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Updated: Jun 19, 2026
11:56
A Rapid and Specific Microplate Assay for the Determination of Intra- and Extracellular Ascorbate in Cultured Cells
Published on: April 11, 2014
ON THE INACTIVATION OF ASCORBIC ACID OXIDASE
1Department of Chemistry, Columbia University, New York.
The Journal of General Physiology
|October 30, 2009
Summary
Ascorbic acid oxidase rapidly inactivates during ascorbic acid oxidation. Protective agents like catalase and peroxidase prevent this reaction inactivation, suggesting a role for reactive oxygen species.
Area of Science:
- Biochemistry
- Enzymology
Background:
- Ascorbic acid oxidase is crucial for ascorbic acid oxidation.
- Enzyme inactivation during reaction can limit experimental outcomes.
Purpose of the Study:
- Investigate the causes of ascorbic acid oxidase inactivation during ascorbic acid oxidation.
- Identify protective agents and mechanisms against this inactivation.
Main Methods:
- Enzymatic oxidation of ascorbic acid using purified ascorbic acid oxidase.
- Measurement of oxygen uptake to quantify enzyme inactivation.
- Addition of various substances (proteins, metal complexes) to assess protective effects.
Main Results:
- Ascorbic acid oxidase undergoes rapid inactivation during ascorbic acid oxidation.
- Environmental factors contribute minorly, while an inherent system factor, possibly reactive oxygen, is the major cause.
- Native catalase, peroxidase, methemoglobin, and hemin significantly protect the oxidase.
- Protective agents do not interfere with oxygen uptake or hydrogen peroxide removal.
Conclusions:
- Ascorbic acid oxidase inactivation is primarily an intrinsic property of the reaction system.
- Reactive oxygen species are implicated in the inactivation process.
- Specific iron-porphyrin compounds offer protection, highlighting potential mechanisms for enzyme stabilization.
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