Einarsson R, Rydlander L
BEKI Diagnostics, AB, Stockholm, Sweden.
Anticancer Res. 1997 Jul-Aug;17(4B):3121-4.
A TPS-reactive protein fragment from a human colon adenocarcinoma cell line was purified to electrophoretic homogeneity. N-terminal sequence analysis of the purified 13 kDa protein fragment demonstrated that the component was a fragment of human cytokeratin 18. The M3 monoclonal antibody (detector antibody in the TPS assay) was applied for screening of an expression library. The M3-reactive phage clones were subcloned and PCR amplified. DNA-sequence analysis revealed it to contain a nucleotide fragment corresponding to human cytokeratin 18. Smaller fragment, engineered by PCR and expressed as fusion proteins, demonstrated that the M3 epitope is localized to human cytokeratin 18, amino acid residues 322-340.
从人结肠腺癌细胞系中纯化出一种对组织多肽特异性抗原（TPS）有反应的蛋白片段，达到电泳纯。对纯化后的13 kDa蛋白片段进行N端序列分析，结果表明该成分是人类细胞角蛋白18的一个片段。使用M3单克隆抗体（TPS检测中的检测抗体）筛选表达文库。对与M3反应的噬菌体克隆进行亚克隆并通过聚合酶链反应（PCR）扩增。DNA序列分析显示其包含一个对应于人类细胞角蛋白18的核苷酸片段。通过PCR构建并表达为融合蛋白的较小片段表明，M3表位定位于人类细胞角蛋白18的322 - 340氨基酸残基处。
