Jette D C, Kreutz F T, Malcolm B A, Wishart D S, Noujaim A A, Suresh M R
Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, Canada.
Clin Chem. 1996 Dec;42(12):1961-9.
Prostate-specific antigen (PSA) is a widely used marker for screening and monitoring prostate cancer. We identified and characterized the epitopes of two anti-PSA monoclonal antibodies (mAbs) designated B80 and B87. The epitopes were initially mapped as nonoverlapping by developing a sandwich immunoassay to measure PSA with the two anti-PSA mAbs. The two antibodies do not cross-react with homologous pancreatic kallikrein, but recognize epitopes unique to PSA. B80 and B87 can recognize both free and complexed PSA and hence measure total PSA. Epitope scanning and bacteriophage peptide library affinity selection procedures were used to identify and locate an epitope on PSA. A possible epitope for B80 was identified as being located on or near PSA amino acid residues 50-58 (-GRH-SLFHP-). The epitope for B87 was likely on an exposed nonlinear conformational determinant, unique to PSA, and not masked by the binding of B80 or alpha 1-antichymotrypsin.
前列腺特异性抗原（PSA）是一种广泛用于筛查和监测前列腺癌的标志物。我们鉴定并表征了两种抗PSA单克隆抗体（mAb）B80和B87的表位。通过开发一种夹心免疫测定法，用这两种抗PSA单克隆抗体来测量PSA，最初将表位定位为不重叠。这两种抗体与同源胰激肽释放酶不发生交叉反应，但识别PSA特有的表位。B80和B87既能识别游离PSA，也能识别复合PSA，因此可测量总PSA。采用表位扫描和噬菌体肽库亲和选择程序来鉴定和定位PSA上的一个表位。已确定B80的一个可能表位位于PSA氨基酸残基50 - 58（-GRH - SLFHP-）上或其附近。B87的表位可能位于PSA特有的一个暴露的非线性构象决定簇上，且不会被B80或α1 - 抗糜蛋白酶的结合所掩盖。
