title: High-throughput generation of small antibacterial peptides with improved activity.
abstract: Cationic antimicrobial peptides are able to kill a broad variety of Gram-negative and Gram positive bacteria and thus are good candidates for a new generation of antibiotics to treat multidrug-resistant bacteria. Here we describe a high-throughput method to screen large numbers of peptides for improved antimicrobial activity. The method relies on peptide synthesis on a cellulose support and a Pseudomonas aeruginosa strain that constitutively expresses bacterial luciferase. A complete substitution library of 12-amino-acid peptides based on a linearized variant (RLARIVVIRVAR-NH(2)) of the bovine peptide bactenecin was screened and used to determine which substitutions at each position of the peptide chain improved activity. By combining the most favorable substitutions, we designed optimized 12-mer peptides showing broad spectrum activities with minimal inhibitory concentrations (MIC) as low as 0.5 microg/ml against Escherichia coli. Similarly, we generated an 8-mer substituted peptide that showed broad spectrum activity, with an MIC of 2 microg/ml, against E. coli and Staphylococcus aureus.
authors.affiliation: Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, V6T 1Z3, Canada.
authors.forename: Kai
authors.initials: K
authors.lastname: Hilpert
authors.forename: Rudolf
authors.initials: R
authors.lastname: Volkmer-Engert
authors.forename: Tess
authors.initials: T
authors.lastname: Walter
authors.forename: Robert E W
authors.initials: RE
authors.lastname: Hancock
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification*; D023181:Antimicrobial Cationic Peptides / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D001681:Biological Assay / Q000379:methods*; D018929:Cell Culture Techniques / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods*; D008969:Molecular Sequence Data; D019151:Peptide Library; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D019151:Peptide Library; D010456:Peptides, Cyclic; D011994:Recombinant Proteins; C056454:bactenecin