title: Characterization of unique amphipathic antimicrobial peptides from venom of the scorpion Pandinus imperator.
abstract: Two novel antimicrobial peptides have been identified and characterized from venom of the African scorpion Pandinus imperator. The peptides, designated pandinin 1 and 2, are alpha-helical polycationic peptides, with pandinin 1 belonging to the group of antibacterial peptides previously described from scorpions, frogs and insects, and pandinin 2 to the group of short magainin-type helical peptides from frogs. Both peptides demonstrated high antimicrobial activity against a range of Gram-positive bacteria (2.4-5.2 microM), but were less active against Gram-negative bacteria (2.4-38.2 microM), and only pandinin 2 affected the yeast Candida albicans. Pandinin 2 also demonstrated strong haemolytic activity (11.1-44.5 microM) against sheep erythrocytes, in contrast with pandinin 1, which was not haemolytic. CD studies and a high-resolution structure of pandinin 2 determined by NMR, showed that the two peptides are both essentially helical, but differ in their overall structure. Pandinin 2 is composed of a single alpha-helix with a predominantly hydrophobic N-terminal sequence, whereas pandinin 1 consists of two distinct alpha-helices separated by a coil region of higher flexibility. This is the first report of magainin-type polycationic antimicrobial peptides in scorpion venom. Their presence brings new insights into the mode of action of scorpion venom and also opens new avenues for the discovery of novel antibiotic molecules from arthropod venoms.
authors.affiliation: Suntory Institute for Bioorganic Research, Mishima-Gun, Shimamoto-Cho, Wakayamadai 1-1-1, Osaka 618-8503, Japan. corzo@sunbor.or.jp
authors.forename: G
authors.initials: G
authors.lastname: Corzo
authors.forename: P
authors.initials: P
authors.lastname: Escoubas
authors.forename: E
authors.initials: E
authors.lastname: Villegas
authors.forename: K J
authors.initials: KJ
authors.lastname: Barnham
authors.forename: W
authors.initials: W
authors.lastname: He
authors.forename: R S
authors.initials: RS
authors.lastname: Norton
authors.forename: T
authors.initials: T
authors.lastname: Nakajima
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects / Q000254:growth & development; D002942:Circular Dichroism; D004912:Erythrocytes / Q000187:drug effects; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000254:growth & development; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000254:growth & development; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D011487:Protein Conformation; D012604:Scorpion Venoms / Q000737:chemistry / Q000494:pharmacology*; D012605:Scorpions / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D029867:Xenopus Proteins; D014982:Xenopus laevis
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides; D010455:Peptides; D012604:Scorpion Venoms; D029867:Xenopus Proteins; C476119:pandinin 1; C476118:pandinin 2; C053300:magainin 1 peptide, Xenopus