抗氯菊酯人源scFv抗体筛选与鉴定

Screening and characterization of human phage antibody to permethrin

目的 筛选氯菊酯人源单链可变区（scFv）抗体,为研究快速检测试剂盒奠定基础.方法 采用噬菌体表面展示技术,以氯菊酯作为抗原,固相包被于Nunc板,应用半合成的人源单链可变区抗体文库技术,从噬菌体单链可变区抗体库中经过3轮＂吸附-洗脱-扩增＂筛选过程,随机挑选抗氯菊酯的100个克隆,利用酶联免疫吸附法（ELISA）、交叉反应及竞争抑制实验,对其进行免疫学检测和鉴定,获得与氯菊酯结合活性较强的scFv阳性克隆,从噬菌体抗体阳性克隆中提取质粒,经酶切鉴定Sfi Ⅰ/Not Ⅰ后,亚克隆到pCANTAB5E载体;转化大肠杆菌XL1-Blue,提取质粒进行酶切鉴定分析.结果 经过筛选100个克隆中有18株克隆ELISA的吸光度（A值）-490 nm波长（A490nm）值较高,将这些噬菌体上清与牛血清白蛋白（BSA）进行交叉反应,确定有5株交叉反应较弱,结合3次ELISA重复实验的A值及竞争抑制实验结果,最后确定1株阳性克隆.亚克隆到pCANTAB5E载体;转化感受态细胞XL1-Blue.结论 提取质粒酶切片段与目的相符;为下一步其特异性亲和力的研究创造了条件.

Objective To screen permethrin human single-chain variable region （scFv） antibody for aims of developing rapid detection kit. Methods Phage display technology was used in this study. Permethrin was solid phase coated on Nunc plate as antigen. Semi-synthetic single-chain variable region of human antibody library technology was applied, and single chain variable region was screened from phage antibody library after 3 rounds ＂adsorption - elution - amplification＂ of the selection process. 100 clones were random selected as resistance to permethrin clones , enzyme-linked immunosorbent assay （ELISA）, crossreactivity and competitive inhibition experiments were used to validate permethrin binding activity with strong scFv clones from the selected phage antibody clones plasmid. The plasmid was digested with restriction enzyme Sfi Ⅰ / Not Ⅰ and subcloned into pCANTAB5E vector. After transformed into E. coli XL1BIue, the plasmid was identified by restriction enzyme analysis. Results After screening in 100 clones, 18 clones had high ELISA absorbance values （ A value） at 490nm wavelength （ A490nm）, then bovine serum albumin （BSA） cross-reactions identified five weak cross-reaction. Combined with the triplicate ELISA and competitive inhibition experiment results, one positive clone was acquired at last. And this clone was subcloned into pCANTAB5E vector and transformed into competent cells XL1-Blue. Conclusion Plasmid fragment was consistent with the purpose, which provided the foundation for further study of its specific affinity.