title: Xanthine dehydrogenase electrocatalysis: autocatalysis and novel activity.
abstract: The enzyme xanthine dehydrogenase (XDH) from the purple photosynthetic bacterium Rhodobacter capsulatus catalyzes the oxidation of hypoxanthine to xanthine and xanthine to uric acid as part of purine metabolism. The native electron acceptor is NAD(+) but herein we show that uric acid in its 2-electron oxidized form is able to act as an artificial electron acceptor from XDH in an electrochemically driven catalytic system. Hypoxanthine oxidation is also observed with the novel production of uric acid in a series of two consecutive 2-electron oxidation reactions via xanthine. XDH exhibits native activity in terms of its pH optimum and inhibition by allopurinol.
authors.affiliation: Centre for Metals in Biology, School of Chemistry and Molecular Biosciences, University of Queensland , Brisbane, 4072, Australia and.
authors.forename: Palraj
authors.initials: P
authors.lastname: Kalimuthu
authors.forename: Silke
authors.initials: S
authors.lastname: Leimkühler
authors.forename: Paul V
authors.initials: PV
authors.lastname: Bernhardt
mesh_terms: D000493:Allopurinol / Q000737:chemistry; D055162:Biocatalysis; D004563:Electrochemistry; D004566:Electrodes; D005182:Flavin-Adenine Dinucleotide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D019271:Hypoxanthine / Q000737:chemistry; D007097:Imines / Q000737:chemistry; D009243:NAD / Q000737:chemistry; D010084:Oxidation-Reduction; D016354:Rhodobacter capsulatus / Q000737:chemistry; D014527:Uric Acid / Q000031:analogs & derivatives / Q000737:chemistry; D019820:Xanthine / Q000737:chemistry; D014968:Xanthine Dehydrogenase / Q000037:antagonists & inhibitors / Q000737:chemistry*
chemical_list: D007097:Imines; D009243:NAD; D005182:Flavin-Adenine Dinucleotide; D019820:Xanthine; D014527:Uric Acid; D019271:Hypoxanthine; D000493:Allopurinol; D014968:Xanthine Dehydrogenase