Berlin 2012 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 16: Molecular Motors

BP 16.2: Hauptvortrag

Mittwoch, 28. März 2012, 15:30–16:00, H 1028

Collective properties of molecular motors — •Jean-François Joanny — Institut Curie centre de recherche 26 rue d'Ulm 75248 Paris cedex 05

In many instances, in cells molecular motors such as myosins act in groups and show spectacular collective properties such as dynamic phase transitions, oscillations or bidirectional motion. We propose a "soft motor model" where the tail of the motors has a finite stiffness and is rigidly connected to the moving motor filament. The head of the motors is described by a classical two level system. The important parameter which governs the behavior of the motors is the pinning parameter which compares the maximum stiffness of the interaction potential to the stiffness of the motors.

At high enough activities, motor clusters can have two spontaneous velocities in opposite directions. If the number of motors in the cluster is not infinite, the motion reverses between the states corresponding to the two velocities over a finite reversal time. When the motors are rigidly bound to the motor filament, we calculate the reversal time as a first passage time between two non equilibrium states and show that it increases exponentially with the number of motors as found in simulations of Badoual et al.

Finally we discuss the case of molecular motors coupled via hydrodynamic interactions.