5'-DITHIOPHOSPHORYL DEOXYOLIGONUCLEOTIDES - SYNTHESIS AND BIOLOGICAL STUDIES

The first synthesis of 5'-dithiophosphoryl deoxyoligonucleotides is re ported. These oligomers are prepared by reacting O-(9-fluorenemethyl) H-phosphonothioate with an appropriately protected deoxyoligonucleotid e and then oxidizing phosphorus with elementary sulfur. By using S-35- sulfur, a long-lived radioactive isotope that is useful for monitoring biological and biochemical experiments can be introduced into deoxyol igonucleotides. 5'-Dithiophosphoryl deoxyoligonucleotides are stable t oward alkaline phosphatase and do not serve as substrates for T4-polyn ucleotide ligase. These oligomers undergo oxidative phosphoryl disulfi de formation to yield dimers via an intermolecular reaction or with cy steine to generate an amino acid-deoxyoligonucleotide joined through t he 5'-dithiophosphoryl moiety and the cysteine sulfhydryl function.