The Jo-1 antigen is histidyl-transfer ribonucleic acid (t-RNA) synthetase. This enzyme is partially responsible for attaching t-RNA to their cognate rRNA (2). The Jo-1 antigen migrates as a 53 kD protein on SDS-PAGE.
Anti-Jo-1 autoantibodies were originally described as precipitating autoantibodies in sera of patients with polymyositis. It was later realized that the anti-Jo-1 antibodies were specific for patients with polymyositis. The target for the anti-Jo-1 antibodies was one of a family of distinct cellular enzymes, the aminoacyl t-RNA synthetases (1).
The presence of autoantibodies against the Jo-1 antigen has been reported in up to 23% of polymyositis patients by immunodiffusion (3). Anti-Jo-1 antibodies are almost completely specific for myositis, being more common in polymyositis than dermato-myositis(4), and rare in children (5). The presence of anti-Jo-1 antibodies defines a distinct group of polymyositis patients with interstitial disease, arthritis, and fevers (6). The anti-Jo-1 response appears to be self-antigen driven, having a broad spectrotype over time undergoing isotype switching. Anti-Jo-1 antibodies also inhibit the function of human histidyl tRNA synthetase more than they do from other species (6).
Recent developments in ELISA meology have increased the sensitivity therefore the diagnostician's ability to quantitate patient antibody titers.
Application:Recommended for use in standard solid phase immunoassays.
Unit Definition: One unit of activity is the amount of antigen that will generate an absorbance of 1.2 when assayed using standard procedure for enzyme immunoassay. Activity will vary with assay conditions/protocols.
Storage Conditions:Product unstable above 0°C, aliquot and store frozen at -70°C. Avoid repeated freeze-thaw.
仕様
Size:1000U
Source Antigen:Calf and/or rabbit thymus
Grade:Purified
Purity:Purified from calf and/or rabbit thymus through the use of immobilized human anti-Jo-1 immune globulins. Other antigens (Sm, RNP, SSA, Scl-70, and SSB) are not detected with ELISA assays. Homogeneity is verified by SDS PAGE.
Form:Supplied as a frozen liquid in 0.01M Tris, 0.5M sodium chloride, 0.02% sodium azide, 50% glycerol.