[5'-S-nucleoside triphosphates. Synthesis and substrate properties in tests with DNA polymerases]

In the course of our investigations on DNA polymerases a synthesis of new triphosphate analogues, 5'-mercapto-5'-deoxythymidine 5'-S-triphosphate and 5'-mercapto-3',5'-dideoxythymidine 5'-S-triphosphate, was brought about starting from 3'-O-acetyl-thymidine and 3'-deoxythymidine, respectively. The former compound proved to be a weak substrate for E. coli DNA polymerase I and AMV reverse transcriptase and inactive towards DNA polymerases alpha from placenta and beta from rat liver. The second synthesized triphosphate was incorporated into DNA chain by none of the tested enzymes. Probable reasons for so strong a decrease in the substrate properties of the prepared compounds are discussed.