title: Antimicrobial properties of derivatives of the cationic tryptophan-rich hexapeptide PAF26.
abstract: Short antimicrobial peptides represent an alternative to fight pathogen infections. PAF26 is a hexapeptide identified previously by a combinatorial approach against the fungus Penicillium digitatum and shows antimicrobial properties towards certain phytopathogenic fungi. In this work, PAF26 was used as lead compound and its properties were compared with two series of derivatives, obtained by either systematic alanine substitution or N-terminal amino acid addition. The alanine scan approach underlined the optimized sequence of PAF26 in terms of potency and permeation capability, and also the higher contribution of the cationic residues to these properties. The N-terminal addition of amino acids resulted in new heptapeptides with variations in their antimicrobial characteristics, and very low cytolysis to human red blood cells. Positive (Arg or Lys) and aromatic (Phe or Trp) residue addition increased broad spectrum activity of PAF26. Noteworthy, addition of selected residues had specific effects on the properties of derivatives of PAF26.
authors.affiliation: Instituto de Agroquímica y Tecnología de Alimentos (IATA)-CSIC, Apartado de Correos 73, Burjassot, 46100 Valencia, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Muñoz
authors.forename: Belén
authors.initials: B
authors.lastname: López-García
authors.forename: Enrique
authors.initials: E
authors.lastname: Pérez-Payá
authors.forename: Jose F
authors.initials: JF
authors.lastname: Marcos
mesh_terms: D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000008:administration & dosage* / Q000737:chemistry*; D023181:Antimicrobial Cationic Peptides / Q000008:administration & dosage* / Q000737:chemistry*; D004305:Dose-Response Relationship, Drug; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000008:administration & dosage* / Q000737:chemistry*; D010407:Penicillium / Q000166:cytology* / Q000187:drug effects*; D014364:Tryptophan / Q000737:chemistry
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D009842:Oligopeptides; C459185:PAF26 peptide; D014364:Tryptophan