Dresden 2011 – scientific programme
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BP: Fachverband Biologische Physik
BP 3: Biopolymers and Biomaterials I (with CPP)
BP 3.8: Talk
Monday, March 14, 2011, 12:30–12:45, ZEU 222
Stiffening effect of cholesterol on large unilamellar vesicles based on POPC — •Thomas Hellweg1, Laura Rodriguez-Arriaga Rodriguez-Arriaga2, Ivan Lopez-Montero2, Bela Farago3, and Francisco Monroy2 — 1Universität Bielefeld, PC III, Universitätsstr. 25 33615 Bielefeld, Germany — 2Universidad Complutense, 28040 Madrid, Spain — 3ILL, 6 rue Jules Horowitz, BP 156, F-38042 Grenoble Cedex 9, France
In the present contribution the center of mass diffusion and shape fluctuations of unilamellar POPC vesicles are studied by means of neutron spin-echo (NSE) in combination with dynamic light scattering (DLS). The intermediate scattering functions were measured for several different values of the momentum transfer q and for different cholesterol contents in the membrane. The combined analysis of NSE and DLS data allows the calculation of the bending elastic constant κ of the bilayer. A stiffening effect monitored as an increase of κ with increasing cholesterol molar ratio is evidenced from these measurements [1]. At high values of q apparently intermonolayer friction modes can be resolved using NSE [2].
The presented approach could also be applied to study the influence of membrane proteins on κ or of substances like e.g. Gramicidine.
Rodriguez Arriaga, L., I. Lopez-Montero, F. Monroy, G. Orts Gil, B. Farago und T. Hellweg: Biophys. J., 96, 3629–3637, 2009.
Arriaga, L. R., R. Rodriguez-Garcia, I. Lopez-Montero, B. Farago, Th. Hellweg, und F. Monroy: Euro. Phys. J. E, 31, 105–113, 2010.