Metal ion-directed DNA recognition by chelating DNA ligands.

Novel DNA ligand bearing oxine and pyridinium group has been synthesized. The DNA binding of this ligand was regulated by coexisting Cu2+ over the range of more than three orders in magnitude of binding constant. This should be due to the metal-mediated dimerization of the ligand and concomitant emergence of cationic charges. There were definite two DNA binding modes for the ligand dimer depending on the P/L ratio.