密码子优化前后AvBD2成熟肽基因的表达水平及其抑菌活性的比较

Comparison of the expression levels and antibacterial activity between native and codon-optimized gene fragments encoding AvBD2 mature peptides

根据大肠杆菌的密码子偏好性,将编码AvBD2成熟肽的基因原片段Na-AvBD2优化为片段Op-AvBD2,将2条片段分别转化至大肠杆菌中重组表达,表达产物经GST树脂纯化后,对二者的表达水平和抗菌活性进行了比较。结果,融合蛋白rOp-AvBD2的表达量比rNa-AvBD2高2倍。而两者对大肠杆菌(CM-CC44102)、金黄色葡萄球菌(ATCC25923)、鸡白痢沙门氏菌(CVCC533)和粪肠球菌(ATCC29212)的抑菌活性及对鸡白痢沙门氏菌(CVCC533)和粪肠球菌(ATCC29212)菌体超微结构的破坏程度无显著差异。结果提示AvBD2在预防和治疗细菌感染中具有替代抗生素的潜在应用价值,而密码子优化将成为通过基因工程生产AvBDs的可行途径。

Considering Escherichia coli codon bias,Op-AvBD2 was acquired by optimizing Na-AvBD2,the native gene fragment.Both Op and Na AvBD2 fragments were transformed into E.coli for expression,respectively and the products were purified.Then we compared the expression levels and antibacterial activities of both the recombinant Na-AvBD2 and the Op-AvBD2 peptides.In result,the average expression levels of the rOp-AvBD2 peptides were two-fold higher than the average of rNa-AvBD2 peptide.Both peptides were found to have strong properties against E.coli（CMCC44102）,Staphylococcus aureus（ATCC25923）,Salmonella pullorum（CVCC533）,and Enterococcus faecalis（ATCC29212）.Meanwhile,the peptides did not demonstrate bactericidal properties against Pseudomonas aeruginosa（ATCC27853） stains.In addition,the two peptides did not express significantly different bacteriostasis spectrums,MIC values,or the ability to damage the ultrastructure for the same test organisms.The results showed that the AvBD2 could be a potential alternative of antibiotics in the prevention and treatment of bacterial infections,and codon optimization would become a feasible way for producing AvBDs by genetic engineering.