title: Prediction of antibacterial activity from physicochemical properties of antimicrobial peptides.
abstract: Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM), which conciliates the two types of observations.
authors.affiliation: Institute of Molecular Medicine, University of Lisbon, Lisbon, Portugal. m.n.melo@rug.nl
authors.forename: Manuel N
authors.initials: MN
authors.lastname: Melo
authors.forename: Rafael
authors.initials: R
authors.lastname: Ferre
authors.forename: Lídia
authors.initials: L
authors.lastname: Feliu
authors.forename: Eduard
authors.initials: E
authors.lastname: Bardají
authors.forename: Marta
authors.initials: M
authors.lastname: Planas
authors.forename: Miguel A R B
authors.initials: MA
authors.lastname: Castanho
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry* / Q000494:pharmacology*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D006090:Gram-Negative Bacteria / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D008954:Models, Biological; D009842:Oligopeptides / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D009842:Oligopeptides; C540525:lysyl-lysyl-leucyl-phenylalanyl-lysyl-lysyl-isoleucyl-leucyl-lysyl-tyrosyl-leucinamide; C478918:omiganan pentahydrochloride