Regensburg 2010 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 5: Posters: Biopolymers and Biomaterials

BP 5.8: Poster

Montag, 22. März 2010, 17:15–20:00, Poster B1

Comparison of nanomechanical properties of in vivo and in vitro keratin networks — •Anke Leitner¹, Tobias Paust¹, Harald Herrmann², Michael Beil³, and Othmar Marti¹ — ¹Institute of Experimental Physics, Ulm University — ²Division of Molecular Genetics, German Cancer Research Center, Heidelberg — ³Department of Internal Medicine I, Ulm University

The mechanical properties of epithelial cells are mainly determined by the cytoskeleton. The cytoskeleton consists of three different protein networks, microtubules, the transport pathways of the cell, actin filaments, responsible for the movement, and intermediate filaments that provide the stiffness and response to mechanical stimuli. In order to find out more about the mechanical properties of the intermediate filament keratin cytoskeleton it is useful to have a look on in vitro assembled keratin filaments. In the work presented here we compare the mechanical properties of the extracted keratin cytoskeleton of pancreatic carcinoma cells with the mechanical properties of in vitro assembled keratin 8/18 networks. For this purpose we use microrheology measurements with embedded tracer beads. This method is a suitable tool, because the size of the beads compared to the meshsize of the network allows us to treat the network as a continuum. Observing the beads motion with a CCD-High-Speed-Camera then leads to the dynamic shear modulus. We draw conclusions on the network topology of the authentic isolated cellular networks and the recombinant in vitro assembled K8/18 filament systems based on the mechanical behaviour.