The antimicrobial peptide parabutoporin competes with p47(phox) as a PKC-substrate and inhibits NADPH oxidase in human neutrophils

FEBS Lett. 2006 Nov 13;580(26):6206-10. doi: 10.1016/j.febslet.2006.10.024. Epub 2006 Oct 19.


We investigated parabutoporin (PP), an antimicrobial scorpion peptide, to understand its inhibition on NADPH oxidase in human PMN. We show that PP is a good substrate for all PKC-isotypes, implicated in the activation of NADPH oxidase, and acts as a potent competitive inhibitor of in vitro p47(phox)-phosphorylation by PKC-alpha, -betaI, -betaII and -delta, but not PKC-zeta. In PMN, PP also inhibits the PMA-stimulated phosphorylation of p47(phox) and its subsequent translocation. In contrast, PP affects the PKC-independent activation to a much lesser degree. This indicates that PP inhibits the activation of NADPH oxidase at submicromolar concentrations in a strongly PKC-dependent manner.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antimicrobial Cationic Peptides / metabolism
  • Antimicrobial Cationic Peptides / pharmacology*
  • Binding, Competitive
  • Humans
  • NADPH Oxidases / antagonists & inhibitors*
  • NADPH Oxidases / metabolism
  • Neutrophils / drug effects*
  • Phosphorylation
  • Protein Isoforms
  • Protein Kinase C / metabolism*
  • Scorpion Venoms / chemistry*
  • Scorpion Venoms / metabolism
  • Scorpion Venoms / pharmacology


  • Antimicrobial Cationic Peptides
  • Protein Isoforms
  • Scorpion Venoms
  • parabutoporin, Parabuthus schlechteri
  • NADPH Oxidases
  • neutrophil cytosolic factor 1
  • Protein Kinase C