Characterization of valinomycin binding with alkali metal ions by capillary affinity electrophoresis and density functional theory

Capillary affinity electrophoresis (CAE) and quantum mechanical density functional theory (DFT) have been applied to the study of non-covalent binding of valinomycin (Val), an antibiotic dodecadepsipeptide ionophore, with alkali metal ions, Li+, Na+, K+, Rb+ and Cs+, in methanol. The binding constants (Kb) of Val-alkali metal ion complexes were evaluated by CAE. The most probable structures of the Val-alkali metal ion complexes were proposed by DFT