Molecular dynamics simulations of valinomycin interactions with potassium and sodium ions in water solvent

The aim of this work is to estimate the value of the electric field (potentials) for the system of valinomycin + К+ and Na+ ions based on a molecular dynamics (MD) study. An analysis has been performed of the interaction processes for the system of valinomycin + К+(Na+) ion in water solvent. It is obtained that capturing a К+(Na+) ion in the valinomycin cavity is not possible for all values of the electric field strength. Each of the two kinds of ions (К+ or Na+) has its own critical electric field associated with ion binding to valinomycin, for which to exist, the ion has to remain localized inside the valinomycin cavity. The results obtained for the electrical potential reveal a stronger valinomycin binding—especially with the potassium ion. Valinomycin’s molecular structure efficiently surrounds the K+ ion, as this structure has to exactly correspond to the K+ ion in size. MD simulation results could be a prerequisite for studying a more complex scenario—for estimating ion transport in the cell membrane or physiological electric potential which is formed in the membrane or inside the cell relative to its surrounding medium.