Lövgren J, Piironen T, Overmo C, Dowell B, Karp M, Pettersson K, Lilja H, Lundwall A
Department of Clinical Chemistry, Lund University, University Hospital, Malmö, Sweden.
Biochem Biophys Res Commun. 1995 Aug 24;213(3):888-95. doi: 10.1006/bbrc.1995.2212.
Measurements of prostate-specific antigen (PSA) in serum are widely used to monitor patients with prostate cancer, but the attenuation of the assay response by PSA complexed to protease inhibitors has been shown to affect the results in certain assay designs. Moreover, the human glandular kallikrein-2 (hK2), a kallikrein-like serine protease that is 80% similar to PSA, might interfere with the specific detection of PSA by immunological cross-reactivity. We have expressed hK2 and PSA in eucaryotic cells using the Semliki Forest Virus expression system and studied the reactivity of 18 monoclonal anti-PSA IgGs. Five of them cross-reacted with identical affinities to recombinant hK2 whereas 13 recognized PSA alone. The antibodies that recognized both PSA and hK2 bind to a region of the protein that is exposed when PSA is complexed to alpha-1-antichymotrypsin.
血清中前列腺特异性抗原（PSA）的检测被广泛用于监测前列腺癌患者，但已证明与蛋白酶抑制剂复合的PSA会使检测反应减弱，从而在某些检测设计中影响结果。此外，人腺激肽释放酶2（hK2）是一种与PSA有80%相似性的激肽释放酶样丝氨酸蛋白酶，可能通过免疫交叉反应干扰PSA的特异性检测。我们使用辛德毕斯病毒表达系统在真核细胞中表达了hK2和PSA，并研究了18种抗PSA单克隆IgG的反应性。其中5种与重组hK2以相同亲和力发生交叉反应，而另外13种仅识别PSA。那些既识别PSA又识别hK2的抗体结合到当PSA与α-1-抗糜蛋白酶复合时暴露的蛋白质区域。
