Biochemical evidence for a novel low molecular weight 2-5A-dependent RNase L in chronic fatigue syndrome

J Interferon Cytokine Res. 1997 Jul;17(7):377-85. doi: 10.1089/jir.1997.17.377.


Previous studies from this laboratory have demonstrated a statistically significant dysregulation in several key components of the 2',5'-oligoadenylate (2-5A) synthetase/RNase L and PKR antiviral pathways in chronic fatigue syndrome (CFS) (Suhadolnik et al. Clin Infect Dis 18, S96-104, 1994; Suhadolnik et al. In Vivo 8, 599-604, 1994). Two methodologies have been developed to further examine the upregulated RNase L activity in CFS. First, photoaffinity labeling of extracts of peripheral blood mononuclear cells (PBMC) with the azido 2-5A photoaffinity probe, [32P]pApAp(8-azidoA), followed by immunoprecipitation with a polyclonal antibody against recombinant, human 80-kDa RNase L and analysis under denaturing conditions. A subset of individuals with CFS was identified with only one 2-5A binding protein at 37 kDa, whereas in extracts of PBMC from a second subset of CFS PBMC and from healthy controls, photolabeled/immunoreactive 2-5A binding proteins were detected at 80, 42, and 37 kDa. Second, analytic gel permeation HPLC was completed under native conditions. Extracts of healthy control PBMC revealed 2-5A binding and 2-5A-dependent RNase L enzyme activity at 80 and 42 kDa as determined by hydrolysis of poly(U)-3'-[32P]pCp. A subset of CFS PBMC contained 2-5A binding proteins with 2-5A-dependent RNase L enzyme activity at 80, 42, and 30 kDa. However, a second subset of CFS PBMC contained 2-5A binding and 2-5A-dependent RNase L enzyme activity only at 30 kDa. Evidence is provided indicating that the RNase L enzyme dysfunction in CFS is more complex than previously reported.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 2',5'-Oligoadenylate Synthetase / metabolism*
  • Adult
  • Antibody Specificity
  • Carrier Proteins
  • Case-Control Studies
  • Endoribonucleases / immunology
  • Endoribonucleases / metabolism*
  • Fatigue Syndrome, Chronic / enzymology*
  • Female
  • Humans
  • Hydrolysis
  • Leukocytes, Mononuclear / enzymology
  • Male
  • Middle Aged
  • Molecular Weight
  • Precipitin Tests
  • Recombinant Proteins / immunology
  • Up-Regulation


  • Carrier Proteins
  • Recombinant Proteins
  • 2',5'-Oligoadenylate Synthetase
  • Endoribonucleases
  • 2-5A-dependent ribonuclease