Enzyme Activity Measurement of Xanthine Dehydrogenase

Creative Enzymes provides activity measurement services that rapidly deliver reliable results. Our service quality far exceeds the average level in the enzyme service industry. Our enzymologists hold a professional attitude and make every effort to perfecting every testing service. The measurement of lactate xanthine dehydrogenase is based on our precise spectrophotometric assay.

Xanthine dehydrogenases exist in both eukaryotic and prokaryotic species but show differences in subunit composition and structures. This enzyme catalyzes the hydroxylation of either hypoxanthine to xanthine or xanthine to uric acid. The mammalian enzyme can also convert all-trans retinol to all-trans-retinoate. The eukaryotic enzyme consists of independent subunits, and each subunit contains one molybdopterin and two [2Fe-2S] clusters. This enzyme uses FAD as the cofactor, and the reduction needs NAD⁺ as acceptor.

In mammals, xanthine dehydrogenase (XDH) can be converted to its xanthine oxidase (XO) form, either reversibly by disulfide formation or irreversibly by proteolytic cleavage, the transformation that plays important roles in physiological and pathological processes. This enzyme mainly participates in the purine nucleobases degradation, for both adenosine nucleotides and guanosine nucleotides. Besides, it also takes part in theophylline degradation and urate biosynthesis. As for bacteria, this enzyme degrades caffeine via demethylation reactions. The deficiency of xanthine dehydrogenase has major effects on human physical health. The disorder of purine metabolism causes xanthinuria, a condition that patients show high concentrations of xanthine in blood and urine, and suffer diseases such as renal failure and xanthine kidney stones. Studies also suggest that this disease may contribute to adult respiratory stress syndrome as well as potentiate influenza infection through an oxygen metabolite-dependent mechanism. Considering the pivotal position in growth and metabolism, an increasing number of studies have set about on this enzyme, aiming at its huge potential in clinical drug development. Creative Enzymes has specialized experts and the smartest instrument, and is able to provide assay services for xanthine dehydrogenase activity testing.

Figure: The crystal structure of bovine milk xanthine dehydrogenase with NADH bound.
Reference: Ishikita, H. et al. J.Am.Chem.Soc. 2012 134: 999-1009.

Creative Enzymes has always had strong presence in activity testing for xanthine dehydrogenase. The high-quality results are guaranteed by our profession protocols and in-depth studies. Creative Enzymes is widely trusted by tens of thousands of clients and enjoys good reputation in the enzyme service industry.