Regensburg 2004 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 50: Poster Session "Biological Physics"
AKB 50.56: Poster
Freitag, 12. März 2004, 10:30–13:00, B
Diffusion in Inhomogeneous Monolayers as Biomimetic Membranes — •Carsten Selle1, Florian Rückerl1, Douglas S. Martin2, Martin B. Forstner2, Natalie Bordag1, Marlis Wilke1, and Josef Käs1,2 — 1Fakultaet fuer Physik und Geowissenschaften, Universitaet Leipzig — 2University of Texas at Austin
Lateral diffusion within membranes plays an important role for essential cellular processes as, e.g., membrane formation and inter- / intracellular signalling. We model the diffusion of a protein represented by a charged polystyrene latex within a lipid monolayer at the air-water interface mimicking a cell membrane with spatial inhomogeneities - e.g. lipid rafts - on an expanded scale. For this purpose, the motion of carboxylated polystyrene latexes diffusing in simple lipid monolayers (pure a) dimyristoyl phosphatidylethanolamine, DMPE and b) methyl palmitate) on aqueous subphases has been tracked. We observed that the diffusion of the particles is apparently influenced by the presence of liquid condensed domains. Presumably, dipolar interactions between the domains and the charged particles induce this behavior. This motion was qualitatively modeled by Monte Carlo simulations.
Furthermore, we study the effect of the antimicrobial peptide Gramicidin S on the phase behavior and the diffusion properties of the model systems mentioned above.