Canadian Forest Service Publications
Proteins: Novel antimicrobial anionic cecropins from the spruce budworm feature a poly-L-aspartic acid C-terminus, 2021, Maaroufi, H.; Potvin, M.; Cusson, M.; Levesque, R.-C., NRCAN, LFC, Laurentian Forestry Centre, Quebec (Quebec) n.26142 11p.
Issued by: Laurentian Forestry Centre
Catalog ID: 40418
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Cecropins form a family of amphipathic α-helical cationic peptides with broadspectrum antibacterial properties and potent anticancer activity. The emergence of bacteria and cancer cells showing resistance to cationic antimicrobial peptides (CAMPs) has fostered a search for new, more selective and more effective alternatives to CAMPs. With this goal in mind, we looked for cecropin homologs in the genome and transcriptome of the spruce budworm, Choristoneura fumiferana. Not only did we find paralogs of the conventional cationic cecropins (Cfcec+), our creening also led to the identification of previously uncharacterized anionic cecropins (Cfcec), featuring a poly-L-aspartic acid C-terminus. Comparative peptide analysis indicated that the C-terminal helix of Cfcec is amphipathic, unlike that of Cfcec+, which is hydrophobic. Interestingly, molecular dynamics simulations pointed to the lower conformational flexibility of Cfcec peptides, relative to that of Cfcec+. Phylogenetic analysis suggests that the evolution of distinct Cfcec+ and Cfcec peptides may have resulted from an ancient duplication event within the Lepidoptera. Finally, we found that both anionic and cationic cecropins contain a BH3-like motif (G- [KQR]-[HKQNR]-[IV]-[KQR]) that could interact with Bcl-2, a protein involved in apoptosis; this observation is congruent with previous reports indicating that cecropins induce apoptosis. Altogether, our observations suggest that cecropins may provide templates for the development of new anticancer drugs. We also estimated the antibacterial activity of Cfcec-2 and a ΔCfce-2 peptide as AMPs by testing directly their ability in inhibiting bacterial growth