Introduction Function Structure Property Gout Function In purine

Introduction Function Structure Property Gout

Function In purine degradation, it oxidizes hypoxanthine successively to xanthine and then to uric acid

Stucture Homodimer Each monomer has three domains N-terminal domain (residues 1~165): two Fe/S cofactors FAD-binding domain (residues 226~553) The third domain (residues 590~1332): one molybdenum

Fe/S convert XDH (xanthine dehydrogenase) to XO FAD reduction of O 2 Molybdenum oxidative hydroxylation of purine

Property Ubiquitous among species and within the various tissues Normally it exists in the liver and jejunum determination of serum xanthine oxidase level serves as a sensitive indicator of acute liver damage

In individuals, 90% is XDH form, and 10% is XO form XDH XO (oxidation of sulfhydryl or proteolysis) Difference between XO & XDH: XO XH+H 2 O+O 2 X=O+H 2 O 2 XDH XH+H 2 O+NAD+ X=O+NADH

Other names: xanthine oxidoreductase, hypoxanthine oxidase, hypoxanthine oxidase

Gout A form of arthritis caused by excess uric acid (hyperuricemia) Complication can result death Cause: heredity, diet, fatness, sex, excessive exercise, drug, alcohol, and some diseases

Drug can decrease patients’ pains and prevent it an attack of acute gout: colchicine lower conc. of uric acid: allopurinol