Xu Wei, Zhu Xin, Tan Tingting, Li Weizhong, Shan Anshan
Laboratory of Molecular Nutrition and Immunity, Institute of Animal Nutrition, Northeast Agricultural University, Harbin, Heilongjiang, China.
PLoS One. 2014 Jun 19;9(6):e98935. doi: 10.1371/journal.pone.0098935. eCollection 2014.
Antimicrobial peptides have attracted considerable attention because of their broad-spectrum antimicrobial activity and their low prognostic to induce antibiotic resistance which is the most common source of failure in bacterial infection treatment along with biofilms. The method to design hybrid peptide integrating different functional domains of peptides has many advantages. In this study, we designed an embedded-hybrid peptide R-FV-I16 by replacing a functional defective sequence RR7 with the anti-biofilm sequence FV7 embedded in the middle position of peptide RI16. The results demonstrated that the synthetic hybrid the peptide R-FV-I16 had potent antimicrobial activity over a wide range of Gram-negative and Gram-positive bacteria, as well as anti-biofilm activity. More importantly, R-FV-I16 showed lower hemolytic activity and cytotoxicity. Fluorescent assays demonstrated that R-FV-I16 depolarized the outer and the inner bacterial membranes, while scanning electron microscopy and transmission electron microscopy further indicated that this peptide killed bacterial cells by disrupting the cell membrane, thereby damaging membrane integrity. Results from SEM also provided evidence that R-FV-I16 inherited anti-biofilm activity from the functional peptide sequence FV7. Embedded-hybrid peptides could provide a new pattern for combining different functional domains and showing an effective avenue to screen for novel antimicrobial agents.
抗菌肽因其广谱抗菌活性以及诱导抗生素耐药性的可能性较低而备受关注，抗生素耐药性是细菌感染治疗失败（与生物膜一起）最常见的原因。设计整合不同肽功能域的杂合肽的方法具有许多优点。在本研究中，我们通过将功能性缺陷序列RR7替换为嵌入肽RI16中间位置的抗生物膜序列FV7，设计了一种嵌入型杂合肽R-FV-I16。结果表明，合成的杂合肽R-FV-I16对多种革兰氏阴性菌和革兰氏阳性菌具有强大的抗菌活性以及抗生物膜活性。更重要的是，R-FV-I16表现出较低的溶血活性和细胞毒性。荧光测定表明，R-FV-I16使细菌的外膜和内膜去极化，而扫描电子显微镜和透射电子显微镜进一步表明，该肽通过破坏细胞膜杀死细菌细胞，从而损害膜的完整性。扫描电子显微镜的结果还提供了证据，证明R-FV-I16从功能性肽序列FV7继承了抗生物膜活性。嵌入型杂合肽可为组合不同功能域提供一种新模式，并为筛选新型抗菌剂提供一条有效途径。
