Xanthine Dehydrogenase (XDH)

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.The three substrates of this enzyme are xanthine, NAD+, and H2O, whereas its three products are urate, NADH, and H+.This enzyme belongs to the family of oxidoreductases, to be specific, those acting on CH or CH2 group with NAD+ or NADP+ as acceptor.Defects in xanthine dehydrogenase cause xanthinuria, may contribute to adult respiratory stress syndrome, and may potentiate influenza infection through an oxygen metabolite-dependent mechanism.