title: Identification and characterization of an antibacterial peptide of the 26-kDa protease of Sarcophaga peregrina with antibacterial activity.
abstract: Previously, we purified a serine protease with a molecular mass of 26 kDa that exhibits potent antibacterial activity from a pupal extract of Sarcophaga peregrina (flesh fly). We divided this protease into 12 peptides and examined their antibacterial activity. A peptide corresponding to residues 155 to 174 (peptide 9) was found to exhibit antibacterial activity comparable to that of the 26-kDa protease. When Escherichia coli was treated with peptide 9, the permeability of both the outer and inner membranes increased, and substrates for beta-lactamase and beta-galactosidase entered the cells, but beta-galactosidase did not leak out of the cells under these conditions. It was suggested that residues 6 to 18 of peptide 9 form an amphiphilic alpha-helix under hydrophobic conditions with an N-terminal basic loop and then interact with acidic phospholipids in the bacterial membranes.
authors.affiliation: Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tsuji
authors.forename: T
authors.initials: T
authors.lastname: Aoyama
authors.forename: K
authors.initials: K
authors.lastname: Takeuchi
authors.lastname: Homma Ki
authors.forename: H
authors.initials: H
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Nakajima
authors.forename: I
authors.initials: I
authors.lastname: Shimada
authors.forename: S
authors.initials: S
authors.lastname: Natori
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D002942:Circular Dichroism; D004175:Diptera / Q000737:chemistry / Q000378:metabolism*; D010450:Endopeptidases / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D004926:Escherichia coli / Q000187:drug effects*; D005947:Glucose / Q000378:metabolism; D019476:Insect Proteins / Q000737:chemistry / Q000494:pharmacology*; D008081:Liposomes / Q000378:metabolism; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D019476:Insect Proteins; D008081:Liposomes; D010446:Peptide Fragments; D010450:Endopeptidases; C441464:Sarcophaga peregrina 26-kDa protease (155-174); D012697:Serine Endopeptidases; D005947:Glucose