Title: Physiology of ionophore transport of potassium and sodium ions across cell membranes: valinomycin and 18-crown-6 ether

Authors: Clifford W. Fong

Addresses: Eigenenergy, Adelaide, South Australia

Abstract: The processes involved in transport of K+ and Na+ by the carrier ionophores valinomycin and 18-crown-6 ether across cell membranes have been elucidated using quantum mechanical modelling: 1. Formation of the {ionophore-M+} complex: desolvation (ΔGdesolv) of the central cavity of the ionophore, change in configurational energy TΔS, desolvation of the M(H2O)6-7+. 2. Desolvation of the {ionophore-M+} complex prior to entering the membrane environment. 3. Permeation through the lipophilic environment of the membrane, which is dependent on the lipophilicity (ΔGlipo), dipole moment μ, and molecular volume of the {ionophore-M+} complex. 4. Release of the M+ on the intracellular side, and diffusion of the free ionophore back towards the extracellular side to restart the process. Results from this study show that it is possible to design molecular structures to enhance the ability of crown ethers to selectively transport alkali metal ions across lipid membranes.

Keywords: ionophore; valinomycin; crown ether; potassium ions; sodium ions; cell membrane transport; modelling; physiology; quantum mechanics; lipophilicity; dipole moment; molecular volume; intracellular molecular structures; molecular structure design; alkali metal ions; lipid membranes.

DOI: 10.1504/IJCBDD.2016.078284

International Journal of Computational Biology and Drug Design, 2016 Vol.9 No.3, pp.228 - 246

Received: 16 Sep 2015
Accepted: 06 Nov 2015

Published online: 14 Aug 2016 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article