Western blotting analysis of antibodies to prostate-specific antigen: cross-reactivity with human kallikrein-2.
Immunoassays for prostate-specific antigen (PSA) using monoclonal or polyclonal antibodies have clinical applications, such as monitoring and early detection of prostate cancer. However, PSA shares 80% sequence homology with human glandular kallikrein (hK2). In the present study, we have used SDS-PAGE and Western blotting of a recombinant form of hK2 to determine the degree of cross-reactivity in a panel of 83 antibodies submitted to the ISOBM TD-3 PSA Workshop. From this panel, 24 of the 83 antibodies showed cross-reactivity with hK2. The majority of these antibodies showed binding to conformationally independent or linear epitopes. Fourteen of these antibodies appear to map to the same epitope group, indicating the existence of a dominant and linear immunogenic domain shared by PSA and hK2.
Wang
T J
TJ
Department of Research and Development, Hybritech Incorporated, San Diego, Calif 92196-9006, USA. tjwang@beckman.com
Linton
H J
HJ
Rittenhouse
H G
HG
Wolfert
R L
RL
D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000145:classification; D015153:Blotting, Western; D006224:Cricetinae; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes; D006801:Humans; D017430:Prostate-Specific Antigen / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D020840:Tissue Kallikreins / Q000276:immunology*; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000939:Epitopes; D011994:Recombinant Proteins; D020840:Tissue Kallikreins; D017430:Prostate-Specific Antigen