Oxidation of carbon monoxide by perferrylmyoglobin
| Autor: | Silvia H. Libardi, Daniel R. Cardoso, Leif H. Skibsted |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Carbon Monoxide
Aqueous solution Myoglobin Metabolite Radical Iron Tryptophan Electron Spin Resonance Spectroscopy General Chemistry Hydrogen-Ion Concentration Photochemistry Medicinal chemistry chemistry.chemical_compound Kinetics Reaction rate constant chemistry Animals Reactivity (chemistry) Horses General Agricultural and Biological Sciences Oxidation-Reduction Carbon monoxide |
| Zdroj: | Journal of agricultural and food chemistry. 62(8) |
| ISSN: | 1520-5118 |
| Popis: | Perferrylmyoglobin is found to oxidize CO in aerobic aqueous solution to CO2. Tryptophan hydroperoxide in the presence of tetra(4-sulfonatophenyl)-porphyrinate-iron(III) or simple iron(II)/(III) salts shows similar reactivity against CO. The oxidation of CO is for tryptophan hydroperoxide concluded to depend on the formation of alkoxyl radicals by reductive cleavage by iron(II) or on the formation of peroxyl radicals by oxidative cleavage by iron(III). During oxidation of CO, the tryptophan peroxyl radical was depleted with a rate constant of 0.26 ± 0.01 s(-1) for CO-saturated aqueous solution of pH 7.4 at 25 °C without concomitant reduction of the iron(IV) center. Carbon monoxide is as a natural metabolite accordingly capable of scavenging tryptophan radicals in myoglobin activated by peroxides with a second-order rate constant of (3.3 ± 0.6) × 10(2) L mol(-1) s(-1), a reaction that might be of importance in cellular membranes of the intestine for protection of tissue against radical damage during meat digestion. |
| Databáze: | OpenAIRE |
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