Berlin 2018 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 20: Statistical Physics of Biological Systems DY (joint session DY/BP)

BP 20.9: Vortrag

Mittwoch, 14. März 2018, 12:15–12:30, BH-N 333

Nonequilibrium force-velocity relation for single polymerization motor — •Thomas Niedermayer^1,2 and Reinhard Lipowsky² — ¹Physikalisch-Technische Bundesanstalt (PTB), Berlin — ²Max-Planck-Institut für Kolloid- und Grenzflächenforschung, Potsdam

In biological cells, the force generating assembly of cytoskeletal filaments is a nonequilibrium process which is coupled to the hydrolysis of bound nucleotides. This complex phenomenon may be captured by a stochastic process involving the association, aging, and dissociation of subunits. Necessarily, aging increases the shrinkage velocity of filaments under load and decreases the stall force. A recently proposed recursive solution for the stochastic process enables us to calculate the force-velocity relation for single cytoskeletal filaments in agreement with extensive stochastic simulations. Both for actin filaments and microtubules, we predict the onset of fast depolymerization slightly above the stall force. This effect involves strong correlations of the subunit states, underlining the failure of mean field calculations.