关键词: 日本血吸虫； 信号传导蛋白14?3?3； 单克隆抗体； 噬菌体随机展示肽库； 模拟表位； 生物淘洗

Abstract:

Objective To identify the epitope of monoclonal antibody (McAb) 5C6 against 14?3?3 protein of Schistosoma ja? ponicum by phage display peptide library. Methods The phage display 12?peptide library was screened with purified McAb 5C6 against 14?3?3 protein of S. japonicum three rounds of bio?panning“adsorption?elution?amplification”to enrich the specific binding phages. The single phage clones selected randomly were amplified，their genomic DNA were extracted and sequenced. The im? mune response characterization of phages with the same or high homologous foreign inserted DNA sequence was identified by ELI? SA and Western blotting for further defining the epitope recognized by McAb 5C6. Results A total of 33 single phage clones were selected and sequenced. Among them，25 shared the same foreign inserted DNA sequence of 5′ ? CCACCTAGTAGCAGACC? GATTCTCAGTCGAAGGAAA?3′，encoding a deduced peptide PPSSRPILSRRK. This peptide was not homologue to Sj14?3?3 pro? tein or any other known native protein in the world. The results of Western blotting showed that this peptide could be recognized by the sera of patients with schistosomiasis，but not by those of healthy persons. Conclusion The mimic antigen epitope of McAb 5C6 against 14?3?3 protein of S. japonicum， which is a conformational epitope，has been defined successfully in this study.

Key words: Schistosoma japonicum；Signal transduction protein 14?3?3；Monoclonal antibody；Phage random display pep? tide library； Mimic epitope；Biopanning