Reaction: xanthine + NAD+ + H2O = urate + NADH + H+
For diagram of reaction click here
Glossary: 4-mercuribenzoate = (4-carboxylatophenyl)mercury
Other name(s): NAD+-xanthine dehydrogenase; xanthine-NAD+ oxidoreductase; xanthine/NAD+ oxidoreductase; xanthine oxidoreductase
Systematic name: xanthine:NAD+ oxidoreductase
Comments: Acts on a variety of purines and aldehydes, including hypoxanthine. The mammalian enzyme can also convert all-trans retinol to all-trans-retinoate, while the substrate is bound to a retinoid-binding protein [14]. The enzyme from eukaryotes contains [2Fe-2S], FAD and a molybdenum centre. The mammalian enzyme predominantly exists as the NAD-dependent dehydrogenase (EC 1.17.1.4). During purification the enzyme is largely converted to an O2-dependent form, xanthine oxidase (EC 1.17.3.2). The conversion can be triggered by several mechanisms, including the oxidation of cysteine thiols to form disulfide bonds [2,6,8,15] [which can be catalysed by EC 1.8.4.7, enzyme-thiol transhydrogenase (glutathione-disulfide) in the presence of glutathione disulfide] or limited proteolysis, which results in irreversible conversion. The conversion can also occur in vivo [2,7,15].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 9054-84-6
References:
1. Battelli, M.G. and Lorenzoni, E. Purification and properties of a new glutathione-dependent thiol:disulphide oxidoreductase from rat liver. Biochem. J. 207 (1982) 133-138. [PMID: 6960894]
2. Della Corte, E. and Stirpe, F. The regulation of rat liver xanthine oxidase. Involvement of thiol groups in the conversion of the enzyme activity from dehydrogenase (type D) into oxidase (type O) and purification of the enzyme. Biochem. J. 126 (1972) 739-745. [PMID: 4342395]
3. Parzen, S.D. and Fox, A.S. Purification of xanthine dehydrogenase from Drosophila melanogaster. Biochim. Biophys. Acta 92 (1964) 465-471. [PMID: 14264879]
4. Rajagopalan, K.V. and Handler, P. Purification and properties of chicken liver xanthine dehydrogenase. J. Biol. Chem. 242 (1967) 4097-4107. [PMID: 4294045]
5. Smith, S.T., Rajagopalan, K.V. and Handler, P. Purification and properties of xanthine dehydroganase from Micrococcus lactilyticus. J. Biol. Chem. 242 (1967) 4108-4117. [PMID: 6061702]
6. Ikegami, T. and Nishino, T. The presence of desulfo xanthine dehydrogenase in purified and crude enzyme preparations from rat liver. Arch. Biochem. Biophys. 247 (1986) 254-260. [PMID: 3459393]
7. Engerson, T.D., McKelvey, T.G., Rhyne, D.B., Boggio, E.B., Snyder, S.J. and Jones, H.P. Conversion of xanthine dehydrogenase to oxidase in ischemic rat tissues. J. Clin. Invest. 79 (1987) 1564-1570. [PMID: 3294898]
8. Saito, T., Nishino, T. and Tsushima, K. Interconversion between NAD-dependent and O2-dependent types of rat liver xanthine dehydrogenase and difference in kinetic and redox properties between them. Adv. Exp. Med. Biol. 253B (1989) 179-183. [PMID: 2610112]
9. Parschat, K., Canne, C., Hüttermann, J., Kappl, R. and Fetzner, S. Xanthine dehydrogenase from Pseudomonas putida 86: specificity, oxidation-reduction potentials of its redox-active centers, and first EPR characterization. Biochim. Biophys. Acta 1544 (2001) 151-165. [PMID: 11341925]
10. Ichida, K., Amaya, Y., Noda, K., Minoshima, S., Hosoya, T., Sakai, O., Shimizu, N. and Nishino, T. Cloning of the cDNA encoding human xanthine dehydrogenase (oxidase): structural analysis of the protein and chromosomal location of the gene. Gene 133 (1993) 279-284. [PMID: 8224915]
11. Enroth, C., Eger, B.T., Okamoto, K., Nishino, T., Nishino, T. and Pai, E.F. Crystal structures of bovine milk xanthine dehydrogenase and xanthine oxidase: structure-based mechanism of conversion. Proc. Natl. Acad. Sci. USA 97 (2000) 10723-10728. [PMID: 11005854]
12. Truglio, J.J., Theis, K., Leimkuhler, S., Rappa, R., Rajagopalan, K.V. and Kisker, C. Crystal structures of the active and alloxanthine-inhibited forms of xanthine dehydrogenase from Rhodobacter capsulatus. Structure 10 (2002) 115-125. [PMID: 11796116]
13. Hille, R. The mononuclear molybdenum enzymes. Chem. Rev. 96 (1996) 2757-2816. [PMID: 11848841]
14. Taibi, G., Di Gaudio, F. and Nicotra, C.M. Xanthine dehydrogenase processes retinol to retinoic acid in human mammary epithelial cells. J. Enzyme Inhib. Med. Chem. 23 (2008) 317-327. [PMID: 18569334]
15. Nishino, T., Okamoto, K., Eger, B.T., Pai, E.F. and Nishino, T. Mammalian xanthine oxidoreductase - mechanism of transition from xanthine dehydrogenase to xanthine oxidase. FEBS J. 275 (2008) 3278-3289. [PMID: 18513323]