title: Modulation of the activity of the NADPH oxidase system by reactive oxygen species: influence of catalase.
abstract: The nicotinamide adenine dinucleotide phosphate oxidase complex (Nox) is a major source of non-mitochondrial reactive oxygen species in cells. Nox contains both membrane (Cytb(558)) and cytosolic (p40(phox), p47(phox), p67(phox) and Rac) components. Nox has been submitted to a combination of oxygen free radicals produced by irradiation and to hydrogen peroxide. Irradiation of a single component with high doses led to partial inactivation; however, the irradiation of the whole system during its assembly phase with lower doses (2-10 Gy) led either to activation (2.7 Gy) or to strong inactivation if irradiation took place during the first minute of the assembly. Incubation of the membrane fractions or of p67(phox) with H(2)O(2) led to fast inactivation. Catalase protected weakly p67(phox) from H(2)O(2). Conversely, incubation of the membrane fractions with catalase led to over-activation of the system.
authors.affiliation: Laboratoire de Chimie Physique, UMR8000, Université Paris-Sud 11, Bât 350, F-91405 Orsay, France. mariano.ostuni@upmc.fr
authors.forename: Mariano A
authors.initials: MA
authors.lastname: Ostuni
authors.forename: Tania
authors.initials: T
authors.lastname: Bizouarn
authors.forename: Laura
authors.initials: L
authors.lastname: Baciou
authors.forename: Chantal
authors.initials: C
authors.lastname: Houée-Levin
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism*; D002474:Cell-Free System; D004789:Enzyme Activation; D004795:Enzyme Stability; D009249:NADP / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D009249:NADP; D002374:Catalase