Multiple interactions in Zn(II) ternary systems of phenanthroline bridging polyaza ligand and adenosine, 5'-triphosphate

Abstract

The stability of Zn(II) ternary complexes of phenanthroline bridging polyaza ligand and ATP have been determined using potentiometric <i>p</i>H<i> </i>titrations, ¹H and ³¹P NMR spectra. Protonated metal complexes interact with the polyphosphate chain of the nucleotide substrate by coordination, electrostatic and H-bonding interactions, as well as stacking interactions

bctween the phenanthroline moiety of L and the nucleoside residue of ATP. Moreover, ion-π-donor, hydrophobic and even vander Waals interactions may exist in the ternary systems. The recognition of nucleotides is promoted by adding Zn(II) to the receptor/substrate system. Zn(II) acts as n "messenger" to bridge the polyamine and ATP, which in turn leads to

competition between the mixed ligands in binding zinc ion. Thus, the supramolecules formed by self-assembly are good models to mimic the active center of the ATPase.