Premium
Simulation of the effect of an external GHz electric field on the potential energy profile of Ca 2+ ions in the selectivity filter of the Ca V Ab channel
Author(s) -
Adiban Jamal,
Jamali Yousef,
RafiiTabar Hashem
Publication year - 2018
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.25456
Subject(s) - electric field , ion , chemistry , ion transporter , ion channel , potential of mean force , umbrella sampling , analytical chemistry (journal) , molecular dynamics , selectivity , membrane , membrane potential , atomic physics , chemical physics , computational chemistry , physics , biochemistry , receptor , organic chemistry , chromatography , quantum mechanics , catalysis
Ca V channels are transmembrane proteins that mediate and regulate ion fluxes across cell membranes, and they are activated in response to action potentials to allow Ca 2+ influx. Since ion channels are composed of charge or polar groups, an external alternating electric field may affect the ion‐selective membrane transport and the performance of the channel. In this article, we have investigated the effect of an external GHz electric field on the dynamics of calcium ions in the selectivity filter of the Ca V Ab channel. Molecular dynamics (MD) simulations and the potential of mean force (PMF) calculations were carried out, via the umbrella sampling method, to determine the free energy profile of Ca 2+ ions in the Ca V Ab channels in presence and absence of an external field. Exposing Ca V Ab channel to 1, 2, 3, 4, and 5 GHz electric fields increases the depth of the potential energy well and this may result in an increase in the affinity and strength of Ca 2+ ions to binding sites in the selectivity filter the channel. This increase of strength of Ca 2+ ions binding in the selectivity filter may interrupt the mechanism of Ca 2+ ion conduction, and leads to a reduction of Ca 2+ ion permeation through the Ca V Ab channel.