1.17.3.2	xanthine + H2O + O2 = urate + H2O2	catalytic mechanism of xanthine oxidoreductase, overview	705243	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	favored mechanism for the reaction with xanthine, overview	716010	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	hydrogen-bonding arrangement of the substrate-bound complex at the active site, and proposed mechanism of the purine oxidation reaction by XOR	674374	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	mechanism	393008, 644645	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	mechanism of the reductive half-reaction of xanthine oxidase	745314	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	reaction mechanism for xanthine oxidase, overview. Catalysis is initiated by base-assisted nucleophilic attack of the equatorial Mo-OH on the C-8 carbon of xanthine with concomitant hydride transfer from C-8 to Mo=S, which simultaneously results in reduction of Mo(VI) to Mo(IV). Reoxidation of the molybdenum center occurs by electron transfer to the other redox-active centers of the enzyme, accompanied by deprotonation of the Mo-SH bond and displacement of bound product by hydroxide from solvent to regenerate the Mo-OH group	715538	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	reaction mechanism of XOR and binding modes of the substrate xanthine, overview. The oxidative hydroxylation of purine substrates takes place at the molybdenum center. Reducing equivalents introduced there are then transferred via two [2Fe-2S] centers to the FAD cofactor where reduction of the physiological electron acceptors occurs, NAD+ in the case of the dehydrogenase form, XDH, or O2 in the oxidase form, XO, of the enzyme occur	715273	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	reaction mechanism, detailed overview. The reaction is initiated by proton abstraction from the Mo-OH group by Glu1261, the active-site base, followed by nucleophilic attack on the carbon to be hydroxylated, and hydride transfer to the Mo-S double bond. Suitable substrate orientation, overview. Arg880 is involved in stablizing the transition state in the course of nucleophilic attack, overview	715158	
1.17.3.2	xanthine + H2O + O2 = urate + H2O2	the catalytic reaction of xanthine oxidase is initiated by abstraction of a proton from the Mo-OH group by a conserved active site glutamate residue. The oxidative hydroxylation of xanthine to uric acid takes place at the molybdenum center and results in the two-electron reduction of the metal from Mo(VI) to Mo(IV). The enzyme is subsequently re-oxidized by NAD+ or molecular oxygen in a reaction that occurs at the FAD cofactor	-, 745064