Modeling of Main Characteristics of Bullous Pemphigoid Antigen-2 (BPAG2) Peptide Structure in Serological Recognition by Autoantibodies

József PÁL1, Ilona MARCZINOVITS2, Ferenc HUDECZ3, Gábor K TÓTH4, Gábor MEZÕ3, János MOLNÁR2, Péter NÉMETH1

1Department of Immunology and Biotechnology, University of Pécs, Faculty of Medicine, Pécs, Hungary
2Department of Physiology, University of Szeged, Szeged, Hungary
3Research Group of Peptide Chemistry, Hungarian Academy of Sciences, Eötvös Loránd University, Budapest, Hungary
4Department of Medical Chemistry, University of Szeged, Szeged, Hungary


The serum level of autoantibodies against autoantigens of the bullous pemphigoid peptides 1 and 2 (BPAG1 and BPAG2) is a relevant diagnostic marker. Twelve representative sera of BP were tested against the RSILPYGDSMDRIEKDRLQMAP amino acid sequence that is an epitope fragment of the NC16A domain of BPAG2 (AC Q02802; 507-528) to find the most suitable antigenic form for specific detection of autoantibodies of BP patients’ sera by quantitative ELISA system. The antigenic epitope sequence was presented as an antigen in a carrier free form of dimeric peptide (BP22), dimeric peptide fused to glutathione S-transferase (GST-BP22) or dimeric peptide chemically conjugated to polyLys(Ser-DL-Alam) (SAK-BP22). The intensity of ELISA reaction was highest against the recombinant fusion antigen GSTBP22; the chemically conjugated SAK-BP22 performed less well than the free dimeric form of the peptide. In the case of the GST-BP22 antigen, the (GST-BP22)-(GST)492nm optical density values were determined. There was no significant difference between the mean ODs of the GST-BP22 and the SAK-BP22 (0.888 vs. 0.892, p= 0.9726). Conjugating the epitope peptide with the synthetic carrier SAK was advantageous, as it abrogated cross-reactivity with GST carrier protein. Consequently, the SAKBP22 conjugate appears to be the most reliable assay component, avoiding cross-reactivity with GST and simplifying the detection and evaluation of BP autoantibodies in routine ELISA diagnostic system. Pathology & Oncology Research, Vol 10, Nr 1, 52-56, 2004

Key words: carrier effect; BPAG2 epitope; autoantibodies; immunological recognition; cross-reaction

Received: Feb 3, 2004; accepted: Feb 25, 2004
Correspondence: Péter NÉMETH, Department of Immunology and Biotechnology, University of Pécs, Faculty of Medicine, Szigeti u 12. Pécs H-7643, Hungary; E-mail:

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