Efficient chemical synthesis of AppDNA by adenylation of immobilized DNA-5'-monophosphate.

AppDNA is an intermediate in enzyme-catalyzed DNA ligation reactions, and its efficient enzymatic synthesis requires a donor-template duplex of at least 11 base pairs in length. An efficient chemical synthesis of AppDNA with the coupling of an adenosine 5'-phosphorimidazolidate to an immobilized DNA-5'-monophosphate as the key step is described. The adenylation efficiencies of DNA-5'-monophosphate were excellent for oligonucleotides containing less than 11 nucleotides and at least 50% for oligonucleotides containing 15-25 nucleotides.