Regensburg 2013 – scientific programme

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BP: Fachverband Biologische Physik

BP 13: Imaging

BP 13.9: Talk

Tuesday, March 12, 2013, 11:45–12:00, H44

Quantifying Lipid and Protein Diffusion in Black Lipid Membranes — •Kerstin Weiß and Jörg Enderlein — Drittes Physikalisches Institut, Georg-August-Universität Göttingen, Göttingen, Germany

Lipid diffusion is crucial in many biological processes. However, accurately determining diffusion coefficients in membranes remains difficult. We used dual-focus fluorescence correlation spectroscopy (2f-FCS) to measure lipid diffusion in black lipid membranes (BLMs), i.e. lipid bilayers spanned over a pore. To generate these bilayers a commercially available setup is employed. We first tested the effect of different ionic strengths in neutral and negatively charged bilayers. Moreover, we investigated the influence of mono- vs. divalent ions. While monovalent ions have no effect on lipid diffusion in both systems, addition of divalent ions severely decreased the lipid*s diffusion coefficient in negatively charged BLMs. Furthermore, the investigated the validity of the Saffman-Delbrück model which is used to describe protein diffusion in lipid membranes.