J Interferon Cytokine Res 1997 Jul;17(7):377-385
Biochemical evidence for a novel low molecular weight 2-5A-dependent RNase
L in chronic fatigue syndrome.
Suhadolnik RJ, Peterson DL, O'Brien K, Cheney PR, Herst CV, Reichenbach NL,
Kon N, Horvath SE, Iacono KT, Adelson ME, Meirleir KD, Becker PD, Charubala
R, Pfleiderer W
Department of Biochemistry, Temple University School of Medicine,
Philadelphia, PA, USA.
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.