A possible role of the Na(+)/K(+)-ATPase for O(2) production from H(2)O(2)
| Autor: | Marie-Hélène Baron, Francine Bruston, Régis Calvayrac, Emile Petit, Evelyne Duval, Lydie Grajcar |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Sodium-Potassium-Exchanging ATPase
ATPase Inorganic chemistry Biophysics chemistry.chemical_element Spectrum Analysis Raman Biochemistry Medicinal chemistry Oxygen chemistry.chemical_compound Animals Na+/K+-ATPase Hydrogen peroxide Molecular Biology Heme biology Cell Biology Glutathione Hydrogen Peroxide Kinetics chemistry Catalase biology.protein Cattle |
| Zdroj: | Biochemical and biophysical research communications. 274(3) |
| ISSN: | 0006-291X |
| Popis: | We are attempting to supply a new insight on interaction between Na(+)/K(+)-ATPase and H(2)O(2). We demonstrate that in vitro the Na(+)/K(+)-ATPase, a non heme-protein, is able to disproportionate H(2)O(2) catalatically into dioxygen and water, as well as C(40) catalase. By polarography, we quantify O(2) production and by Raman spectroscopy H(2)O(2) consumption. A comparative analysis of kinetics parameters relative to O(2) production shows that for Na(+)/K(+)-ATPase the affinity of the catalytic site able to transform H(2)O(2) into O(2) is twice weaker than that for C(40) catalase. It also shows that the molar activity for O(2) production is 300-fold weaker for ATPase than for catalase. Inhibitors, pH and GSH studies highlight the differences between the heme- and nonheme-proteins. Indeed, for C(40), NaN(3) is strongly inhibiting, but much less for ATPase. The pH range for the catalatic activity of ATPase is wide (6.5 to 8.5), while it is not for C(40) catalase (optimum at pH 8). The Na(+)/K(+)-ATPase catalatic activity is reduced in presence of glutathione, while it is not the case with C(40) catalase. |
| Databáze: | OpenAIRE |
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