Identification of novel bioactive hexapeptides against phytopathogenic bacteria through rapid screening of a synthetic combinatorial library.
Antimicrobial peptides (AMPs) are considered to be a promising alternative to conventional antibiotics for future generations. We identified four novel hexapeptides with antimicrobial activity: KCM11 (TWWRWW-NH(2)), KCM12 (KWRWIW-NH(2)), KCM21 (KWWWRW-NH(2)), and KRS22 (WRWFIH-NH(2)), through positional scanning of a synthetic peptide combinatorial library (PS-SCL). The ability of these peptides to inhibit the growth of a variety of bacteria and unicellular fungi was evaluated. KCM11 and KRS22 preferentially inhibited the normal growth of fungal strains, whereas KCM12 and KCM21 were more active against bacterial strains. Bactericidal activity was addressed in a clear zone assay against phytopathogenic bacteria, including Pectobacterium spp., Xanthomonas spp., Pseudomonas spp., etc. KCM21 showed the highest activity and was effective against a wide range of target organisms. Application of KCM21 with inoculation of Pectobacterium carotovorum subsp. carotovorum on detached cabbage leaves resulted in an immune phenotype or a significant reduction in symptom development, depending on the peptide concentration. Cytotoxicity of the four hexapeptides was evaluated in mouse and human epithelial cell lines using an MTT test. The results revealed a lack of cytotoxic effects.
Choi
Jaehyuk
J
Department of Molecular Science and Technology, Ajou University, Suwon 442-749, Korea.
Moon
Eunpyo
E
D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage* / Q000009:adverse effects / Q000138:chemical synthesis; D029741:Brassica rapa / Q000187:drug effects / Q000382:microbiology; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D016905:Gram-Negative Bacterial Infections / Q000188:drug therapy; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D044043:Pectobacterium / Q000187:drug effects; D019151:Peptide Library; D010935:Plant Diseases / Q000382:microbiology*; D011549:Pseudomonas / Q000187:drug effects; D014974:Xanthomonas / Q000187:drug effects
D023181:Antimicrobial Cationic Peptides; D019151:Peptide Library