Relationship between autoepitope and DNA-binding site on a histone H1 molecule.
Autoepitope and DNA-binding domain on a histone H1 molecule were compared using truncated histone H1 peptides as antigens. At least two epitopes (epitope A, N-terminal side; epitope B, C-terminal side) were found both of which were composed of approximately 20 amino acids. IgM from all 17 anti-histone H1-positive SLE sera reacted with epitope A. IgG from 12 sera reacted with epitope A and IgG from 4 sera reacted with epitope B. In one case, no IgG anti-histone H1 reactivities were found while IgM from the same patient reacted with epitope A. Epitope A had the ability to bind DNA. The reactivities against histone H1 of affinity-purified antiepitope A autoantibodies were inhibited by DNA. These data suggest that some anti-histone H1 antibodies are directed against a histone H1 DNA-binding site, raising the possibility that an idiotype/anti-idiotype network, at least in part, is involved in the generation of anti-histone H1 autoantibodies.
D015551:Autoimmunity; D001665:Binding Sites; D004247:DNA / Q000378:metabolism; D000939:Epitopes / Q000737:chemistry*; D006657:Histones / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*
D000939:Epitopes; D006657:Histones; D004247:DNA