title: Nox2 B-loop peptide, Nox2ds, specifically inhibits the NADPH oxidase Nox2.
abstract: In recent years, reactive oxygen species (ROS) derived from the vascular isoforms of NADPH oxidase, Nox1, Nox2, and Nox4, have been implicated in many cardiovascular pathologies. As a result, the selective inhibition of these isoforms is an area of intense current investigation. In this study, we postulated that Nox2ds, a peptidic inhibitor that mimics a sequence in the cytosolic B-loop of Nox2, would inhibit ROS production by the Nox2-, but not the Nox1- and Nox4-oxidase systems. To test our hypothesis, the inhibitory activity of Nox2ds was assessed in cell-free assays using reconstituted systems expressing the Nox2-, canonical or hybrid Nox1-, or Nox4-oxidase. Our findings demonstrate that Nox2ds, but not its scrambled control, potently inhibited superoxide (O(2)(•-)) production in the Nox2 cell-free system, as assessed by the cytochrome c assay. Electron paramagnetic resonance confirmed that Nox2ds inhibits O(2)(•-) production by Nox2 oxidase. In contrast, Nox2ds did not inhibit ROS production by either Nox1- or Nox4-oxidase. These findings demonstrate that Nox2ds is a selective inhibitor of Nox2-oxidase and support its utility to elucidate the role of Nox2 in organ pathophysiology and its potential as a therapeutic agent.
authors.affiliation: Vascular Medicine Institute, Department of Pharmacology & Chemical Biology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
authors.forename: Gábor
authors.initials: G
authors.lastname: Csányi
authors.forename: Eugenia
authors.initials: E
authors.lastname: Cifuentes-Pagano
authors.forename: Imad
authors.initials: I
authors.lastname: Al Ghouleh
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Ranayhossaini
authors.forename: Loreto
authors.initials: L
authors.lastname: Egaña
authors.forename: Lucia R
authors.initials: LR
authors.lastname: Lopes
authors.forename: Heather M
authors.initials: HM
authors.lastname: Jackson
authors.forename: Eric E
authors.initials: EE
authors.lastname: Kelley
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Pagano
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology; D040761:Biomimetic Materials / Q000494:pharmacology; D019556:COS Cells; D002522:Chlorocebus aethiops; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D015202:Protein Engineering; D017382:Reactive Oxygen Species / Q000378:metabolism; D013481:Superoxides / Q000378:metabolism
chemical_list: D000975:Antioxidants; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D017382:Reactive Oxygen Species; D013481:Superoxides; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases