Seminar “Biopolymers, their networks and implications for mechanobiology”

Date

Monday, 20th of May of 2019

Time

10:00 am

Place

University of Barcelona
Faculty of Physics Building
Room 3.25, 3rd floor 

Speaker

Dr Fred MacKintosh, Rice University (USA)

Abstract

The mechanics of cells and tissues are largely governed by scaffolds of filamentous proteins or biopolymers that make up the cytoskeleton, as well as extracellular matrices.

We will review the basic biophysics of networks of filamentous proteins, focusing on the two relevant limits of (1) semiflexible polymers and (2) stiff fibers. Both limits result in nonlinear elastic networks, but such nonlinearity can arise either from single-chain or collective effects. Unlike most synthetic polymers, the actin cytoskeleton exhibits a non-equilibrium steady state distribution of polymer length, which is maintained by various polymerization and depolymerization mechanisms.

We discuss how such turnover can affect stress relaxation in the cytoskeleton. We will also present recent theoretical predictions and experimental evidence for mechanical phase transitions in extracellular networks.19