title: Identification of a novel antimicrobial peptide from amphioxus Branchiostoma japonicum by in silico and functional analyses.
abstract: The emergence of multi-drug resistant (MDR) microbes leads to urgent demands for novel antibiotics exploration. We demonstrated a cDNA from amphioxus Branchiostoma japonicum, designated Bjamp1, encoded a protein with features typical of antimicrobial peptides (AMPs), which is not homologous to any AMPs currently discovered. It was found that Bjamp1 was expressed in distinct tissues, and its expression was remarkably up-regulated following challenge with LPS and LTA. Moreover, the synthesized putative mature AMP, mBjAMP1, underwent a coil-to-helix transition in the presence of TFE or SDS, agreeing well with the expectation that BjAMP1 was a potential AMP. Functional assays showed that mBjAMP1 inhibited the growth of all the bacteria tested, and induced membrane/cytoplasmic damage. ELISA indicated that mBjAMP1 was a pattern recognition molecule capable of identifying LPS and LTA. Importantly, mBjAMP1 disrupted the bacterial membranes by a membranolytic mechanism. Additionally, mBjAMP1 was non-cytotoxic to mammalian cells. Collectively, these data indicate that mBjAMP1 is a new AMP with a high bacterial membrane selectivity, rendering it a promising template for the design of novel peptide antibiotics against MDR microbes. It also shows for the first time that use of signal conserved sequence of AMPs is effective identifying potential AMPs across different animal classes.
authors.affiliation: Laboratory for Evolution &Development, Institute of Evolution &Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Haohan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Laboratory for Evolution &Development, Institute of Evolution &Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Lei
authors.affiliation: Laboratory for Evolution &Development, Institute of Evolution &Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Du
authors.affiliation: Laboratory for Evolution &Development, Institute of Evolution &Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Cui
authors.affiliation: Laboratory for Evolution &Development, Institute of Evolution &Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002942:Circular Dichroism; D030541:Databases, Genetic; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D064175:Lancelets / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D051379:Mice; D008826:Microbial Sensitivity Tests; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D011485:Protein Binding; D013682:Teichoic Acids / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides; D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid