The first defensin identified in a fungus, killing bacteria by sequestering the cell-wall precursor lipid II.
Also known as: NZ2114 (derivative)
Part of the Foundational & therapeutic peptides cluster
Overview
Plectasin is a 40-amino-acid antimicrobial peptide from the saprophytic fungus Pseudoplectania nigrella, and the first defensin discovered in a fungus. It kills Gram-positive bacteria, including antibiotic-resistant Streptococcus pneumoniae, by binding the cell-wall precursor lipid II rather than by lysing membranes, and it can be produced recombinantly at high yield. This page is educational and not medical advice.
Source & context
Biological / chemical source: Saprophytic fungus Pseudoplectania nigrella (black bulgar)
Primary research or clinical context: Research antimicrobial studied against Gram-positive pathogens
Structure and origin
Plectasin shares the cysteine-stabilized alpha-beta defensin fold seen in insect and mussel defensins, held together by three disulfide bonds. Described in 2005, it was the first such defensin found in a fungus and can be expressed recombinantly, an advantage for studying peptide antibiotics at scale.
Mechanism and derivatives
Rather than permeabilizing membranes, plectasin binds lipid II in a defined stoichiometric complex, blocking peptidoglycan assembly. Engineered variants such as NZ2114 were studied for improved potency against staphylococci and streptococci. Bacteria develop resistance slowly in preclinical work, sustaining research interest.
FAQ about Plectasin
What is Plectasin?+
Plectasin is a 40-amino-acid antimicrobial peptide from the saprophytic fungus Pseudoplectania nigrella, and the first defensin discovered in a fungus. It kills Gram-positive bacteria, including antibiotic-resistant Streptococcus pneumoniae, by binding the cell-wall precursor lipid II rather than by lysing membranes, and it can be produced recombinantly at high yield. This page is educational and not medical advice.
Is Plectasin an approved medicine?+
Plectasin is discussed here as a research / educational topic. Research antimicrobial studied against Gram-positive pathogens. This is not medical advice.
What is the typical length of Plectasin?+
Plectasin is commonly described as approximately 40 amino acids (Fungal defensin antimicrobial peptide).