Involvement of peroxynitrite (ONOO-) in inflammatory diseases has been implicated by detection of 3-nitrotyrosine, an allegedly characteristic protein oxidation product, in various inflamed tissues. We show here that nitrite (NO2-), the primary metabolic end product of nitric oxide (NO.), can be oxidized by the heme peroxidases horseradish peroxidase, myeloperoxidase (MPO), and lactoperoxidase ...

The relationship of peroxidases to an inducible disease-resistance mechanism involving lignification of leaf epidermal cell walls was studied. Reed canarygrass (Phalaris arundinacea L.) leaf discs were inoculated with Helminthosporium avenae Eidam and floated on water. In inoculated discs, the activity of soluble, ionic wall-bound and covalent wall-bound peroxidases was about twice the level of...

Introduction Peroxidases are common oxidoreductases present in plants, animals and micro-organisms. Plant peroxidases are classified as basic, neutral or acidic enzymes, depending on their profiles of elution during ion-exchange column chromatography or isoelectric points [ 11. Horseradish (Amtoru~h rusticuna) peroxidases (HRPs; EC 1.1 1.1.7), are probably the best characterized of these enzyme...

Plant peroxidases are involved in numerous cellular processes in plant development and stress responses. Four plasma membrane-bound peroxidases have been identified and characterized in maize (Zea mays L.) roots. In the present study, maize seedlings were treated with different stresses and signal compounds, and a functional analysis of these membrane-bound class III peroxidases (pmPOX1, pmPOX2...

Self-, cross- and non-pollinated styles of Petunia hybrida were treated with 3-3'-diaminobenzidine for the ultrastructural localization of peroxidase activity. Wall peroxidases were absent in cross-pollinated styles, but they were detectable as an osmiophilic deposit on the cell walls of the outer portion of the transmitting tissue in self- and non-pollinated styles. The cell layer showing pero...

Notomastus lobatus chloroperoxidase (NCPO) and Amphitrite ornata dehaloperoxidase (DHP) catalyze the halogenation of phenols and dehalogenation of halophenols, respectively. Both enzymes require peroxide for activity and have recently been shown to contain histidine (His) as their proximal heme iron ligand. DHP is the only heme enzyme known to catalyze peroxide-dependent defluorination reaction...