title: Anti-biofilm and sporicidal activity of peptides based on wheat puroindoline and barley hordoindoline proteins.
abstract: The broad-spectrum activity of antimicrobial peptides (AMPs) and low probability of development of host resistance make them excellent candidates as novel bio-control agents. A number of AMPs are found to be cationic, and a small proportion of these are tryptophan-rich. The puroindolines (PIN) are small, basic proteins found in wheat grains with proposed roles in biotic defence of seeds and seedlings. Synthetic peptides based on their unique tryptophan-rich domain (TRD) display antimicrobial properties. Bacterial endospores and biofilms are highly resistant cells, with significant implications in both medical and food industries. In this study, the cationic PIN TRD-based peptides PuroA (FPVTWRWWKWWKG-NH2 ) and Pina-M (FSVTWRWWKWWKG-NH2 ) and the related barley hordoindoline (HIN) based Hina (FPVTWRWWTWWKG-NH2 ) were tested for effects on planktonic cells and biofilms of the common human pathogens including Pseudomonas aeruginosa, Listeria monocytogenes and the non-pathogenic Listeria innocua. All peptides showed significant bactericidal activity. Further, PuroA and Pina-M at 2 × MIC prevented initial biomass attachment by 85-90% and inhibited >90% of 6-h preformed biofilms of all three organisms. However Hina, with a substitution of Lys-9 with uncharged Thr, particularly inhibited Listeria biofilms. The PIN based peptides were also tested against vegetative cells and endospores of Bacillus subtilis. The results provided evidence that these tryptophan-rich peptides could kill B. subtilis even in sporulated state, reducing the number of viable spores by 4 log units. The treated spores appeared withered under scanning electron microscopy. The results establish the potential of these tryptophan-rich peptides in controlling persistent pathogens of relevance to food industries and human health. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.
authors.affiliation: Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, John Street, Hawthorn, VIC, 3122, Australia.
authors.forename: Nadin
authors.initials: N
authors.lastname: Shagaghi
authors.affiliation: Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, John Street, Hawthorn, VIC, 3122, Australia.
authors.forename: Rebecca L
authors.initials: RL
authors.lastname: Alfred
authors.affiliation: Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, John Street, Hawthorn, VIC, 3122, Australia.
authors.forename: Andrew H A
authors.initials: AH
authors.lastname: Clayton
authors.affiliation: Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, John Street, Hawthorn, VIC, 3122, Australia.
authors.forename: Enzo A
authors.initials: EA
authors.lastname: Palombo
authors.affiliation: Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, John Street, Hawthorn, VIC, 3122, Australia.
authors.forename: Mrinal
authors.initials: M
authors.lastname: Bhave
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development / Q000648:ultrastructure; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D001467:Hordeum / Q000737:chemistry / Q000276:immunology; D008087:Listeria / Q000187:drug effects / Q000254:growth & development; D008089:Listeria monocytogenes / Q000187:drug effects / Q000254:growth & development; D008826:Microbial Sensitivity Tests; D010933:Plankton / Q000187:drug effects / Q000254:growth & development; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development; D013171:Spores, Bacterial / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D014908:Triticum / Q000737:chemistry / Q000276:immunology; D014364:Tryptophan / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D010940:Plant Proteins; C445077:hordoindoline B protein, Hordeum vulgare; C082942:puroindoline protein, Triticum aestivum; D014364:Tryptophan
keywords: Trp-rich peptides; antimicrobial peptides; biofilms; hordoindolines; puroindolines; tryptophan