SUPRAMOLECULAR COMPLEXES OF TRANSITION-METAL(II) IONS FOR THE HYDROLYSIS OF PHOSPHATE-ESTERS AND OF DNA

Complexes from Cu, Ni, Cd and Zu with ethylenediamine and propylenedia mine derivatives were used to study hydrolysis kinetics. With bis- and mono-nitrophenyl phosphates as substrates rate enhancements were foun d which exceed known catalysts by an order of magnitude and more, depe nding on the chosen metal and ligand; the experimentally observed rate accelerations reach up to 5x10(6). Reactions with plasmid supercoiled DNA also show the highest hydrolytic activity achieved until now with transition-metal(II) complexes, with exceptions characterized by a pa rallel to the results with nitrophenyl phosphates. With few exceptions the introduction of positively charged ammonium centers in the ligand side arms leads to significantly enhanced catalytic activity. Prelimi nary affinity and melting point investigations with calf thymus DNA sh ow that with DNA this can be the effect of increased affinity to the n egatively charged grooves.