Xanthine dehydrogenase

Function

Xanthine dehydrogenase belongs to the group of molybdenum-containing hydroxylases involved in the oxidative metabolism of purines. The enzyme is a homodimer. Xanthine dehydrogenase can be converted to xanthine oxidase by reversible sulfhydryl oxidation or by irreversible proteolytic modification.

Xanthine dehydrogenase catalyzes the following chemical reaction:

The three substrates of this enzyme are xanthine, NAD⁺, and H₂O, whereas its three products are urate, NADH, and H⁺.

This enzyme participates in purine metabolism.

Nomenclature

This enzyme belongs to the family of oxidoreductases, to be specific, those acting on CH or CH₂ groups with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is xanthine:NAD⁺ oxidoreductase. Other names in common use include NAD⁺-xanthine dehydrogenase, xanthine-NAD⁺ oxidoreductase, xanthine/NAD⁺ oxidoreductase, and xanthine oxidoreductase.

Clinical significance

Defects in xanthine dehydrogenase cause xanthinuria, may contribute to adult respiratory stress syndrome, and may potentiate influenza infection through an oxygen metabolite-dependent mechanism.