抗菌肽magaininⅡ对E.coli杀伤作用的AFM观察  

Effects of the antimicrobial peptide magaininⅡon Escherichia coli observed by atomic force microscopy

作　　者：王云起[1] 蔡继业[1] 马淑媛[2] 张欣[3] 

机构地区：[1]暨南大学化学系,广东广州510632 [2]暨南大学医学院第一附属医院,广东广州510632 [3]暨南大学生物工程系,广东广州510632

出　　处：《电子显微学报》2006年第1期52-56,共5页Journal of Chinese Electron Microscopy Society

基　　金：国家973项目(No.2001CB510101);国家自然科学基金重点项目(No.30230350);国家自然科学基金面上项目No.60278014)~~

摘　　要：利用原子力显微镜(AFM)观察了不同浓度magaininⅡ对E.coli的作用效果。分别用低于MIC和高于MIC浓度的magaininⅡ作用E.coliD31,结果发现当magaininⅡ浓度低于最低抑制浓度MIC时,细菌外膜的粘弹性增大,膜表面产生数量、大小不等的囊泡结构。当magaininⅡ高于MIC时,细胞很快破损,胞浆内容物外泄,菌体破裂导致死亡。推测magaininⅡ分子可能以“地毯”模式迅速集结于细胞膜上,环绕菌体切断细胞膜。这些结果都说明微生物的细胞膜结构是抗菌肽攻击的首要靶点。The biological effects of magainin Ⅱ on Escherichia coli were investigated by imaging the cells with atomic force microscopy. Two concentrations of magainin Ⅱ , lower and higher than the minimal inhibitory concentration （MIC） respectively, were applied to E. coli cells and distinct differences of morphology changes were observed. When treated with magainin Ⅱ at the concentration lower than the MIC, the viscosity of cell outer membrane was gradually increased and many blebs were formed on the cell surface. However, when treated with magainin Ⅱ at the concentration higher than the MIC, the cells were quickly damaged and disintegrated. Cell contents began to leak and eventually cells were totally disrupted. It may be the ＂carpet＂ mechanism that magainin Ⅱ quickly aggregated on the membrane like carpet and damaged the membrane. These results indicated bacterial membrane is the main target attacked by antimicrobial peptide.

关 键 词：抗菌肽 大肠杆菌 MAGAININ Ⅱ 地毯模式 原子力显微镜 

分 类 号：Q516[生物学—生物化学]