Antimicrobial peptides in insects; structure and function

• Published in: Developmental and comparative immunology 1999-06, Vol.23 (4-5), p.329-344
• Main Authors: Bulet, Phillipe, Hetru, Charles, Dimarcq, Jean-Luc, Hoffmann, Daniéle
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - metabolism; Anti-Bacterial Agents - pharmacology; Antimicrobial Cationic Peptides; antimicrobial peptides; Bacteria - drug effects; Defensins; Drosophila Proteins; Fungi - drug effects; Humans; Insect Proteins - chemistry; Insect Proteins - genetics; Insect Proteins - metabolism; Insect Proteins - pharmacology; Insect Proteins - physiology; Insecta; Insecta - immunology; Life Sciences; Molecular Sequence Data; Peptides, Cyclic - chemistry; Peptides, Cyclic - pharmacology; Protein Structure, Tertiary; Scorpions - chemistry; Scorpions - immunology; Sequence Alignment
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/S0145-305X(99)00015-4

Antimicrobial peptides appear to be ubiquitous and multipotent components of the innate immune defense arsenal used by both prokaryotic and eukaryotic organisms. During the past 15 years a multitude of these peptides have been isolated largely from insects. In spite of great differences in size, amino acid composition and structure, most of the antimicrobial peptides from insects can be grouped into one of three categories. The largest category in number contains peptides with intramolecular disulfide bonds forming hairpin-like β-sheets or α-helical–β-sheet mixed structures. The second most important group is composed of peptides forming amphipathic α-helices. The third group comprises peptides with an overrepresentation in proline and/or glycine residues. In general, the insect antimicrobial peptides have a broad range of activity and are not cytotoxic. Despite a wealth of information on structural requirements for their antimicrobial activity, the mode of action of these peptides is not yet fully understood. However, some data suggest the existence of two types of mode of action:1.through peptide–lipid interaction or2.through receptor-mediated recognition processes. This review presents the main results obtained during the last four years in the field of antimicrobial peptides from insects with a special focus on the proline-rich and cysteine-rich peptides.