Regensburg 2019 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 6: Poster I

BP 6.53: Poster

Montag, 1. April 2019, 17:30–19:30, Poster B2

Recovery behavior of stretched single vimentin filaments — •Julia Kraxner, Johanna Block, and Sarah Köster — Institut für Röntgenphysik, Georg-August-Universität Göttingen

Varying mechanical properties of different cell types are determined by the cytoskeleton. The cytoskeleton consists of microtubules and microfilaments, which are conserved throughout all metazoan cell types, and different types of intermediate filaments (IFs), expressed in a cell-type specific manner. Therefore, IFs are believed to have an important impact in determining the mechanical properties of different cell types. Using optical tweezers, combined with microfluidics and fluorescence microscopy, we directly probe the stress-strain behavior of single IFs. Regarding the force-strain curves, stretching a single filament shows three regimes: the elastic stretching of α-helices, a plateau region and a stiffening at high forces. One interpretation of this behavior is that within this plateau regime the α-helices in the rod-domain of the vimentin monomers uncoil to β-sheet like structures. This process is called α-β-transition and it is suggested to be reversible even though the energy barrier between these two states is quite high. Here, we investigate the filament recovery after this α-β-transition of untreated and chemically fixed vimentin filaments.