Nitrite reduction mediated by heme models. Routes to NO and HNO?

The water-soluble ferriheme model Fe III (TPPS) mediates oxygen atom transfer from inorganic nitrite to a water-soluble phosphine (tppts), dimethyl sulfide, and the biological thiols cysteine (CysSH) and glutathione (GSH). The products with the latter reductant are the respective sulfenic acids CysS...

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Guardado en:
Detalles Bibliográficos
Autores principales: Suarez, Sebastian, Doctorovich, Fabio Ariel
Publicado: 2013
Materias:
Biological thiols
Dimethyl sulfide
Ischemia/reperfusion
Nitrite reduction
Oxygen atom transfer
Potential mechanism
Reactive intermediate
Redox transformations
Amino acids
Iron compounds
Linear transformations
Phosphorus compounds
Reduction
cysteine
dimethyl sulfide
glutathione
hematin
heme
nitric acid
nitric oxide
nitrite
oxygen
phosphine
sulfenic acid derivative
thiol
aqueous solution
article
electrochemistry
ischemia
nitrosylation
oxidation reduction reaction
reperfusion injury
Hemeproteins
Nitric Oxide
Nitrites
Nitrogen Oxides
Oxidation-Reduction
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00027863_v135_n10_p4007_Heinecke
http://hdl.handle.net/20.500.12110/paper_00027863_v135_n10_p4007_Heinecke
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
Descripción
Sumario:The water-soluble ferriheme model Fe III (TPPS) mediates oxygen atom transfer from inorganic nitrite to a water-soluble phosphine (tppts), dimethyl sulfide, and the biological thiols cysteine (CysSH) and glutathione (GSH). The products with the latter reductant are the respective sulfenic acids CysS(O)H and GS(O)H, although these reactive intermediates are rapidly trapped by reaction with excess thiol. The nitrosyl complex Fe II (TPPS)(NO) is the dominant iron species while excess substrate is present. However, in slightly acidic media (pH ≈ 6), the system does not terminate at this very stable ferrous nitrosyl. Instead, it displays a matrix of redox transformations linking spontaneous regeneration of Fe III (TPPS) to the formation of both N 2 O and NO. Electrochemical sensor and trapping experiments demonstrate that HNO (nitroxyl) is formed, at least when tppts is the reductant. HNO is the likely predecessor of the N 2 O. A key pathway to NO formation is nitrite reduction by Fe II (TPPS), and the kinetics of this iron-mediated transformation are described. Given that inorganic nitrite has protective roles during ischemia/reperfusion (I/R) injury to organs, attributed in part to NO formation, and that HNO may also reduce net damage from I/R, the present studies are relevant to potential mechanisms of such nitrite protection. © 2013 American Chemical Society.

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