Activating Compound | Comment | Organism | Structure |
---|---|---|---|
4,4'-dithiodipyridine | reverses conversion of dehydrogenase to oxidase form | Bos taurus | |
DTT | recovery from oxidase to dehydrogenase type | Bos taurus |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
GSH | 45% of the oxidase activity converted to dehydrogenase activity at 10 mM | Bos taurus | |
GSSG | 75% of the dehydrogenase activity converted to oxidase activity at 0.5 mM | Bos taurus | |
NADH | partial reduction of dehydrogenase activity under anaeroboic conditions, oxidase activity more slowly reduced | Bos taurus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0003 | - |
xanthine | electron acceptor: NAD+ | Bos taurus | |
0.0067 | - |
NAD+ | electron donor: xanthine | Bos taurus | |
0.012 | - |
xanthine | electron acceptor: oxygen | Bos taurus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Iron-sulfur-center | 2 Fe2-S2-clusters | Bos taurus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
xanthine + NAD+ + H2O | Bos taurus | xanthine dehydrogenase form has distinct xanthine/oxygen activity, 35-42% of electrons transferred to O2 to form O2- | urate + NADH | - |
? | |
xanthine + O2 + H2O | Bos taurus | xanthine oxidase form transfers 22% electrons to oxygen to form superoxide | urate + O2- + 2 H+ | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bos taurus | - |
- |
- |
Purification (Comment) | Organism |
---|---|
to homogeneity, presence of DTT required for purification of the dehydrogenase form | Bos taurus |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
milk | - |
Bos taurus | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.16 | - |
xanthine oxidase activity | Bos taurus |
1.56 | - |
xanthine dehydrogenase activity | Bos taurus |
Storage Stability | Organism |
---|---|
-70°C, 0.1 M sodium diphosphate, 0.3 mM EDTA, pH 7.5, 1 mM salicylate, 2.5 mM DTT, 3 months | Bos taurus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
xanthine + 2,6-dichlorophenolindophenol + H2O | - |
Bos taurus | urate + ? | - |
? | |
xanthine + NAD+ + H2O | xanthine dehydrogenase form has distinct xanthine/oxygen activity, 35-42% of electrons transferred to O2 to form O2- | Bos taurus | urate + NADH | - |
? | |
xanthine + O2 + H2O | xanthine oxidase form transfers 22% electrons to oxygen to form superoxide | Bos taurus | urate + O2- + 2 H+ | - |
? |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
6.33 | - |
xanthine | electron acceptor: NAD+ | Bos taurus | |
15 | - |
xanthine | electron acceptor: oxygen | Bos taurus |
pH Stability | pH Stability Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
stable at 4°C, one day, absence of DTT | Bos taurus |
8.5 | - |
4°C, absence of DTT, marked decrease of activity within hours | Bos taurus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | deflavo-enzyme completely loses xanthine/NAD+ activity, no loss of xanthine/2,6-dichorophenolindophenol activity, xanthine dehydrogenase form stabilizes the neutral form of flavin, xanthine oxidase form does not | Bos taurus | |
additional information | - |
Bos taurus | |
NAD+ | - |
Bos taurus |