Oxidation-Reduction Potentials of Hypoxanthine Xanthine and Xanthine Uric Acid

Xanthine oxidase catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid as follows

The enzyme is well-suited to carry out the catalysis of these oxidative reactions, containing as it does four redox-active sites: molybdenum, flavin adenine dinucleotide (FAD) and a pair of iron-sulfur centers of the ferredoxin type (Fe2S2). The purine substrates interact with the enzyme at the molybdenum site of xanthine oxidase and oxygen at the flavin site. The two metabolic reactions above ...

Steps in the oxidation of xanthine to uric acid catalysed by milk xanthine oxidase.

The reduction of cytochrome c by hypoxanthine and xanthine oxidase.

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A kinetic study of hypoxanthine oxidation by milk xanthine oxidase.

The course of the reaction sequence hypoxanthine----xanthine----uric acid catalysed by xanthine:oxygen oxidoreductase from milk was investigated on the basis of u.v. spectra taken during the course of hypoxanthine and xanthine oxidations. It was found that xanthine accumulated in the reaction mixture when hypoxanthine was used as a substrate. The time course of the concentrations of hypoxanthin...

Uric acid and xanthine oxidoreductase in wound healing.

Chronic wounds are an important health problem because they are difficult to heal and treatment is often complicated, lengthy and expensive. For a majority of sufferers the most common outcomes are long-term immobility, infection and prolonged hospitalisation. There is therefore an urgent need for effective therapeutics that will enhance ulcer healing and patient quality of life, and will reduc...