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BP: Fachverband Biologische Physik

BP 29: Posters: Biopolymers \& Biomaterials

BP 29.4: Poster

Thursday, March 17, 2011, 17:15–20:00, P3

Temperature-dependent Properties of Keratin 8/18 — •Ines Martin¹, Anke Leitner¹, Stephanie Portet², Michael Beil³, Harald Herrmann⁴, and Othmar Marti¹ — ¹Department of Experimental Physics, Ulm University, Ulm, Germany — ²Department of Mathematics, University of Manitoba, Winnipeg, Canada — ³Department of Internal Medicine I, Ulm University, Ulm, Germany — ⁴Division of Molecular Genetics, German Cancer Research Center, Heidelberg, Germany

The cytoskeleton of epithelial cells consists of three types of filaments: microtubules, intermediate filaments and actin filaments. In our work, we have a closer look at intermediate filaments, which are responsible for the stiffness of cells and responses to mechanical stimuli.

The Keratin 8/18 dimer is a basic module of intermediate filaments. Its assembly process is a three step process which is highly sensitive to temperature changes and has very interesting kinetics. Therefore we assembled it in vitro at different temperatures (4°C, 21°C, 30°C, 37°C) and for different durations (10s, 1min, 10min, 20min). The resulting filaments were diluted to a suitable concentration for detection of single filaments and imaged with the help of Transmission Electron Microscopy. The samples were negatively stained with Uranylacetate to enhance the contrast.

With these pictures, the length and diameter of filaments of the different samples were measured and compared by fitting to existing models.