Bélanger A, Rong P M, Liu S, Lavoie L, Labrie F
Laboratory of Molecular Endocrinology, CHUL Research Center, Québec City, Québec.
Clin Invest Med. 1993 Dec;16(6):409-14.
Monoclonal and polyclonal antibodies were produced using a pure preparation of prostate-specific antigen (PSA) as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). By SDS-PAGE, the apparent molecular weight of PSA was about 33 kD. Eighty-four monoclonal antibodies were produced, 77 of which bind PSA with an affinity higher than 10(9) M-1. Use of these monoclonal antibodies to study the immunological characteristics of PSA revealed the presence of 4 epitopes. Injection of PSA into goats resulted in a production of polyclonal antibodies with high affinity. These polyclonal antibodies were purified by affinity chromatography and adsorbed on plastic tubes. By an immunometric assay, we have also demonstrated that polyclonal antibodies bind PSA at a fifth epitope that is different from those of monoclonal antibodies. Using an iodinated monoclonal antibody and polyclonal antibodies adsorbed on plastic tubes, a sensitive immunoradiometric assay could be developed, and a further increase in sensitivity could be achieved by using a mixture of 2 monoclonal antibodies. The serum PSA levels in 2,250 patients measured with this immunoradiometric assay were identical to the values determined by Tandem-R, although the present assay reached a minimum detectable value of 0.05 ng/ml compared with 0.2 ng/ml by Tandem-R.
采用十二烷基硫酸钠 - 聚丙烯酰胺凝胶电泳（SDS - PAGE）测定的前列腺特异性抗原（PSA）纯品制备单克隆抗体和多克隆抗体。通过SDS - PAGE，PSA的表观分子量约为33 kD。制备了84种单克隆抗体，其中77种与PSA的结合亲和力高于10⁹ M⁻¹。使用这些单克隆抗体研究PSA的免疫特性，发现存在4个表位。将PSA注射到山羊体内可产生高亲和力的多克隆抗体。这些多克隆抗体通过亲和层析纯化并吸附在塑料管上。通过免疫分析，我们还证明多克隆抗体在与单克隆抗体不同的第五个表位结合PSA。使用碘化单克隆抗体和吸附在塑料管上的多克隆抗体，可以开发出一种灵敏的免疫放射分析方法，通过使用两种单克隆抗体的混合物可以进一步提高灵敏度。用这种免疫放射分析方法测定的2250例患者的血清PSA水平与Tandem - R测定的值相同，尽管本方法的最低检测值为0.05 ng/ml，而Tandem - R为0.2 ng/ml。
