Berlin 2015 – scientific programme

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BP: Fachverband Biologische Physik

BP 23: Posters: Molecular Motors

BP 23.1: Poster

Tuesday, March 17, 2015, 14:00–16:00, Poster A

Kinesin motors pulling subdiffusive cargos in cytosol: from normal to anomalous transport and motor cyclic kinetics — •Igor Goychuk — Institute for Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam-Golm, Germany

We study [1] transport of subdiffusing particles by kinesin motors within a generalized flashing potential ratchet model. Here, the binding potential flashes are bidirectionally coupled to a two-state biochemical cyclic kinetics of the motor driven by ATP hydrolysis. The motor catches and pulls on a tether cargo which freely subdiffuses otherwise. Subdiffusion of cargo is modeled within a Generalized Langevin Equation approach featured by a power-law scaling memory kernel with a finite memory cutoff reflecting finite macroscopic viscosity of viscoelastic cytosol [2]. This theory extends our previous modeling [3] which explains how one and the same motors can realize both normal and anomalous transport of submicron cargos in the same cell, depending, in particular, on the cargo size and the motor turnover frequency. We not only confirm our previous major findings, but also explain how anomalously slow enzyme turnover naturally emerges within our description, which is based on the fundamentals of statistical mechanics [2]. Thermodynamic efficiency of the motor can be very high (> 50 %) even within this strongly anomalous transport regime.
[1] I. Goychuk, arXiv:1410.2416 [physics.bio-ph] (2014).
[2] I. Goychuk, Adv. Chem. Phys. 150, 187 (2012).
[3] I. Goychuk, V. Kharchenko, R. Metzler, PLoS ONE 9, e91700 (2014); Phys. Chem. Chem. Phys. 16, 16524 (2014).