Lucimycin, an antifungal peptide from the therapeutic maggot of the common green bottle fly Lucilia sericata

We report the identification, cloning, heterologous expression and functional characterization of a novel antifungal peptide named lucimycin from the common green bottle fly Lucilia sericata. The lucimycin cDNA was isolated from a library of genes induced during the innate immune response in L. sericata larvae, which are used as therapeutic maggots. The peptide comprises 77 amino acid residues with a molecular mass of 8.2 kDa and a pI of 6.6. It is predicted to contain a zinc-binding motif and to form a random coil, lacking beta-sheets or other secondary structures. Lucimycin was active against fungi from the phyla Ascomycota, Basidiomycota and Zygomycota, in addition to the oomycete Phytophtora parasitica, but it was inactive against bacteria. A mutant version of lucimycin, lacking the four C-terminal amino acid residues, displayed 40-fold lower activity. The activity of lucimycin against a number of highly-destructive plant pathogens could be exploited to produce transgenic crops that are resistant against fungal diseases.