title: Interaction of a novel antimicrobial peptide isolated from the venom of solitary bee Colletes daviesanus with phospholipid vesicles and Escherichia coli cells.
abstract: The peptide named codesane (COD), consisting of 18 amino acid residues and isolated from the venom of wild bee Colletes daviesanus (Hymenoptera : Colletidae), falls into the category of cationic α-helical amphipathic antimicrobial peptides. In our investigations, synthetic COD exhibited antimicrobial activity against Gram-positive and Gram-negative bacteria and Candida albicans but also noticeable hemolytic activity. COD and its analogs (collectively referred to as CODs) were studied for the mechanism of their action. The interaction of CODs with liposomes led to significant leakage of calcein entrapped in bacterial membrane-mimicking large unilamellar vesicles made preferentially from anionic phospholipids while no calcein leakage was observed from zwitterionic liposomes mimicking membranes of erythrocytes. The preference of CODs for anionic phospholipids was also established by the blue shift in the tryptophan emission spectra maxima when the interactions of tryptophan-containing COD analogs with liposomes were examined. Those results were in agreement with the antimicrobial and hemolytic activities of CODs. Moreover, we found that the studied peptides permeated both the outer and inner cytoplasmic membranes of Escherichia coli. This was determined by measuring changes in the fluorescence of probe N-phenyl-1-naphthylamine and detecting cytoplasmic β-galactosidase released during the interaction of peptides with E. coli cells. Transmission electron microscopy revealed that treatment of E. coli with one of the COD analogs caused leakage of bacterial content mainly from the septal areas of the cells.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610, Prague 6, Czech Republic; Faculty of Science, Department of Biochemistry, Charles University in Prague, Hlavova 8, 12843, Prague 2, Czech Republic.
authors.forename: Sabína
authors.initials: S
authors.lastname: Čujová
authors.forename: Lucie
authors.initials: L
authors.lastname: Bednárová
authors.forename: Jiřina
authors.initials: J
authors.lastname: Slaninová
authors.forename: Jakub
authors.initials: J
authors.lastname: Straka
authors.forename: Václav
authors.initials: V
authors.lastname: Čeřovský
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000302:isolation & purification / Q000494:pharmacology*; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology*; D001514:Bee Venoms / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000494:pharmacology; D001516:Bees / Q000235:genetics; D002463:Cell Membrane Permeability / Q000187:drug effects; D015195:Drug Design; D004926:Escherichia coli / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D005453:Fluorescence; D006461:Hemolysis / Q000187:drug effects; D057927:Hydrophobic and Hydrophilic Interactions; D008081:Liposomes / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D010743:Phospholipids / Q000378:metabolism; D017433:Protein Structure, Secondary; D014364:Tryptophan / Q000737:chemistry
chemical_list: D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D001514:Bee Venoms; D008081:Liposomes; D010743:Phospholipids; C000598875:codesane peptide, Colletes daviesanus; D014364:Tryptophan
keywords: CD spectroscopy; antimicrobial peptides; electron microscopy; large unilamellar vesicles; membrane permeabilization; wild-bee venom