Elafin: an elastase-specific inhibitor of human skin. Purification, characterization, and complete amino acid sequence

J Biol Chem. 1990 Sep 5;265(25):14791-5.


A potent inhibitor of human leukocyte elastase (EC and porcine pancreatic elastase (EC was purified to homogeneity from human horny layers. It inhibits human leukocyte elastase and porcine pancreatic elastase in a 1:1 molar ratio and shows equilibrium dissociation constants of 6 x 10(-10) M and 1 x 10(-9) M, respectively. Inhibition of plasmin, trypsin, alpha-chymotrypsin, and cathepsin G was not observed. This inhibitor proved to be an acid stable basic peptide with an isoelectric point of 9.7. The complete amino acid sequence appears to be unique with 38% homology to the C-terminal half of antileukoprotease. The sequence shows that the inhibitor is composed of 57 amino acids and predicts a Mr of 7017. The high affinity as well as the apparent specificity for elastases suggests a functional role in preventing elastase-mediated tissue proteolysis. It is suggested that the term "elafin" be used to designate this inhibitor.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Chromatography, Gel
  • Electrophoresis, Polyacrylamide Gel
  • Humans
  • Leukocytes / enzymology
  • Molecular Sequence Data
  • Molecular Weight
  • Pancreatic Elastase / antagonists & inhibitors*
  • Pancreatic Elastase / blood
  • Proteinase Inhibitory Proteins, Secretory
  • Proteins*
  • Sequence Homology, Nucleic Acid
  • Serine Proteinase Inhibitors / genetics
  • Serine Proteinase Inhibitors / isolation & purification*
  • Serine Proteinase Inhibitors / pharmacology
  • Skin / metabolism*


  • Proteinase Inhibitory Proteins, Secretory
  • Proteins
  • Serine Proteinase Inhibitors
  • Pancreatic Elastase