Premium
Involvement of the C‐terminal end of the prostrate‐specific antigen in a conformational epitope: characterization by proteolytic degradation of monoclonal antibody‐bound antigen and mass spectrometry
Author(s) -
Michel Sandrine,
Forest Eric,
Pétillot Yves,
Deléage Gilbert,
HeuzéVourc'h Nathalie,
Courty Yves,
Lascoux David,
Jolivet Michel,
JolivetReynaud Colette
Publication year - 2001
Publication title -
journal of molecular recognition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.401
H-Index - 79
eISSN - 1099-1352
pISSN - 0952-3499
DOI - 10.1002/jmr.552
Subject(s) - epitope , monoclonal antibody , antigen , microbiology and biotechnology , chemistry , peptide sequence , glycoprotein , epitope mapping , antibody , linear epitope , amino acid , biochemistry , peptide , recombinant dna , biology , gene , immunology
Prostate‐specific antigen (PSA), a 237‐amino acid glycoprotein, encoded by the hKLK3 gene, is widely used as a serum marker for the diagnosis and management of prostate cancer. We report here the localization of a conformational epitope recognized by the anti‐total PSA monoclonal antibody (mAb) 11E5C6, by proteolytic degradation of mAb‐bound antigen followed by mass spectrometric analyses of the peptides generated. These two technologies, combined with molecular display, allowed the identification of amino acid residues contained within three different peptides distant on the PSA sequence, but close in the PSA three‐dimensional structure, that may be part of the mAb 11E5C6 epitope. The last four C‐terminal amino acid residues are included in this epitope, as well as certain other C‐terminal residues between Y225 and T232. The involvement of the PSA C‐terminal end in the mAb 11E5C6 epitope was confirmed by western blotting experiments with the recombinant protein proPSA‐RP1, resulting from the cloning of an alternative transcript of the hKLK3 gene, in which the PSA C‐terminal end was deleted and replaced by another sequence. Although the anti‐total PSA mAb 5D5A5 used as a control bound proPSA‐RP1, mAb 11E5C6 did not. The requirement of the C‐terminal end for the recognition by mAb 11E5C6 may be useful for the discrimination of PSA‐related forms. Copyright © 2001 John Wiley & Sons, Ltd.