Henan Joint International Research Laboratory of Veterinary Biologics Research and Application, School of Biotechnology and Food Science, Anyang Institute of Technology, No.73 Huanghe Road, Anyang, Henan, 225009, People's Republic of China.
BMC Microbiol. 2020 Aug 1;20(1):233. doi: 10.1186/s12866-020-01925-1.
The recent emergence of antibiotic-resistant strains of bacteria has increased the need to develop effective alternatives to antibiotics. Antimicrobial peptides have been considered as a promising product with several advantages.
In this present study, we identified a novel cecropin from the armyworm, Mythimna separata (armyworm cecropin 1, AC-1) by transcriptome sequencing and multi-sequence alignment analysis. The AC-1 precursor comprised 63 amino acid residues, containing a conserved cleavage site of the signal peptide, Ala-Pro, while the mature AC-1 included 39 amino acid residues. Chemically synthesized AC-1 exhibited low hemolytic activity against chicken red blood cells, low cytotoxicity against swine testis cells, and effective antimicrobial activity against Salmonella, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa. Its antimicrobial activity against Salmonella remained after incubation for 1 h at 100 °C or in 250 mM NaCl, KCl, or MgCl solution, implying good thermal- and salt-resistant stabilities. The bactericidal effect of AC-1 on E. coli gradually increased with increasing AC-1 concentration, resulting in deformation, severe edema, cytolysis, cell membrane damage, and reducing intracellular electron density. Additionally, recombinant AC-1 protein expressed in E. coli was digested by enterokinase protease to obtain AC-1, which showed similar antimicrobial activity against E. coli to chemically synthesized AC-1.
This study identified a novel antimicrobial peptide that may represent a potential alternative to antibiotics.
最近出现的抗生素耐药细菌菌株增加了开发有效抗生素替代品的需求。抗菌肽被认为是一种有前途的产品，具有多个优点。
在本研究中，我们通过转录组测序和多序列比对分析，从粘虫（Mythimna separata）中鉴定出一种新型抗菌肽，即行军虫抗菌肽 1（armyworm cecropin 1，AC-1）。AC-1 前体由 63 个氨基酸残基组成，包含信号肽的保守切割位点 Ala-Pro，而成熟的 AC-1 包含 39 个氨基酸残基。化学合成的 AC-1 对鸡红细胞的溶血活性较低，对猪睾丸细胞的细胞毒性较低，对沙门氏菌、大肠杆菌、肺炎克雷伯菌和铜绿假单胞菌具有有效的抗菌活性。其对沙门氏菌的抗菌活性在 100°C 孵育 1 小时或在 250mM NaCl、KCl 或 MgCl 溶液中保持不变，表明具有良好的热稳定性和耐盐性。AC-1 对大肠杆菌的杀菌作用随着 AC-1 浓度的增加而逐渐增强，导致细胞变形、严重水肿、细胞溶解、细胞膜损伤和细胞内电子密度降低。此外，在大肠杆菌中表达的重组 AC-1 蛋白被肠激酶蛋白酶消化以获得 AC-1，其对大肠杆菌的抗菌活性与化学合成的 AC-1 相似。
本研究鉴定出一种新型抗菌肽，可能代表抗生素的潜在替代品。
