Substrate specificity of ascorbate oxidase
| Autor: | Charles R. Dawson, Jean Dayan |
|---|---|
| Rok vydání: | 1976 |
| Předmět: |
Kinetics
Biophysics chemistry.chemical_element Photochemistry Biochemistry Oxygen Medicinal chemistry Structure-Activity Relationship chemistry.chemical_compound Phenols Spectrophotometry medicine Molecular Biology chemistry.chemical_classification medicine.diagnostic_test Hydroquinone Substrate (chemistry) Cell Biology Hydrogen-Ion Concentration Plants Ascorbic acid Aerobiosis Hydroquinones Enzyme chemistry Ascorbate Oxidase Spectrophotometry Ultraviolet Oxidoreductases Copper |
| Zdroj: | Biochemical and Biophysical Research Communications. 73:451-458 |
| ISSN: | 0006-291X |
| DOI: | 10.1016/0006-291x(76)90728-2 |
| Popis: | Ascorbate oxidase oxidizes leuco 2, 6-dichloroindophenol to the blue quinoid dye and produces spectral changes in the UV spectra of certain substituted polyhydric and amino phenols at pH 5.7. The new peaks produced by the addition of enzyme to the dichlorohydroquinones (2,5 and 2,6) and hydroxyhydroquinone correspond to the respective p-quinones of these substrates. At pH 5.7, the enzyme does not oxidize hydroquinone, barely oxidizes chlorohydroquinone, but oxidizes 2,6- and 2,5-dichlorohydroquinone and hydroxyhydroquinone at a rate about 1 12 that of ascorbic acid, with the uptake of one gram atom of oxygen per mole of substrate. A correlation has been found between the concentration of anion present in solution at pH 5.7 and the rate of oxidation of compounds of the hydroquinone series by the enzyme. The results indicate that an anionic form of the substrate is an important requirement of the enzyme specificity. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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