Recombinant 70-kD protein used for determination of autoantigenic epitopes recognized by anti-RNP sera.
A panel of high- and low-titre anti-RNP-positive patient sera was tested for reactivity with human snRNP proteins. The U1 snRNP-specific 70-kD peptide was found to be the most prominent RNP antigen recognized by high-titre anti-RNP sera, mainly found in patients with mixed connective tissue disease (MCTD). The reactivity with the 70-kD protein was further analysed with recombinant fusion proteins containing different segments of the protein. One major and two minor antigenic regions were found. Most patient sera, both with high- and low-titre anti-RNP antibodies, only recognized the major region. The most aminoterminal region, showing partial sequence homology with a mouse retroviral p30 gag protein, contained an epitope that was recognized by one serum only.
Department of Medical Cell Genetics, Karolinska Institute, Stockholm, Sweden.
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U
Nyman
I
I
Lundberg
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E
Hedfors
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I
Pettersson
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology*; D015153:Blotting, Western; D003001:Cloning, Molecular; D003240:Connective Tissue Diseases / Q000276:immunology; D000939:Epitopes; D005260:Female; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000276:immunology; D011993:Recombinant Fusion Proteins / Q000276:immunology; D015183:Restriction Mapping; D012261:Ribonucleoproteins / Q000276:immunology*; D017411:Ribonucleoproteins, Small Nuclear
D001323:Autoantibodies; D001324:Autoantigens; D000939:Epitopes; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D012261:Ribonucleoproteins; D017411:Ribonucleoproteins, Small Nuclear