A novel peptide-based antibiotic agent has been identified as naturally occurring in a common fungi, according to recent data.
Researchers at ETH Zurich examined the inky cap mushroom Coprinopsis cinerea to understand how the fungus interacts with bacteria. After cultivating the mushroom, which is found naturally growing within horse excrement, researchers determined its ability to kill bacteria is the result of a novel defensin, copsin.
Unlike most proteins, copsin remained stable when heated to 100 degrees Celsius or exposed to protein-degrading enzymes. It demonstrated antibiotic capabilities against several gram-positive bacteria, including Enterococcus faecium and Listeria monocytogenes. Through microscopy studies and binding assays with cell wall precursors, the researchers found that copsin acts by binding itself to the peptidoglycan precursor lipid II, interfering with the bacteria’s cell wall biosynthesis.
“Co-cultivation studies of C. cinerea with bacteria led to the identification of the peptide-based antibiotic copsin, to our knowledge the first defensin identified and characterized in the fungal phylum of basidiomycota,” the researchers wrote. “The exceptional stability of copsin and the potent activity against bacteria are important features for further applications in clinics or food industry.”
Disclosure: The researchers report no relevant financial disclosures.