Binding and action of cecropin and cecropin analogues: antibacterial peptides from insects

• Published in: Biochimica et biophysica acta Vol. 939; no. 2; pp. 260 - 266
• Main Authors: STEINER, J, ANDREU, D, MERRIFIELD, R. B
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier 07.04.1988; North-Holland
• Subjects: Animals; Antimicrobial Cationic Peptides; Artificial membranes and reconstituted systems; Bacillus megaterium - drug effects; Bacillus megaterium - metabolism; Bacteria - drug effects; Bacteria - metabolism; Biological and medical sciences; Cattle; Cell Membrane - drug effects; Cell Membrane - metabolism; Electrochemistry; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; Escherichia coli - drug effects; Escherichia coli - metabolism; Fundamental and applied biological sciences. Psychology; Hemolysis; Insect Hormones - metabolism; Insect Hormones - pharmacology; Kinetics; Lipid Bilayers - metabolism; Liposomes - metabolism; Membrane physicochemistry; Molecular biophysics; Protein Conformation; Pseudomonas aeruginosa - drug effects; Pseudomonas aeruginosa - metabolism; Sheep; Structure-Activity Relationship; Incorporation; Plasma membrane; Liposome; Molecular interaction; Artificial membrane; Antibacterial agent; Mechanism of action
• ISSN: 0006-3002; 1878-2434
• DOI: 10.1016/0005-2736(88)90069-7

The mechanism of action of cecropin was studied by using liposomes as a model system. The bilayer was efficiently destroyed if the liposome net charge was zero or negative. Cecropin analogues with an impaired N-terminal helix had reduced membrane disrupting abilities that correlate with their lower antibacterial activity. The reduced bactericidal activity of the analogues was rationalized in terms of reduced binding to bacteria. The stoichiometry of cecropin killing of bacteria suggests that amounts of cecropin sufficient to form a monolayer strongly modify the bacterial membrane. Although some bacteria were resistant to cecropin they did bind large amounts in a non-productive manner. In contrast, mammalian erythrocytes achieve resistance by avoiding the binding of cecropin.