Amino-terminal processing of chemokine ENA-78 regulates biological activity

Biochemistry. 1999 Jan 12;38(2):636-42. doi: 10.1021/bi981294s.


Epithelial cell-derived neutrophil-activating protein-78 (ENA-78) is a potent stimulator of neutrophils, inducing a variety of biological responses such as chemotaxis, enzyme release, up-regulation of surface receptors, and intracellular calcium mobilization. Proteolysis of ENA-78 with cathepsin G and chymotrypsin yielded a time-dependent increase in elastase-releasing activity, predicting the formation of truncation products with higher potency than native ENA-78. To investigate the biological implications of progressive truncation of ENA-78, the N-terminal variants ENA(5-78), ENA(9-78), and ENA(10-78) were cloned and expressed in E. coli. When tested in the neutrophil elastase release assay, the variants ENA(5-78) and ENA(9-78) had a 2-3-fold higher potency than full-length ENA-78, while ENA(10-78) was 3-fold less potent. In the chemotaxis assay, the variant ENA(5-78) exhibited an 8-fold and ENA(9-78) a 2-fold higher potency than native ENA-78. ENA(10-78), conversely, was 10-fold less potent, but reached a comparable efficacy to ENA-78 at 10(-)7 M concentration. In summary, the rank order in potency with respect to elastase release was ENA(9-78) > ENA(5-78) > ENA-78 > ENA(10-78), while for chemotaxis it was ENA(5-78) > ENA(9-78) > ENA-78 > ENA(10-78). Variant ENA(5-78) had a higher overall potency and efficiency for chemotaxis than interleukin-8 (IL-8), while ENA(9-78) exhibited a higher efficiency at concentrations of 1-100 nM. The fact that neutrophil cathepsin G produces the stable ENA(9-78) variant in vitro strongly suggests a role for this N-terminal proteolysis during inflammatory processes in vivo.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Calcium / metabolism
  • Chemokine CXCL5
  • Chemokines, CXC / blood
  • Chemokines, CXC / genetics
  • Chemokines, CXC / physiology
  • Chemotaxis, Leukocyte*
  • Cloning, Molecular
  • Cytosol / metabolism
  • Endopeptidases / metabolism
  • Humans
  • Hydrolysis
  • Interleukin-8 / analogs & derivatives*
  • Interleukin-8 / blood
  • Interleukin-8 / genetics
  • Interleukin-8 / physiology
  • Leukocyte Elastase / metabolism
  • Molecular Sequence Data
  • Mutagenesis, Insertional
  • Neutrophil Activation*
  • Neutrophils / enzymology
  • Neutrophils / physiology
  • Peptide Fragments / blood*
  • Peptide Fragments / genetics
  • Peptide Fragments / physiology
  • Protein Folding
  • Protein Processing, Post-Translational*
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / isolation & purification


  • CXCL5 protein, human
  • Chemokine CXCL5
  • Chemokines, CXC
  • Interleukin-8
  • Peptide Fragments
  • Recombinant Fusion Proteins
  • Endopeptidases
  • Leukocyte Elastase
  • Calcium