Antioxidant activity of hemocyanin; a pulse radiolysis study
| Autor: | Christiane Ferradini, Max Goyffon, Monique Vuillaume, Monique Gardès-Albert, Eric Quéinnec |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
medicine.medical_treatment
Inorganic chemistry Biophysics chemistry.chemical_element Biochemistry Antioxidants Superoxide dismutase chemistry.chemical_compound Reaction rate constant Superoxides Structural Biology medicine Animals Formate Reactivity (chemistry) Arthropods Molecular Biology biology Superoxide Hemocyanin Hydrogen-Ion Concentration Models Theoretical Copper Kinetics chemistry Hemocyanins Radiolysis biology.protein |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1041:153-159 |
| ISSN: | 0167-4838 |
| DOI: | 10.1016/0167-4838(90)90059-o |
| Popis: | In order to determine the reactivity on hemocyanin from Androctonus australis, the reaction of superoxide anion has been investigated using pulse radiolysis. The kinetics of O2− decays have been studied in aqueous buffered media at various basic pH (8, 8.5 and 9), first in the absence and then in the presence of hemocyanin (in oxygenated solutions containing formate anion 0.16 mol•1−. We have shown that, in the presence of hemocyanin, O2− decay is a first-order process whose apparent rate constant is proportional to protein concentration (10−7 to 10−6 mol·1−1) and pH independent between 8 to 9. A second-order rate constant of 3.5±0.1·107 mol−1·1·s−1, has been deduced for the catalytic rate constant of hemocyanin with O2 • . Meanwhile, this activity is smaller than that described for free copper, eukaryotic Cu-Zn-SOD or some copper chelates. We have verified that apohemocyanin — the copper deprived protein — does not exhibit such an activity vs. SOD (superoxide dismutase). |
| Databáze: | OpenAIRE |
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