2mn5

Publication Abstract from PubMed

Fungi and bacteria compete with an arsenal of secreted molecules for their ecological niche. This repertoire represents a rich and inexhaustible source for antibiotics and fungicides. Antimicrobial peptides are an emerging class of fungal defense molecules that are promising candidates for pharmaceutical applications. Based on a co-cultivation system, we studied the interaction of the coprophilous basidiomycete Coprinopsis cinerea with different bacterial species and identified a novel defensin, copsin. The polypeptide was recombinantly produced in Pichia pastoris and the 3D structure was solved by NMR. The cysteine stabilized alpha/beta-fold with a unique disulfide connectivity and an N-terminal pyroglutamate rendered copsin extremely stable against high temperatures and protease digestion. Copsin was bactericidal against a diversity of Gram positive bacteria, including human pathogens such as Enterococcus faecium and Listeria monocytogenes. Characterization of the antibacterial activity revealed that copsin bound specifically to the peptidoglycan precursor lipid II and therefore interfered with the cell wall biosynthesis. In particular, and unlike lantibiotics and other defensins, the third position of the lipid II pentapeptide is essential for effective copsin binding. The unique structural properties of copsin make it a possible scaffold for new antibiotics.

Copsin, a novel peptide-based fungal antibiotic interfering with the peptidoglycan synthesis.,Essig A, Hofmann D, Munch D, Gayathri S, Kunzler M, Kallio PT, Sahl HG, Wider G, Schneider T, Aebi M J Biol Chem. 2014 Oct 23. pii: jbc.M114.599878. PMID:25342741^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.