Abstract |
Recently we described the generation of the prostate tissue-specific monoclonal antibody ( MAb) 107-1A4, its expression pattern and preliminary targeting of human prostate cancer xenografts. In this report we demonstrate that the target antigen for MAb 107-1A4 is prostate-specific membrane antigen (PSMA) using immunoaffinity absorption followed by SDS-PAGE and mass spectrometric analysis of peptides produced by in-gel tryptic digestion. The identity of the antigen has been confirmed by Western blots using MAbs of known specificity. MAb 107-1A4 is not reactive on Western blots. The conformational epitope for 107-1A4 is on the extracellular domain of PSMA. In competition studies, the binding of MAb 107-1A4 to LNCaP cells is inhibited by itself but not by any other of several other anti-PSMA MAbs, suggesting that the epitope may be unique. These results suggest that 107-1A4 is reactive to a conformational epitope in the external domain of PSMA that is unique among the panel of anti-PSMA MAbs in this study. Furthermore this work demonstrates the ability of mass spectroscopy to elucidate antibody- ligand interaction.
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Authors | S Wang, D L Diamond, G M Hass, R Sokoloff, R L Vessella |
Journal | International journal of cancer
(Int J Cancer)
Vol. 92
Issue 6
Pg. 871-6
(Jun 15 2001)
ISSN: 0020-7136 [Print] United States |
PMID | 11351309
(Publication Type: Journal Article)
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Copyright | Copyright 2001 Wiley-Liss, Inc. |
Chemical References |
- 107-1A4 monoclonal antibody
- Antibodies, Monoclonal
- Antigens, Surface
- Epitopes
- Ligands
- Carboxypeptidases
- FOLH1 protein, human
- Glutamate Carboxypeptidase II
- Trypsin
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Topics |
- Antibodies, Monoclonal
(analysis, chemistry)
- Antigens, Surface
- Binding, Competitive
- Blotting, Western
- Carboxypeptidases
(chemistry)
- Electrophoresis, Agar Gel
- Electrophoresis, Polyacrylamide Gel
- Epitopes
- Glutamate Carboxypeptidase II
- Humans
- Ligands
- Mass Spectrometry
(methods)
- Oligonucleotide Array Sequence Analysis
- Precipitin Tests
- Protein Binding
- Protein Conformation
- Protein Structure, Tertiary
- Trypsin
(metabolism)
- Tumor Cells, Cultured
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