新型牛乳铁蛋白衍生肽LFcinB-W的抗感染作用

Anti-infection effect of a novel lactoferrin derived peptide LFcinB-W

抗菌肽有望替代抗生素成为一种安全、绿色、高效的理想抗菌剂,牛乳铁蛋白肽(bovine lactoferricin,LFcinB)是由牛乳铁蛋白经消化酶水解产生的一类具有广谱抑菌活性的短肽。文章以牛乳铁蛋白肽为基础,根据抗菌肽结构与功能的关系,对LFcinB的结构进行优化设计得到衍生肽LFcinB-W。将设计得到的LFcinB-W基因片段与pPIC9K质粒构建重组表达载体,转化毕赤酵母细胞GS115诱导表达。对发酵上清液进行分离纯化和活性测试,结果证明该衍生肽对金黄色葡萄球菌、大肠杆菌和枯草芽孢杆菌有更强的抑菌活性;利用病原体Erwinia carotovora carotovora 15(Ecc15)感染模式生物果蝇肠道,进一步探究LFcinB-W对感染模型的保护作用,结果显示LFcinB-W可有效缓解病原体感染对果蝇造成的损伤,在体内表现出比LFcinB更好的抗感染作用,为进一步研究该肽的生物活性及生产应用提供参考。

Antibacterial peptides are expected to replace antibiotics and become a safe,green and efficient ideal antibacterial agent.Bovine lactoferricin(LFcinB)is a kind of short peptide with broad spectrum antibacterial activity produced via hydrolysis of lactoferrin by digestive enzymes.Based on LFcinB,the derivative peptide LFcinB-W was obtained by optimizing the structure of LFcinB according to the relationship between structure and function of antibacterial peptide.The recombinant expression vector was constructed by combining LFcinB-W gene fragment with pPIC9K plasmid,and transformed into Pichia pastoris GS115 cells to induce expression.The fermentation supernatants were separated,purified and tested for antibacterial activity,and the results showed that the peptide had stronger antibacterial activity against Staphylococcus aureus,Escherichia coli and Bacillus subtilis.The model organism Drosophila gut was infected by the pathogen Erwinia carotovora carotovora 15(Ecc15)to investigate the protective effect of LFcinB-W on the infection model,and the results indicated that LFcinB-W could effectively alleviate the damage caused by pathogen infection in Drosophila and showed better anti-infection effect than LFcinB,providing reference for the further study of the biological activity and production and application of LFcinB-W.