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BP: Fachverband Biologische Physik

BP 25: Posters: Cytoskeleton

BP 25.9: Poster

Mittwoch, 13. März 2013, 17:30–19:30, Poster C

Measurement of F-actin localization tubes and their orientation distribution in three dimensions — •Evelin Jaschinski, Inka Kirchenbüchler, Ronald Springer, and Rudolf Merkel — Forschungszentrum Jülich GmbH, Wilhelm-Johnen-Straße, 52428 Jülich

Under appropriate conditions, the protein actin forms long and semiflexible filaments (F-actin). Due to their large persistence length (~17microns) fluorescently labeled filaments are ideally suited for light microscopic study of conformations and fluctuations. Experiments on labeled test filaments embedded in a non-labeled network enable quantification of the space available, i.e. the well-known localization tube. In recent work our group has analyzed distributions of curvature [1] and diameters of the tubes [2]. These results were analyzed assuming isotropic solutions. However, pronounced and long lasting anisotropy can be induced by sample shear. In order to characterize the impact of directional order of the filaments localization tubes we applied different shear history and measured in three dimension the orientation distributions at different protein concentrations. From them we calculated order parameters and compared the latter to nematic ordering.

[1] J.Glaser, D. Chakraborty, K. Kroy & I. Lauter, M. Degawa, N. Kirchgeßner, B. Hoffmann, R. Merkel, M. Giesen, Phys. Rev. Lett. 105, 037801 (2010)

[2] M. Romanowska, H. Hinsch, N. Kirchgeßner, M.Giesen, M. Degawa, B. Hoffmann, E. Frey, R. Merkel, EPL 86, 26003 (2009)