Ion-Pairing Mechanism for the Valinomycin-Mediated Transport of Potassium Ions across Phospholipid Bilayers

The role of the anion on ionophore properties valinomycin was studied in a model floating bilayer lipid membrane (fBLM) using supporting electrolytes containing K+ with four different counter species (ClO4–, H2PO4–, Cl–, and F–). electrochemical impedance spectra indicate that resistance decreases decrease Gibbs free energy solvation. IR demonstrate does not readily bind to KH2PO4, KCl, KF electrolyte solutions, but presence KClO4, binds K+, forming valinomycin–K+ complex. results present paper reveal transport cations by across bilayer. valinomycin–cation complex creates an ion pair anion, this can enter hydrophobic region transporting cation membrane. Anions low solvation energies facilitate formation improving conductivity valinomycin-incorporated bilayers. This sheds new light mechanism ionophores provides information about bioactivity molecule.