Inhibition of oncornavirus functions by poly (2-methylthioinosinic acid)

Nucleic Acids Res. 1975 Dec;2(12):2305-13. doi: 10.1093/nar/2.12.2305.


Poly (2-methylthioinosinic acid) [poly(ms2I)] was found to markedly inhibit the RNA directed DNA polymerase (reverse transcriptase) activity of murine (Moloney, Rauscher) leukemia virus and murine (Moloney) sarcoma virus, while under the same conditions the unsubstituted parent compound poly(I) showed little, if any, inhibitory effect. Copolymers of inosinic acid (I) and 2-methylthioinosinic acid2(ms2I) showed an intermediary effect, depending on the I:ms2I ratio. Poly(ms2I) also inhibited the transformation of normal cells by murine (Moloney) sarcoma virus, as assessed by an infectious center assay.

MeSH terms

  • Cell Transformation, Neoplastic / drug effects
  • Cell Transformation, Viral / drug effects
  • Gammaretrovirus / drug effects*
  • Inosine / analogs & derivatives*
  • Methylthioinosine / pharmacology*
  • Moloney murine leukemia virus / drug effects
  • Moloney murine leukemia virus / metabolism
  • Poly I / analogs & derivatives
  • Poly I / pharmacology*
  • Polyribonucleotides / pharmacology*
  • Rauscher Virus / drug effects
  • Rauscher Virus / metabolism
  • Reverse Transcriptase Inhibitors
  • Sarcoma Viruses, Murine / drug effects
  • Sarcoma Viruses, Murine / metabolism


  • Polyribonucleotides
  • Reverse Transcriptase Inhibitors
  • Poly I
  • Methylthioinosine
  • Inosine