Peroxynitrite

Federal government websites often end in. The site is secure, peroxynitrite.

Peroxynitrite can be prepared by the reaction of superoxide with nitric oxide : [1] [2] [3]. It is prepared by the reaction of hydrogen peroxide with nitrite : [4]. It is reactive toward DNA and proteins. It is these radicals carbonate radical and nitrogen dioxide that are believed to cause peroxynitrite-related cellular damage. Its conjugate acid peroxynitrous acid is highly reactive, although peroxynitrite is stable in basic solutions.

Peroxynitrite

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Massari J. Federal government websites often end in. Mn-SOD and hemeproteins or metal complexes e, peroxynitrite.

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In this review we provide an analysis of the biochemistry of peroxynitrite and tyrosine nitration. In addition, peroxynitrite anion can secondarily evolve to secondary radicals either via its fast reaction with CO 2 or through proton-catalyzed homolysis. Peroxynitrite can cause protein tyrosine nitration in vitro and in vivo. Protein tyrosine nitration can mediate changes in protein structure and function that affect cell homeostasis. Recently, mechanisms responsible of tyrosine nitration in hydrophobic biostructures such as membranes and lipoproteins have been assessed and involve the parallel occurrence and connection with lipid peroxidation. Experimental strategies to reveal the proximal oxidizing mechanism during tyrosine nitration in given pathophysiologically-relevant conditions include mapping and identification of the tyrosine nitration sites in specific proteins. Keywords: Free radicals; Nitric oxide; Oxidants; Peroxynitrite and tyrosine nitration. Published by Elsevier B. All rights reserved. Abstract In this review we provide an analysis of the biochemistry of peroxynitrite and tyrosine nitration.

Peroxynitrite

Federal government websites often end in. The site is secure. Peroxynitrite is the product of the diffusion-controlled reaction of nitric oxide and superoxide radicals. Peroxynitrite, a reactive short-lived peroxide with a p K a of 6. It also yields secondary free radical intermediates such as nitrogen dioxide and carbonate radicals.

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Through the reactions shown in Equations 14 — 16 , MnP can catalytically decompose peroxynitrite via a redox cycle of peroxynitrite reduction at the expense of endogenous reducing equivalents. The complete catalytic cycle to restore peroxiredoxin to the resting state is analyzed elsewhere The nucleophilic addition of peroxynitrite anion to monocarbonyl- and dicarbonyl-containing compounds e. This was the first determination of a second-order rate constant of peroxynitrite reaction with a biomolecule. It is important to note that, during vascular inflammation, neutrophil degranulation of myeloperoxidase also contributes to protein tyrosine nitration processes by peroxynitrite-independent mechanisms 51 , A highly abundant plasma protein, it consumes a fraction of intravascular peroxynitrite but cannot outcompete the reaction with CO 2. The direct reaction of peroxynitrite with uric acid is rather slow to account for its protective effects Table 1 ; thus, much of its effects may instead be due to the scavenging of peroxynitrite-derived radicals and the inhibition of tyrosine nitration reactions. Fridovich I. Mn-porphyrins MnP. Some answers to the cardinal questions in nitric oxide biology. Pacher P. J Biol Chem.

Federal government websites often end in. The site is secure. General Flores , Montevideo , Uruguay.

Science , — [ PubMed ] [ Google Scholar ]. The nucleophilic addition of peroxynitrite anion to monocarbonyl- and dicarbonyl-containing compounds e. It is relevant for peroxynitrite detoxification in red blood cells. Interactive image. Not only is nitro-Mn-SOD a footprint of the process, but also its inactivation by nitration contributes to further amplify mitochondrial nitroxidative stress The cytotoxic effects triggered by oxidation and nitration reactions usually involve the participation of a variety of effector molecules and processes. Oxidation and disruption of the iron-sulfur cluster 57 , S; Koppenol, W. Winterbourn C. Romero N. Alternative approaches have been also used, with the application of competition kinetics with reference reactions of known rate constants Isomerization to nitrate and secondary formation of protein radicals. This reaction was later shown in mammalian peroxiredoxin systems PMID Blough N.