Plectasin is a peptide antibiotic with therapeutic potential from a saprophytic fungus

摘要: Animals and higher plants express endogenous peptide antibiotics called defensins. These small cysteine-rich peptides are active against bacteria, fungi viruses. Here we describe plectasin-the first defensin to be isolated from a fungus, the saprophytic ascomycete Pseudoplectania nigrella. Plectasin has primary, secondary tertiary structures that closely resemble those of defensins found in spiders, scorpions, dragonflies mussels. Recombinant plectasin was produced at very high, commercially viable, yield purity. In vitro, recombinant especially Streptococcus pneumoniae, including strains resistant conventional antibiotics. showed extremely low toxicity mice, cured them experimental peritonitis pneumonia caused by S. pneumoniae as efficaciously vancomycin penicillin. findings identify novel source antimicrobial defensins, show therapeutic potential plectasin. They also suggest insects, molluscs arose common ancestral gene.