杂合抗菌肽牛乳铁蛋白素-天蚕素在大肠杆菌中的高效表达及其活性鉴定

【目的】菌株耐药性问题日益突出,研制新型安全高效的抗菌药物成为目前的研究热点之一。抗菌肽具有多种优良特性,高活性抗菌肽的开发及其重组表达对解决菌株耐药性问题具有重要意义。【方法】根据牛乳铁蛋白素与天蚕素的结构,设计一种新型的杂合抗菌肽牛乳铁蛋白素-天蚕素(LfcinB-Cecropin),根据Escherichia coli密码子偏爱性合成其编码基因,利用同尾酶法构建含有不同LfcinB-Cecropin基因片段拷贝数的重组表达载体,转化到E.coli BL21(DE3)进行重组表达。【结果】经IPTG诱导,LfcinB-Cecropin融合蛋白成功获得表达。经超声破碎、包涵体纯化、甲酸裂解后,获得具有明显抑菌活性的杂合肽LfcinB-Cecropin。【结论】获得一种高活性的新型抗菌肽LfcinB-Cecropin,并实现了在E.coli中的高效重组表达。

High-level expression of a hybrid antimicrobial peptide LfcinB-Cecropin in Escherichia coli and its activity

Objective] Resistant strains have become increasingly prominent issues, and the development of safe and efficient antimicrobial agents becomes the focus one of researches so far. Antimicrobial peptides possess many attractive features. Exploration and recombinant expression of antimicrobial peptides with high activity have important significance for solving resistant strains problem. Methods] A novel hybrid antimicrobial peptide LfcinB-Cecropin was designed based on the structures of LfcinB and Cecropin. The gene encoding LfcinB-Cecropin was synthesized according to codon preference of E. coli. Tandem expression plasmids contained multicopy tandem LfcinB-Cecropin genes were constructed by the method of isocaudarner, and expressed them in E. coli. Results] LfcinB-Cecropin was successfully expressed as fusion protein by IPTG induction. After sonication, inclusion body purification, formic acid cleavage, the recombinant LfcinB-Cecropin was obtained and showed obvious antibacterial activity. Conclusion] A novel antimicrobial peptide LfcinB-Cecropin was obtained and recombinantly expressed in E. coli in high level.