Modelling the effect of a GHz electric field on the dynamics of K⁺ ions in KcsA potassium channel

Abstract

The dynamics of potassium ions in a KcsA channel, located within a stochastically fluctuating medium, is modelled via the application of the molecular dynamics simulation method. We investigate the effect of presence and absence of an applied electric field, either constant or periodic, on the dynamics of the channel. It is found that the ions undergo a hopping motion when the channel is exposed to a constant electric field of strength 0.03 V/nm. Furthermore, an alternating electric field in the GHz range, normally present in the daily environment and encountered by most biological systems, is applied to the channel, showing that in this frequency range, the rigidity of the atomic bonds of the filter is increased, which in turn disturbs the ionic passage rate through the filter. Consequently, in this frequency range, the application of electric fields may affect the function of such channels.

Keywords::

• KcsA potassium channel
• electric field
• molecular dynamics
• ion hopping

Acknowledgements

H. Rafii-Tabar would like to thank Iran's National Elites Foundation (Bonyad Meli Nokhbegan) for a Research Chair in Computational Nanoneuroscience.