Berlin 2005 – wissenschaftliches Programm
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DY: Dynamik und Statistische Physik
DY 43: Einstein Symposium Brownian Motion, Diffusion and Beyond (SYBM) – Contributed Talks I
DY 43.13: Vortrag
Dienstag, 8. März 2005, 17:30–17:45, TU H2032
Studying Diffusion in Monolayers at the Air/Water Interface by Single-Particle-Tracking — •Carsten Selle1, Florian Rückerl1, Martin B. Forstner2, Douglas S Martin3, and Josef A. Käs1 — 1Universität Leipzig, Inst. Exp. Physik I, PWM, Linnestr. 5, 04103 Leipzig — 2UC Berkeley — 3Brandeis University
The diffusion properties of single biological membrane components were investigated by a Single-Particle-Tracking (SPT) technique employing monolayers at the air/water interface combined with Monte Carlo simulations. Studies of lipid diffusion with long observation times revealed that (camera) noise can lead to the assumption of subdiffusion. Protein diffusion was mimicked by the motion of surface charged fluorescent polystyrene latexes in inhomogeneous monolayers. Associated with liquid-condensed (LC) lipid domains, dimensionally reduced diffusion was found. We assume that dipole-dipole interactions of beads with LC domains give rise to an underlying attractive potential. This view point is supported by Monte-Carlo simulations. Furthermore, the simulations demonstrated that model protein diffusion might be affected by the domain size and the potential depth. It is conceivable that living cells could make use of a similar mechanism to enhance kinetics of bimolecular enzyme reactions in the membrane.