Elafin (elastase-specific inhibitor) has anti-microbial activity against gram-positive and gram-negative respiratory pathogens

FEBS Lett. 1999 Jun 11;452(3):309-13. doi: 10.1016/s0014-5793(99)00670-5.


Elafin (elastase-specific inhibitor) is a low molecular weight inhibitor of neutrophil elastase which is secreted in the lung. Using synthetic peptides corresponding to full-length elafin (H2N-1AVT.....95Q-OH), the NH2-terminal domain (H2N-1AVT.....50K-OH) and the COOH-terminal domain (H2N-51PGS.....95Q-OH), we demonstrate that elafin's anti-elastase activity resides exclusively in the COOH-terminus. Several characteristics of elafin suggest potential anti-microbial activity. The anti-microbial activity of elafin, and of its two structural domains, was tested against the respiratory pathogens Pseudomonas aeruginosa and Staphylococcus aureus. Elafin killed both bacteria efficiently, with 93% killing of P. aeruginosa by 2.5 microM elafin and 48% killing of S. aureus by 25 microM elafin. For both organisms, full-length elafin was required to optimise bacterial killing. These findings represent the first demonstration of co-existent anti-proteolytic and anti-microbial functions for elafin.

MeSH terms

  • Antifungal Agents / pharmacology*
  • Gram-Negative Bacteria / drug effects
  • Gram-Negative Bacteria / isolation & purification
  • Gram-Positive Bacteria / drug effects
  • Gram-Positive Bacteria / isolation & purification
  • Humans
  • Kinetics
  • Microbial Sensitivity Tests
  • Pancreatic Elastase / antagonists & inhibitors
  • Peptide Fragments / pharmacology
  • Proteinase Inhibitory Proteins, Secretory
  • Proteins / pharmacology*
  • Pseudomonas Infections / microbiology
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / isolation & purification
  • Respiratory Tract Infections / microbiology*
  • Serine Proteinase Inhibitors / pharmacology
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / drug effects*
  • Staphylococcus aureus / isolation & purification


  • Antifungal Agents
  • Peptide Fragments
  • Proteinase Inhibitory Proteins, Secretory
  • Proteins
  • Serine Proteinase Inhibitors
  • Pancreatic Elastase