title: Catalase catalyzes nitrotyrosine formation from sodium azide and hydrogen peroxide.
abstract: Sodium azide (NaN3) is known as an inhibitor of catalase, and a nitric oxide (NO) donor in the presence of catalase and H2O2. We showed here that catalase-catalyzed oxidation of NaN3 can generate reactive nitrogen species which contribute to tyrosine nitration in the presence of H2O2. The formation of free-tyrosine nitration and protein-bound tyrosine nitration by the NaN3/catalase/H2O2 system showed a maximum level at pH 6.0. Free-tyrosine nitration induced by peroxynitrite was inhibited by ethanol and dimethylsulfoxide (DMSO), and augmented by superoxide dismutase (SOD). However, free-tyrosine nitration induced by the NaN3/catalase/H2O2 system was not affected by ethanol, DMSO and SOD. NO2- and NO donating agents did not affect free-tyrosine nitration by the NaN3/catalase/H2O2 system. The reaction of NaN3 with hydroxyl radical generating system showed free-tyrosine nitration, but no formation of nitrite and nitrate. The generation of nitrite (NO2-) and nitrate (NO3-) by the NaN3/catalase/H2O2 system was maximal at pH 5.0. These results suggested that the oxidation of NaN3 by the catalase/H2O2 system generates unknown peroxynitrite-like reactive nitrogen intermediates, which contribute to tyrosine nitration.
authors.affiliation: Department of Environmental and Preventative Medicine, Graduate School of Medical Science, Kanazawa University, Japan. ogino@med.kanazawa-u.ac.jp
authors.forename: K
authors.initials: K
authors.lastname: Ogino
authors.forename: N
authors.initials: N
authors.lastname: Kodama
authors.forename: M
authors.initials: M
authors.lastname: Nakajima
authors.forename: A
authors.initials: A
authors.lastname: Yamada
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Nagase
authors.forename: D
authors.initials: D
authors.lastname: Sadamitsu
authors.forename: T
authors.initials: T
authors.lastname: Maekawa
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism*; D002384:Catalysis; D002417:Cattle; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008163:Luminescent Measurements; D009566:Nitrates / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism; D019810:Sodium Azide / Q000378:metabolism*; D013997:Time Factors; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism*
chemical_list: D009566:Nitrates; D009573:Nitrites; D012710:Serum Albumin, Bovine; C002744:3-nitrotyrosine; D014443:Tyrosine; D019810:Sodium Azide; D006861:Hydrogen Peroxide; D002374:Catalase