A new active antimicrobial peptide from PD-L4, a type 1 ribosome inactivating protein of Phytolacca dioica L.: A new function of RIPs for plant defence?

FEBS Lett. 2015 Sep 14;589(19 Pt B):2812-8. doi: 10.1016/j.febslet.2015.08.018. Epub 2015 Aug 20.


We investigated the antimicrobial activity of PD-L4, a type 1 RIP from Phytolacca dioica. We found that this protein is active on different bacterial strains both in a native and denatured/alkylated form and that this biological activity is related to a cryptic peptide, named PDL440-65, identified by chemical fragmentation. This peptide showed the same antimicrobial activity of full-length protein and possessed, similarly to several antimicrobial peptides, an immunomodulatory effect on human cells. It assumes an alpha-helical conformation when interact with mimic membrane agents as TFE and likely bacterial membranes are a target of this peptide. To date PDL440-65 is the first antimicrobial peptide identified in a type 1 RIP.

Keywords: Antimicrobial peptide; Cationic antimicrobial peptide; Phytolacca dioica; Ribosome inactivating protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Anti-Infective Agents / toxicity
  • Bacteria / drug effects
  • Caco-2 Cells
  • Humans
  • Molecular Sequence Data
  • Peptide Fragments / chemistry
  • Peptide Fragments / pharmacology*
  • Peptide Fragments / toxicity
  • Phytolacca / chemistry
  • Phytolacca / physiology*
  • Plant Leaves / chemistry
  • Plant Proteins / chemistry
  • Plant Proteins / metabolism*
  • Protein Conformation
  • Ribosome Inactivating Proteins / chemistry
  • Ribosome Inactivating Proteins / metabolism*


  • Anti-Infective Agents
  • Peptide Fragments
  • Plant Proteins
  • Ribosome Inactivating Proteins