@article{3023091,
    title = "A diepitopic sequential oligopeptide carrier (SOCn) as mimic of the Sm autoantigen: Synthesis, conformation and biological assays",
    author = "Alexopoulos, C. and Tsikaris, V. and Rizou, C. and Panou-Pomonis, E. and Sakarellos-Daitsiotis, M. and Sakarellos, C. and Vlachoyiannopoulos, P.G. and Moutsopoulos, H.M.",
    journal = "Journal of Peptide Science",
    year = "2001",
    volume = "7",
    number = "2",
    pages = "105-114",
    issn = "1075-2617, 1099-1387",
    doi = "10.1002/psc.302",
    keywords = "amino acid;  antigen sm;  autoantibody;  autoantigen;  carrier protein;  cross reacting antibody;  cross reacting antigen;  epitope;  glycine derivative;  lysine derivative;  oligopeptide;  ribonucleoprotein;  ribonucleoprotein antibody;  RNA;  small nuclear ribonucleoprotein;  tetramer;  unclassified drug, amino acid sequence;  antibody specificity;  article;  bioassay;  conformation;  controlled study;  cross reaction;  diagnostic test;  immunoreactivity;  mixed connective tissue disease;  molecular mimicry;  priority journal;  protein motif;  protein RNA binding;  protein structure;  protein synthesis;  sequence analysis;  structure analysis;  systemic lupus erythematosus, Amino Acids;  Antigens;  Autoantigens;  Binding Sites;  Enzyme-Linked Immunosorbent Assay;  Epitopes;  Humans;  Immunoglobulin G;  Magnetic Resonance Spectroscopy;  Models, Chemical;  Oligopeptides;  Peptide Biosynthesis;  Protein Conformation;  Ribonucleoproteins, Small Nuclear",
    abstract = "Anti-Sm (Sm: U1-U6 RNA-protein complex) antibodies are usually considered highly specific for systemic lupus erythematosus (SLE), while anti-U1RNP (U1RNP: U1RNA-protein complex) are thought of as diagnostic criteria for the mixed connective tissue disease (MCTD). However, both antibody specificities coexist in SLE and MCTD, in varying percentages. Although the anti-Sm/anti-U1RNP immunological cross-reactivity has been initially attributed to a common motif, PPXY(Z)PP (where X, Y, Z are various amino acids), found in the Sm, U1-A and U1-C autoantigens, it appears that the conformational features of the Sm epitopes also play an important role in the immunoreactivity. The PPGMRPP and PPGIRGP main epitopes of the Sm antigen were coupled in duplicate to the tetrameric Ac-(Lys-Aib-Gly)4-OH, SOC4, carrier to form the [(PPGMRPP)2, (PPGIRGP)2]-SOC4 construct as a mimic of the native Sm. It was found that: (i) the 310 helical structure of SOC4 allows the epitopes to adopt an exposed orientation, similar to their free forms, that facilitates their recognition from the anti-Sm antibodies, and (ii) the U1-RNP cross-reactivity is minimized. Copyright © 2001 European Peptide Society and John Wiley & Sons, Ltd."
}