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Fungal defensin antimicrobial peptide

Plectasin

Plectasin is a 40-amino-acid antimicrobial peptide from the saprophytic fungus Pseudoplectania nigrella, and the first defensin discovered in a fungus.

By The Peptides Codex Editorial TeamIndividual review date not recorded

Page data last changed: . Registry refreshes and identity assessments are separate from scientific content review.

Length
40 aa
Class
Fungal defensin antimicrobial peptide
Function
Lipid II-binding inhibitor of bacterial cell-wall synthesis
Context
Research antimicrobial studied against Gram-positive pathogens

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.

Structure & chemistry

Molecular identity & reference confidence

Reference mass unavailable

Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.

Molecular form
Plectasin (source record; form not independently established)
Species
Not established by this molecular identity audit
Termini (N / C)
Not specified / Not specified

Average reference mass

Reference policy updated: 2026-10-05

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.

What Canadian product status is recorded for Plectasin?+

Canadian product status for Plectasin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.

What is the typical length of Plectasin?+

Plectasin is commonly described as approximately 40 amino acids (Fungal defensin antimicrobial peptide).

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References & further reading

  1. 1.Derks et al. (2026). Molecular action of NZ2114, a superior plectasin derivative. NPJ Antimicrob Resist
  2. 2.Davids et al. (2025). Antimycobacterial activity of the plectasin derivative NZ2114. Front Microbiol
  3. 3.Ma et al. (2024). Polylactic Glycolic Acid-Mediated Delivery of Plectasin Derivative NZ2114 in Staphylococcus epidermidis Biofilms. Antibiotics (Basel)
  4. 4.Breidenstein et al. (2015). Antimicrobial Activity of Plectasin NZ2114 in Combination with Cell Wall Targeting Antibiotics Against VanA-Type Enterococcus faecalis. Microb Drug Resist
  5. 5.Hu et al. (2015). Combinations of β-lactam or aminoglycoside antibiotics with plectasin are synergistic against methicillin-sensitive and methicillin-resistant Staphylococcus aureus. PLoS One
  6. 6.Lima et al. (2017). Fusion of plectasin derivative NZ2114 with hydrophilic random coil polypeptide: Recombinant production in Pichia pastoris and antimicrobial activity against clinical strain MRSA. Biopolymers
  7. 7.Andes et al. (2009). In vivo pharmacodynamic characterization of a novel plectasin antibiotic, NZ2114, in a murine infection model. Antimicrob Agents Chemother
  8. 8.Klein et al. (2017). Controlled Release of Plectasin NZ2114 from a Hybrid Silicone-Hydrogel Material for Inhibition of Staphylococcus aureus Biofilm. Antimicrob Agents Chemother
  9. 9.PubMed — Plectasin is a peptide antibiotic with therapeutic potential from a saprophytic fungus (Nature 2005)
  10. 10.Wikipedia — Plectasin
Disclaimer: Educational content only. Not medical advice. Not instructions for human use. Research peptides and unapproved products may be restricted or illegal to market for human consumption in your jurisdiction. Consult qualified professionals and applicable law.
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