EFFECTS OF 5-(N-AMINOHEXYL)CARBAMOYL-2'-DEOXYURIDINE ON ENDONUCLEASE STABILITY AND THE ABILITY OF OLIGODEOXYNUCLEOTIDE TO ACTIVATE RNASE-H

To evaluate an endonuclease resistance property of oligodeoxynucleotid es (ODNs) containing 5-(N-aminohexyl)carbamoyl-2'-deoxyuridine (Hs) an d to elucidate whether a duplex consisting of the ODN analogue and its complementary RNA induces RNase H activity, the ODNs containing the d eoxyuridine analogues, Hs, at intervals of one, two, three, four and f ive natural nucleosides were synthesized, From partial hydrolysis of t hese ODNs with nuclease S1 (an endonuclease), it was found that the OD Ns became more stable towards nucleolytic hydrolysis by the enzyme as the number of H increased, Furthermore, to examine whether the duplexe s composed of the ODNs containing Hs and their complementary RNAs are substrates for RNase H or not, the duplexes of these ODNs and their co mplementary RNA strands were treated with Escherichia coli RNase H, It was found that cleavage of the RNA strands by the enzyme was kinetica lly affected by the introduction of Hs into the duplexes.