1H NMR Study of the Enantioselective Binding ofΛ- andΔ-[Ru(bpy)2(m-bpy-GHK)]Cl2to the Deoxynucleotide Duplex d(5'-C1G2C3G4A5A6T7T8C9G10C11G12-3')2

Abstract

The interaction of the diastereomeric complexes Λ- andΔ-[Ru(bpy)2(m-GHK)]Cl2, (GHK = glycine-histidine-lysine) to the deoxynucleotide duplex d(5'-CGCGAATTCGCG-3')2was studied by means of1H NMR spectroscopy. The diastereomers interact with the oligonucleotide duplex differently. TheΔ-[Ru(bpy)2(m-GHK)]Cl2is characterized by major groove binding close to the central part of the oligonucleotide, with both the peptide and the bipyridine ligand of the complex involved in the binding. TheΛ-[Ru(bpy)2(m-bpy-GHK)]Cl2binds loosely, approaching the helix from the minor groove. The NMR analysis shows that the peptide (GHK) binding has a determinative role in the interactions of both diastereomers with the oligonucleotide.