家蝇抗菌肽的分离纯化及生物学活性

将诱导家蝇提取的家蝇抗菌肽提取物，经凝胶过滤层析和离子交换层析，得到具有抗菌活性的单一峰，质谱结果显示抗菌肽分离物含有4种小肽，相对分子质量678．3～1017．2。家蝇抗菌肽对革兰氏阴性菌（大肠杆菌、巴氏杆菌）的抗菌活性优于革兰氏阳性菌（金黄葡萄球菌、枯草芽孢杆菌），对耐药性巴氏杆菌有较强的抗菌活性，对大肠杆菌的MIC为4．2～8．4mg／L，对耐药性巴氏杆菌的MIC为3．8～7．8mg／L。扫描电镜观察发现，家蝇抗菌肽通过损伤细胞壁使细胞质外流而达到杀菌的目的。家蝇抗菌肽对家兔、鸡、猪、小鼠、番鸭、鹅和家鸭红细胞无溶血反应和凝集反应。‘

Purification and biological activities of a antibacterial peptides from housefly

After antimicrobial peptide extracts induced and extracted from housefly(Musca domestica) were separated by sephadex G-50 and CM-sepharose, a single hill with antimicrobial activity was obtained. By LC/MS/MS analysis, it was showed that purification contained 4 peptides of 678.3-1 017.2. Antimicrobial peptide whose activities against gram-positive were better than against gram-negative bacteria, had strong activity againt P.multocida with drug resistance. MIC of the peptide were 4.2-8.4 mg/L on Escherichia coli, and 3.8-7.8 mg/L on P.multocida. It was found by scanning electron microscope that bacteriocidal actions were accomplished through injurying cell membrane and making cytoplasm flowing out. There were no hemolysis and hemagglution of peptide to red cells of rabbit, chick, pig, rat, muscovy duck, goose and duck.