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DY: Fachverband Dynamik und Statistische Physik

DY 50: Statistical Physics of Biological Systems I (Joint Session BP/DY)

DY 50.4: Vortrag

Donnerstag, 23. März 2017, 15:45–16:00, ZEU 250

Magnetosensing with ion channels and the origin of anomalous gating kinetics — •Igor Goychuk — Institute for Physics and Astronomy, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam-Golm, Germany

It was earlier proposed by J. Kirschvink et al. that magnetosensitive ion channels can be involved in sensing weak magnetic fields by various animals, with a magnetic nanoparticle coupled to a gate of an ion channel and serving as sensor. I consider a generalization of this hypothesis, where a magnetic nanorod made of several magnetosomes is elastically coupled to a cluster of ion channels [1]. Magnetic nanorod reorients in viscoelastic cytosol following a Generalized Langevin equation dynamics and a gating spring instability leads to bistable open-shut dynamics in such a hypothetical magnetosensory complex. Is the proposed mechanism feasible for realistic parameters? It is shown that YES, and interestingly enough the open-shut dynamics can exhibit both stretched-exponential and power law features in the residence time distributions. Beyond this particular context of magnetosensing, viscoelasticity of the medium in which the sensory part of ion channel moves is proposed as a generic mechanism to explain the origin of anomalous gating kinetics observed in several naturally occurring ion channels.
[1] I. Goychuk, Phys. Rev. E 92, 042711 (2015).