encounters the most pronounced changes in the acyl chain regime. [1] B. Brüning, S. Prévost, R. Stehle, R. Steitz, P. Falus, B. Farago, T. Hellweg, submitted.