title: A synthetic peptide containing a predominant protein kinase C site within p47phox inhibits the NADPH oxidase in intact neutrophils.
abstract: In vivo loading of a synthetic peptide (peptide 4) corresponding to residues 314-331 (RSRKRLSQDAYRRNSVRF) consistently diminished the oxidative burst in response to either phorbol 12-myristate 13-acetate (PMA) or formylmethionyl-leucyl-phenylalanine and cytochalasin B (fMLP/CB) compared to other synthetic peptides derived from the p47phox sequence. The effects of peptide 4 were concentration dependent with respect to both PMA and fMLP/CB. In contrast, peptide 4 enhanced the oxidative burst in response to fMLP alone. Peptide 4 inhibited the PMA and fMLP-mediated phosphorylation of endogenous neutrophil cytosolic proteins including p47phox. The PMA-induced translocation of p47phox to the plasma membrane was diminished in neutrophils loaded with peptide 4. These data represent the first report of a synthetic peptide derived from p47phox that inhibits the NADPH oxidase in intact neutrophils and inhibits the protein kinase C-mediated phosphorylation of endogenous p47phox.
authors.affiliation: Department of Pathology, University of Connecticut Health Center, Farmington 06030-3105, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Labadia
authors.forename: Y L
authors.initials: YL
authors.lastname: Zu
authors.forename: C K
authors.initials: CK
authors.lastname: Huang
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D003571:Cytochalasin B / Q000037:antagonists & inhibitors / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000378:metabolism* / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors* / Q000097:blood; D009252:NADPH Dehydrogenase / Q000378:metabolism* / Q000494:pharmacology*; D019255:NADPH Oxidases; D009504:Neutrophils / Q000187:drug effects* / Q000201:enzymology*; D010446:Peptide Fragments / Q000494:pharmacology*; D010750:Phosphoproteins / Q000378:metabolism* / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism*; D016897:Respiratory Burst / Q000187:drug effects / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000037:antagonists & inhibitors / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D010446:Peptide Fragments; D010750:Phosphoproteins; D003571:Cytochalasin B; D009240:N-Formylmethionine Leucyl-Phenylalanine; D009247:NADH, NADPH Oxidoreductases; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D009252:NADPH Dehydrogenase; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate