摘要 目的：构建抗肺腺癌的单链抗体(scFv)，研究其表达条件，为将这一小分子抗体应用于临床奠定基础。方法：将抗人肺腺癌单克隆抗体的重链及轻链可变区基因插入表达载体pFUW80、pTH、pTF，分别在大肠杆菌XL1-Blue、Top10、GI698/GI724中诱导表达，得到噬菌体抗体或包涵体。用SDS-PAGE和ELISA鉴定检测活性。结果： SDS-PAGE的结果表明，在pTH和pTF的表达产物中，有一条43 kD的特异条带，其分子量与预期相符，单链抗体以包涵体形式出现，其表达量达细菌总蛋白的18.6%。ELISA的结果表明，噬菌体抗体和经复性处理的包涵体具有与亲本单抗相同的特异性。结论：成功地构建和在大肠杆菌中表达了抗肺腺癌单链抗体。

Abstract Objectives: To construct a single-chain antibody (scFv) against lung adenocarcinoma and research its expressing conditions for establishing a clinical base. Methods: The variable genes of McAb anti-human lung adenocarcinoma, which were cloned from hybridoma cell WLA-2C4, were inserted into phagemid pFUW80 and expressed scFv in XL1-Blue. Also the scFv genes were inserted into another two vectors pTH and pTF. The corresponding host strains were Top10 and GI724/GI698, the inducing agents were IPTG and tryptophan, respectively. SDS-PAGE and ELISA methods were used to assay the expression products-phage antibodies in XL1-Blue and inclusion bodies in Top10 and GI724/GI698. Results: The scFv had the same specificity of the original monoclonal antibody against the antigen of A549 cell. The inclusion bodies were obtained at high yield 18.6% of the total E.coli proteins. Conclusion: A scFv against lung adenocarcinoma was successfully constructed and expressed in E. coli.