Bara J, Gautier R, Le Pendu J, Oriol R
Institut de Recherches sur le Cancer, C.N.R.S., Villejuif, France.
Biochem J. 1988 Aug 15;254(1):185-93. doi: 10.1042/bj2540185.
Seven monoclonal antibodies (MAbs) reacting with high-molecular-mass components (greater than 20,000 kDa) isolated from an ovarian mucinous cyst of an A Le(a-b+) patient are described. By the use of immunoradiometric methods, these MAbs characterized seven different epitopes associated with components having a density of 1.45 g/ml by CsCl-density-gradient ultracentrifugation, like mucins. Two MAbs reacted with A and Lewis blood-group antigens respectively (polysaccharide epitopes). The five other MAbs characterized five M1 epitopes (called a, b, c, d and e), mainly associated with components of more than 20,000 kDa and 2000 kDa. They were completely destroyed by papain and 2-mercaptoethanol treatment (polypeptide epitopes). Moreover, timed trypsin digestion of native mucin resulted in a progressive loss of M1 activity and degraded these mucins into smaller M1-positive fragments. The a and c epitopes were partially degraded from relatively high-molecular-mass fragments (2000 kDa to 500 kDa) into a 100 kDa fragment. The b and d epitopes were completely degraded into smaller fragments ranging from 100 kDa to 40 kDa. The e epitope was completely destroyed by trypsin. These different pathways of M1 antigen degradation suggest the occurrence of different epitopes located in separate regions of the mucin molecules.
本文描述了七种单克隆抗体（MAb），它们可与从一名A Le(a-b+)患者的卵巢黏液囊肿中分离出的高分子量成分（大于20,000 kDa）发生反应。通过免疫放射分析方法，这些单克隆抗体鉴定出了七种不同的表位，这些表位与通过氯化铯密度梯度超速离心法测得密度为1.45 g/ml的成分相关，类似黏蛋白。两种单克隆抗体分别与A和Lewis血型抗原发生反应（多糖表位）。另外五种单克隆抗体鉴定出了五个M1表位（称为a、b、c、d和e），主要与分子量超过20,000 kDa和2000 kDa的成分相关。它们在木瓜蛋白酶和2-巯基乙醇处理后完全被破坏（多肽表位）。此外，对天然黏蛋白进行定时胰蛋白酶消化会导致M1活性逐渐丧失，并将这些黏蛋白降解为较小的M1阳性片段。a和c表位从相对高分子量片段（2000 kDa至500 kDa）部分降解为100 kDa片段。b和d表位完全降解为100 kDa至40 kDa的较小片段。e表位被胰蛋白酶完全破坏。M1抗原降解的这些不同途径表明，在黏蛋白分子的不同区域存在不同的表位。
