Dinucleotide hydrolysis promoted by dinuclear Zn complexes - The effect ofthe distance between Zn ions in the complexes on the hydrolysis rate

The rate of hydrolysis of an RNA dimer, uridylyl(3 ' -->5 ' )uridine (UpU), promoted by dinuclear Zn complexes resulting from a series of ligands with differently spaced Zn ion binding sites, was examined. Although the ligand s in the present study have in common two di-2-pyridylmethylamino moieties as the Zn binding sites, the activities of these ligands toward the hydroly sis were quite different. Our results suggest that the distance between met al ion coordination sites is an essential factor for the intrinsic activiti es of the dinuclear complexes.