Artículo
Insights into the mechanism of the reaction between hydrogen sulfide and peroxynitrite
Cuevasanta, Ernesto; Zeida Camacho, Ari Fernando
; Carballal, Sebastián; Wedmann, Rudolf; Morzan, Uriel N.; Trujillo, Madia; Radi, Rafael; Estrin, Dario Ariel
; Filipovic, Milos R.; Alvarez, Beatriz
![Icon](/themes/CONICETDigital/images/conicet.png)
![Icon](/themes/CONICETDigital/images/conicet.png)
Fecha de publicación:
01/2015
Editorial:
Elsevier Science Inc
Revista:
Free Radical Biology and Medicine
ISSN:
0891-5849
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Hydrogen sulfide and peroxynitrite are endogenously generated molecules that participate in biologically relevant pathways. A revision of the kinetic features of the reaction between peroxynitrite and hydrogen sulfide revealed a complex process. The rate constant of peroxynitrite decay, (6.65 ± 0.08) × 103 M-1 s-1 in 0.05 M sodium phosphate buffer (pH 7.4, 37 °C), was affected by the concentration of buffer. Theoretical modeling suggested that, as in the case of thiols, the reaction is initiated by the nucleophilic attack of HS- on the peroxide group of ONOOH by a typical bimolecular nucleophilic substitution, yielding HSOH and NO2 -. In contrast to thiols, the reaction then proceeds to the formation of distinct products that absorb near 408 nm. Experiments in the presence of scavengers and carbon dioxide showed that free radicals are unlikely to be involved in the formation of these products. The results are consistent with product formation involving the reactive intermediate HSSH and its fast reaction with a second peroxynitrite molecule. Mass spectrometry and UV-Vis absorption spectra predictions suggest that at least one of the products is HSNO2 or its isomer HSONO.
Palabras clave:
Hydrogen Sulfide
,
Peroxynitrite
,
Kinetics
,
Oxidation
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Articulos(INQUIMAE)
Articulos de INST.D/QUIM FIS D/L MATERIALES MEDIOAMB Y ENERGIA
Articulos de INST.D/QUIM FIS D/L MATERIALES MEDIOAMB Y ENERGIA
Citación
Cuevasanta, Ernesto; Zeida Camacho, Ari Fernando; Carballal, Sebastián; Wedmann, Rudolf; Morzan, Uriel N.; et al.; Insights into the mechanism of the reaction between hydrogen sulfide and peroxynitrite; Elsevier Science Inc; Free Radical Biology and Medicine; 80; 1-2015; 93-100
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