Activating Compound | Comment | Organism | Structure |
---|---|---|---|
sulfide/dithionite | treatment increases the specific activity of AtXDH1 | Arabidopsis thaliana |
Cloned (Comment) | Organism |
---|---|
expression of His-tagged wild-type and mutant XDH1 variants in Pichia pastoris strain KM71 | Arabidopsis thaliana |
expression of His-tagged XDH1 in Pichia pastoris | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
E1297A | site-directed mutagenis | Arabidopsis thaliana |
E831A | site-directed mutagenis | Arabidopsis thaliana |
R909A | site-directed mutagenis | Arabidopsis thaliana |
W364A | site-directed mutagenis | Arabidopsis thaliana |
Y421A | site-directed mutagenis | Arabidopsis thaliana |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
allopurinol | - |
Arabidopsis thaliana | |
additional information | NAD+ inhibits NADH-dependent superoxide formation of AtXDH1 | Arabidopsis thaliana | |
NADH | suppresses NAD+-dependent xanthine oxidation | Arabidopsis thaliana |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe | a molybdenum-iron-flavoenzyme | Arabidopsis thaliana | |
Iron | a molybdenum-iron-flavoenzyme, contains [2Fe-2S] centers | Arabidopsis thaliana | |
Mo | a molybdenum-iron-flavoenzyme | Arabidopsis thaliana | |
Molybdenum | a molybdenum-iron-flavo enzyme, which contains a C-terminal molybdenum cofactor-binding domain of 85 kDa | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
hypoxanthine + NAD+ + H2O | Arabidopsis thaliana | - |
xanthine + NADH + H+ | - |
? | |
additional information | Arabidopsis thaliana | XDH can be converted into XO, EC 1.17.3.2, either reversibly by oxidation of the sulfhydryl groups of two conserved cysteine residues. Under physiological conditions the XDH form appears to dominate with 80% over the XO form with 20% | ? | - |
? | |
xanthine + NAD+ + H2O | Arabidopsis thaliana | - |
urate + NADH + H+ | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | - |
- |
- |
Arabidopsis thaliana | Q8GUQ8 | - |
- |
Posttranslational Modification | Comment | Organism |
---|---|---|
flavoprotein | - |
Arabidopsis thaliana |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged wild-type and mutant XDH1 variants from Pichia pastoris strain KM71 by nickel affinity chromatography and anion exchange chromatography | Arabidopsis thaliana |
recombinant His-tagged XDH1 from Pichia pastoris by nickel affinity and anion exchange chromatography | Arabidopsis thaliana |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.044 | - |
purified recombinant enzyme, substrate xanthine, pH 8.0 | Arabidopsis thaliana |
0.65 | - |
purified recombinant enzyme, pH 8.0, 25°C | Arabidopsis thaliana |
0.702 | - |
purified recombinant enzyme, substrate NADH, pH 6.6 | Arabidopsis thaliana |
1.712 | - |
purified recombinant enzyme, in presence of sulfide/dithionite | Arabidopsis thaliana |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
hypoxanthine + NAD+ + H2O | - |
Arabidopsis thaliana | xanthine + NADH + H+ | - |
? | |
additional information | XDH can be converted into XO, EC 1.17.3.2, either reversibly by oxidation of the sulfhydryl groups of two conserved cysteine residues. Under physiological conditions the XDH form appears to dominate with 80% over the XO form with 20% | Arabidopsis thaliana | ? | - |
? | |
additional information | AtXDH1 is capable of oxidizing NADH with concomitant formation of NAD+ and superoxide, the specific activity of recombinant AtXDH1 with NADH as substrate is about 15times higher than the activity with xanthine accompanied by a doubling in superoxide production and is dependent on sulfurated molybdenum cofactor, overview. FAD is crucial for NADH-based superoxide formation of AtXDH1, whereas the molybdenum cofactor has only little or no influence on the activity, residues E831, R909, E1297, W364, and Y421 are involved | Arabidopsis thaliana | ? | - |
? | |
additional information | by an alternative activity, AtXDH1 is capable of oxidizing NADH with concomitant formation of NAD+ and superoxide. In comparison to the specific activity with xanthine as substrate, the specific activity of recombinant AtXDH1 with NADH as substrate is about 15times higher. Each sub-activity is determined by specific conditions such as the availability of substrates and co-substrates, which allows regulation of superoxide production by AtXDH1 | Arabidopsis thaliana | ? | - |
? | |
xanthine + NAD+ + H2O | - |
Arabidopsis thaliana | urate + NADH + H+ | - |
? |
Subunits | Comment | Organism |
---|---|---|
homodimer | composed of two identical subunits of about 145 kDa, each being subdivided into three domains: a N-terminal iron-sulfur-binding domain of 20 kDa, a 40 kDa domain harboring a FAD-binding site, and a C-terminal molybdenum cofactor-binding domain of 85 kDa | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
AtXDH1 | - |
Arabidopsis thaliana |
More | mammalian XOR exists in two interconvertible forms, the xanthine dehydrogenase, XDH, form and the xanthine oxidase, XO, form. The primary gene product is XDH, which can be converted into XO | Arabidopsis thaliana |
xanthine oxidoreductase | - |
Arabidopsis thaliana |
XDH1 | - |
Arabidopsis thaliana |
XOR | - |
Arabidopsis thaliana |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Arabidopsis thaliana |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
6.6 | - |
substrate NADH | Arabidopsis thaliana |
8 | - |
assay at | Arabidopsis thaliana |
8 | - |
substrate xanthine | Arabidopsis thaliana |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6.6 | 8 | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | a molybdenum-iron-flavoenzyme | Arabidopsis thaliana | |
FAD | a molybdenum-iron-flavoenzyme, activity-to-flavin ratio of 8 with xanthine as substrate and NAD+ as final electron acceptor, recombinant enzyme | Arabidopsis thaliana | |
molybdenum cofactor | C-terminal | Arabidopsis thaliana | |
additional information | both NAD+ and NADH compete for the same binding site | Arabidopsis thaliana | |
NAD+ | - |
Arabidopsis thaliana | |
NAD+ | NAD+ inhibits NADH oxidase activity of AtXDH1 | Arabidopsis thaliana | |
NADH | suppresses NAD+-dependent xanthine oxidation | Arabidopsis thaliana | |
[2Fe-2S] cluster | two N-terminal non-identical iron-sulfur clusters of the [2Fe-2S]-type | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
additional information | mammalian XOR exists in two interconvertible forms, the xanthine dehydrogenase, XDH, form and the xanthine oxidase, XO, form. The primary gene product is XDH, which can be converted into XO | Arabidopsis thaliana |
physiological function | xanthine oxidoreductase is a ubiquitous molybdenum-iron-flavo enzyme with a central role in purine catabolism where it catalyzes the oxidation of hypoxanthine to xanthine and of xanthine to uric acid | Arabidopsis thaliana |
physiological function | AtXDH1 is a key enzyme in purine degradation where it oxidizes hypoxanthine to xanthine and xanthine to uric acid | Arabidopsis thaliana |