Cupiennin 1, a new family of highly basic antimicrobial peptides in the venom of the spider Cupiennius salei (Ctenidae).
A new family of antimicrobial peptides was isolated from the venom of Cupiennius salei. The peptides were purified to homogeneity, and the sequence of cupiennin 1a was determined by Edman degradation: GFGALFKFLAKKVAKTVAKQAAKQGAKYVVNKQME-NH(2). The amino acid sequences of cupiennin 1b, c, and d were obtained by a combination of sequence analysis and mass spectrometric measurements of comparative tryptic peptide mapping. All peptides consist of 35 amino acid residues and are characterized by a more hydrophobic N-terminal chain region and a C terminus composed preferentially of polar and charged residues. The total charge of all cupiennins calculated under physiological conditions is +8, and their C terminus, formed by a glutamic acid residue, is amidated. Conformational studies of the peptides revealed a high helix forming potential. Antimicrobial assays on bacteria with cupiennin 1a, 1d, and synthesized cupiennins 1a* and 1d* showed minimal inhibitory concentrations for bacteria in the submicromolar range. Their lytic effect on human red blood cells was lower by a factor of 8 to 14 than the highly hemolytic melittin. Cupiennin 1a, 1b, 1d, 1a*, and 1d* showed pronounced insecticidal activity. The immediate biological effects and the structural properties of the isolated cupiennins indicate a membrane-destroying mode of action on prokaryotic as well as eukaryotic cells.
Kuhn-Nentwig
Lucia
L
Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland. lucia.kuhn@zos.unibe.ch
Muller
Jurg
J
Schaller
Johann
J
Walz
Alfred
A
Dathe
Margitta
M
Nentwig
Wolfgang
W
D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D002942:Circular Dichroism; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis; D006801:Humans; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010455:Peptides; D017386:Sequence Homology, Amino Acid; D021241:Spectrometry, Mass, Electrospray Ionization; D013111:Spider Venoms / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D013112:Spiders
D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D010455:Peptides; D013111:Spider Venoms; C453880:cupiennin 1a