title: Isolation and characterisation of a novel antibacterial peptide from a native swine intestinal tract-derived bacterium.
abstract: Antimicrobial peptides (AMPs) are highly associated with antipathogenic activity, without generating drug resistance in targeted bacteria. In this study, the existence of AMPs in the Tibetan swine, a China-native, cold-resistant and seldom-sick breed of pig, was investigated. A peptide secreted by a Tibetan swine intestinal tract-derived Bacillus strain was isolated using reversed-phase chromatography (RPC), ultrafiltration and reversed-phase high-performance liquid chromatography (RP-HPLC). The peptide was identified by mass spectrometry and was characterised for activity against Escherichia coli and Staphylococcus aureus. The 16-amino acid peptide (ASVVNKLTGGVAGLLK), named TP, had a molecular mass of 1568.919 Da and exhibited inhibitory activity against Gram-positive and Gram-negative bacteria [minimum inhibitory concentrations (MICs) of 2.5-5 µM and 10-20 µM for E. coli and S. aureus, respectively] as well as human MKN-45 and NB4 tumour cell lines [50% inhibitory concentration (IC50) = 4.686 µM and 11.479 µM, respectively]. TP also exhibited weak haemolytic activity. Furthermore, TP enhanced cell membrane permeability and K+outflow, bound with E. coli genomic DNA in vitro and inhibited E. coli growth. Thus, TP represents a strong candidate as an antibacterial peptide.
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Haiyun
authors.initials: H
authors.lastname: Xin
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China; Institute of Animal Sciences of CAAS, No. 2 Yuanmingyuan West Road, Haidian, Beijing 100193, China.
authors.forename: Shengyue
authors.initials: S
authors.lastname: Ji
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Jiayin
authors.initials: J
authors.lastname: Peng
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Han
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: An
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Wang
authors.affiliation: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, Shaanxi 712100, China. Electronic address: caobinyun@126.com.
authors.forename: Binyun
authors.initials: B
authors.lastname: Cao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001407:Bacillus / Q000737:chemistry* / Q000302:isolation & purification; D001688:Biological Products / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002681:China; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D004926:Escherichia coli / Q000187:drug effects*; D041981:Gastrointestinal Tract / Q000382:microbiology*; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects*; D013552:Swine; D014461:Ultracentrifugation
chemical_list: D000900:Anti-Bacterial Agents; D001688:Biological Products; D010455:Peptides
keywords: Antibacterial peptide; Antitumour; MIC; Tibet swine