Reactivities and Site-Selectivities of Hydrolyses of ATP and UTP Promoted by Metal Complexes of Adenine-Linked Di-2-pyridylamine Derivatives

The reactivities and the site-selectivities of the hydrolyses of ATP and UTP by the catalysts of the metal complexes of adenine-linked di-2-pyridylamine ligands, (Py)2N–(CH2)n–Ade (L: n = 3, 4, 5, and 6), were examined. It was found that these adenine–dipyridylamine coordinated Cu2+ complexes (with 2 : 1 ratios of [CuII(L)]2+ : ATP or [CuII(L)]2+ : UTP) were more reactive for the hydrolyses of ATP and UTP than the complexes of ligands containing other metal ions (Mg2+, Ni2+, and Zn2+) at 40 °C and pH 7.3 (HEPES buffer), as reflected in much higher product ratios of ADP/AMP and UDP/UMP than those of Cu2+ alone. The observed high reactivity and selectivity are interpreted in terms of the base-base stackings between an adenine moiety of ATP or an uracil moiety of UTP and an adenine of the ligands, and of the selective coordination of Cu2+ to oxide ions in phosphate residues in the ternary complexes of ligand–Cu2+–ATP. The Cu2+-complex of di-2-pyridylamine having no adenine moiety, which is the active center ...