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BP: Fachverband Biologische Physik
BP 54: Statistical Physics of Biological Systems I (Joint Session BP/DY)
BP 54.4: Talk
Thursday, March 23, 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).