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BP: Fachverband Biologische Physik

BP 23: Cytoskeleton (joint BP/CPP)

BP 23.6: Vortrag

Mittwoch, 2. April 2014, 11:00–11:15, HÜL 386

Elasto-plastic response of reversibly crosslinked biopolymer bundles — •Poulomi Sadhukhan and Claus Heussinger — Institute for theoretical Physics, University of Goettingen, Friedrich Hund Platz 1, 37077 Goettingen, Germany.

We model cytoskeletal actin bundles under stress in order to explain the elasto-plastic response observed in recent experiments (D. Strehle et al 2011). In doing so, we allow crosslinks to reversibly un- and rebind to the actin filaments. Cross-link reorganization leads to defect formation, which we speculate to be the underlying mechanism responsible for the residual ("plastic") deformation observed in the experiments. The problem is studied for two cases related by the Legendre transformation - under given force and under given deflection of the bundle. Our main result is in agreement with the experiment. We show that a small bending stress can deform the bundle for soft crosslinks, and shows plastic-like behaviour. On the other hand, bundles with stiff crosslinks show elastic behaviour. Along with this, we also observe how the defect position is related to the applied stress and crosslink stiffness and how the required stress to create a residual deformation of the bundle varies with the crosslink stiffness.