title: Phylloseptins: a novel class of anti-bacterial and anti-protozoan peptides from the Phyllomedusa genus.
abstract: Six novel peptides called phylloseptins (PS-1, -2, -3, -4, -5, and -6) showing anti-bacterial (PS-1) and anti-protozoan (PS-4 and -5) activities were isolated from the skin secretion of the Brazilian tree-frogs, Phyllomedusa hypochondrialis and Phyllomedusa oreades. Phylloseptins have a primary structure consisting of 19-21 amino acid residues (1.7-2.1 kDa). They have common structural features, such as a highly conserved N-terminal region and C-terminal amidation. Phylloseptin-1 (FLSLIPHAINAVSAIAKHN-NH2) demonstrated a strong effect against gram-positive and gram-negative bacteria (MICs ranging from 3 to 7.9 microM), without showing significant hemolytic activity (<0.6% at the MIC range) towards mammalian cells. Atomic force microscopy experiments indicated that the bacteriolytic properties of these peptides might be related to their disruptive action on the cell membrane, characterized by a number of bubble-like formations, preceding every cell lysis. PS-4 and PS-5 showed anti-protozoan activity with IC50 at about 5 microM for Trypanosoma cruzi.
authors.affiliation: Laboratório de Espectrometria de Massa, EMBRAPA, Recursos Genéticos e Biotecnologia, Brasília 70770-900, Brazil.
authors.forename: José Roberto S A
authors.initials: JR
authors.lastname: Leite
authors.forename: Luciano P
authors.initials: LP
authors.lastname: Silva
authors.forename: Maria Izabel S
authors.initials: MI
authors.lastname: Rodrigues
authors.forename: Maura V
authors.initials: MV
authors.lastname: Prates
authors.forename: Guilherme D
authors.initials: GD
authors.lastname: Brand
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Lacava
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Azevedo
authors.forename: Anamélia L
authors.initials: AL
authors.lastname: Bocca
authors.forename: Sergio
authors.initials: S
authors.lastname: Albuquerque
authors.forename: Carlos
authors.initials: C
authors.lastname: Bloch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000302:isolation & purification / Q000494:pharmacology*; D000981:Antiprotozoal Agents / Q000302:isolation & purification / Q000494:pharmacology*; D001001:Anura; D001938:Brazil; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D018625:Microscopy, Atomic Force; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000302:isolation & purification / Q000494:pharmacology; D012867:Skin / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D000981:Antiprotozoal Agents; D010456:Peptides, Cyclic; C533251:phylloseptin-1, Phyllomedusa; C533252:phylloseptin-2, Phyllomedusa; C533253:phylloseptin-3, Phyllomedusa