Mapping of epitopes on the SmD molecule: the use of multiple antigen peptides to measure autoantibodies in systemic lupus erythematosus.
Autoantibodies against the ribonucleoproteins B, B' and D are a serological marker of systemic lupus erythematosus (SLE). We mapped the epitopes recognized by autoantibodies on the SmD molecule by means of 7 synthetic peptides corresponding to the entire length of the protein. By ELISA assay, 25% of the lupus sera contained IgG antibodies specific for the C-terminal SmD sequence 95-119. This reactivity was confirmed by synthesizing the sequence as a multiple antigen peptide (MAP): antibodies reactive with the MAP 95-119 were present only in SLE and not in other connective tissue disorders. Sera containing high titers of anti-MAP 95-119 antibodies reacted in immunoblot with the SmD protein. These results indicate the presence of a dominant epitope in the C-terminal region of SmD, which is highly homologous to the Epstein-Barr virus induced nuclear protein EBNA I.
Sabbatini
A
A
Clinical Immunology Unit, University of Pisa, Italy.
Dolcher
M P
MP
Marchini
B
B
Bombardieri
S
S
Migliorini
P
P
D000595:Amino Acid Sequence; D000941:Antigens / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis*; D001324:Autoantigens / Q000235:genetics / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D006801:Humans; D015151:Immunoblotting; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D017411:Ribonucleoproteins, Small Nuclear / Q000276:immunology*; D055517:snRNP Core Proteins
D000941:Antigens; D001323:Autoantibodies; D001324:Autoantigens; D000939:Epitopes; D010455:Peptides; D017411:Ribonucleoproteins, Small Nuclear; D055517:snRNP Core Proteins