LANTHANIDE IONS FOR THE HYDROLYSIS OF 5'-MONONUCLEOTIDES AND 3'-MONONUCLEOTIDES

Cleavage of adenosine-5'-monophosphate (5'-AMP), guanosine-5'-monophos phate (5'-GMP), adenosine-3'-monophosphate (3'-AMP) and guanosine-3'-m onophosphate (3'-GMP) by lanthanides was investigated by NMR and the m ethod of measuring the liberated phosphates. Rapid cleavage of both 5' -mononucleotides and 3'-mononucleotides by Ce-III and Ce-IV under air at pH 9 and 37 degrees C was observed. Other lanthanides showed less e fficiency for hydrolyzing 5'-mononucleotides but 3'-mononucleotides we re catalyzed by a range of lanthanide ions. The mechanism for hydrolyz ing 3'-mononucleotides by lanthanides was:investigated. The notable di fference in reactivity between Ce-III and the other lanthanide ions un der air was further studied showing that the cleavage is enhanced with increasing molar fraction of Ce-IV. The fast cleavage of mononucleoti des by Ce-III under air at pH 9 is ascribed to the resultant Ce-IV in the reaction mixture. (C) 1997 Elsevier Science Ltd.