Researchers from Technical University Berlin and the Deinobiotics subsidiary of Deinove S.A. (Euronext:ALDEI) identified a new class of antimicrobials, a group of ribosomally synthesized peptides called lipolanthines, in a paper published Monday in Nature Chemical Biology.
Antimicrobial peptides are part of a new wave of therapeutic candidates to combat antibacterial resistance, and new screening platforms and synthetic approaches could finally help overcome their history of limited clinical efficacy, systemic toxicity and high cost (see "Peptides Step Up").
First, the team found evidence of antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA), S. pneumoniae and other Gram-positive bacteria in culture extracts of the actinomycete bacteria Microbacterium arborescens. The authors then isolated the bioactive compound, dubbed microvionin.
The researchers also isolated a second antimicrobial peptide, nocavionin, from another actinomycete, Nocardia altamirensis. Bacteria of the Actinomycetales order naturally occur in soil and are a source of antimicrobial compounds used to develop drugs.
Using structural and genomic analyses, the researchers found the compounds were produced via the biosynthetic pathways of ribosomal peptide synthesis and fatty acid or polyketide biosynthesis. As the biosynthetic pathways produced a unique peptide structure combining traits of lanthipeptides -- known ribosomally synthesized peptides with antimicrobial properties -- with fatty acid moieties, the authors named the new class lipolanthines.
The authors theorize that the microbials could function as inhibitors of cell wall biosynthesis. In the paper, the authors said they plan to further investigate the compounds' mechanism of action to develop them as antimicrobial drugs.