Oxidation of Hypoxanthine to Uric Acid bystreptomyces

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 ...

Uric acid is the final oxidation product of purine metabo-

lism. Severe changes in the concentration of uric acid causes several diseases such as gout, hyperuricemia and Lesch–Nyhan syndrome. Therefore, the accurate determination of uric acid in urine samples can be a powerful indicator of diagnosing diseases. Thus, many researchers have focused to develop a simple, sensitive and accurate method for determining uric acid. Various methods have been deve...

Overproduction of uric acid in hypoxanthine-guanine phosphoribosyltransferase deficiency. Contribution by impaired purine salvage.

The contribution of reduced purine salvage to the hyperuricemia associated with hypoxanthine-guanine phosphoribosyltransferase deficiency was measured by the intravenous administration of tracer doses of [8-(14)C]adenine to nine patients with normal enzyme activity, three patients with a partial deficiency of hypoxanthine-guanine phosphoribosyltransferase, and six patients with the Lesch-Nyhan ...

Changes in plasma concentrations of hypoxanthine and uric acid before and after hemodialysis.

INTRODUCTION Purine metabolites constitute a major class of uremic toxins, and reliable characterization of which helps nephrologists to choose the most appropriate treatment for the patients individually. In the present study, we assessed plasma concentrations of hypoxanthine and uric acid as purine metabolites in patients on maintenance hemodialysis, before and after a dialysis session. MAT...

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