Influence of the position of two dehydro-amino acids residues in the oligopeptide sequence on the binding ability towards Cu(II) ions

Studies on the binding ability of bis-dehydro-hexa- and pentapeptides have shown that the hexapeptides bind Cu+2 with similar efficacy as pentapeptides. The increase of distance between two dehydro-amino acid residues in the peptide backbone has no impact on the efficacy in metal ion binding. The type of isomeration [(Z) or (E)] has an influence on the coordination of the metal ion only to the first amide nitrogen.

The coordination ability towards Cu2+ ion of four bis-dehydro-hexa- and pentapeptides was studied by using potentiometry and spectroscopic methods like UV–Vis and EPR. The studied ligands were: Gly–(Z)ΔPhe–Gly–(Z)ΔPhe–Ala, Gly–(Z)ΔPhe–Gly–Gly–(Z)ΔPhe–Gly, Gly–(E)ΔPhe–Gly–Gly–(E)ΔPhe–Gly and Gly–ΔAla–Gly–Gly–ΔAla–Gly.Figure optionsDownload as PowerPoint slide