title: Two novel antimicrobial peptides purified from the symbiotic bacteria Xenorhabdus budapestensis NMC-10.
abstract: Symbiotic bacteria, which are carried in the intestinal vesicle of the infective stage of juvenile entomopathogenic nematodes, produce broad-spectrum antibiotics. In this study, we aimed to isolate the antimicrobial peptides from the culture of the entomopathogenic bacterium Xenorhabdus budapestensis NMC-10. By screening chromatography columns and optimizing flow rate, pH, salinity and other purification conditions, we identified the final purification procedures which consisted of Q ion-exchange chromatography, gel filtration chromatography and two-step reverse-phase chromatography. Two novel antimicrobial peptides were identified via Q-TOF-TOF and de novo sequencing, and designated as GP-19 and EP-20. Both natural and synthetic peptides demonstrated broad-spectrum antimicrobial activities. The synthetic GP-19 peptide was active against Verticillium dahlia with EC(50) values of 17.54 μg/ml and highly inhibited the growth of a variety of bacteria, while the synthetic EP-20 peptide was highly active against Phytophthora capsici with EC(50) values of 3.14 μg/ml.
authors.affiliation: Key Laboratory of Integrated Pest Management in Crop, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Science, Beijing, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Xiao
authors.forename: Fanlu
authors.initials: F
authors.lastname: Meng
authors.forename: Dewen
authors.initials: D
authors.lastname: Qiu
authors.forename: Xiufen
authors.initials: X
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001407:Bacillus / Q000187:drug effects; D001419:Bacteria / Q000187:drug effects*; D005658:Fungi / Q000187:drug effects*; D005670:Fusarium / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D010838:Phytophthora / Q000187:drug effects; D011525:Prototheca / Q000187:drug effects; D043368:Ralstonia solanacearum / Q000187:drug effects; D020539:Sequence Analysis, Protein; D020172:Verticillium / Q000187:drug effects; D020593:Xenorhabdus / Q000378:metabolism*
chemical_list: D000890:Anti-Infective Agents; D023181:Antimicrobial Cationic Peptides