摘要
作者利用饱和硫酸铵沉淀和ＤＥＡＥ５２离子层析柱纯化本中心自制结肠癌单克隆抗体ＭＣ３，以此为配基与Ｓｅｐｈａｒｏｓｅ４Ｂ偶联，经免疫亲和层析从自制可溶性结肠癌抽提液中纯化出一种新的肠癌肿瘤相关抗原ＭＣ３－Ａｇ。其特性分析表明，ＭＣ３－Ａｇ可为高碘酸氧化或强硷水解，而对胰蛋白酶、神经氨酸酶、去糖酯混合液及弱硷处理不敏感，提示其决定簇可能位于Ｎ糖苷键型糖蛋白糖链上。ＳＤＳ－ＰＡＣＥ及免疫印迹分析表明ＭＣ３－Ａｇ的分子量为２８．８ｋＤ。免疫反应分析ＭＣ３－Ａｇ不与ＣＥＡ、ＡＦＰ等已知结肠癌相关抗原的单克隆抗体反应。
The McAb MC3,reactive with human colon carcinoma and generated in our center,was purified from the ascites by precipitation method with saturated ammonium sulfate and passing through chromatograghic column DEAE 52.The purified MC3 was coupled to CNBr-activated Sepliarose 4B.A noyel colon cancer associated antigen,MC3-Ag was isolated from the tissue extract of colonic adenocar cinoma by MC3-immunoaffinity chromatography.MC3-Ag was sensitive to periodic oxidation and strong alkali treatment. but resistant to neuraminidase and protease digestion.This indicates that carbohydrate chain N-liked to protein is probably part of the epitope.The results of SDS-PAGE and immunoblotting studies confirmed that MC3-Ag is 28. 8kD in molecular weight The antigen seems to shown no crossreaction, by immunodot blot assay,with the previously reported tumor-associated antigens such as CEA,AFP,MC5-Ag.MC7-Ag and MC10-Ag.
关键词
结肠肿瘤
抗原
单克隆抗体
Colonic neoplasms
antigens
antibody,monbclonal
affinity chromatography
