Inhibitors | Comment | Organism | Structure |
---|---|---|---|
8-hydroxyquinoline | pH 7.5, 20% inhibition at 0.1 mM | Aspergillus nidulans | |
azide | pH 7.5, 90% inhibition at 0.01 mM | Aspergillus nidulans | |
cyanide | pH 7.5, 100% inhibition at 0.01 mM | Aspergillus nidulans | |
iodoacetamide | pH 7.5, 40% inhibition at 1 mM | Aspergillus nidulans | |
additional information | cysteine or dithiothreitol relieve or prevent inhibition. Not inhibited by urea, glutamic acid, aspartic acid and ammonia at 10 mM | Aspergillus nidulans | |
NADP+ | inhibits NADPH oxidation, non-competitive with respect to nitrate | Aspergillus nidulans | |
nitrite | competitive with respect to nitrate and non-competitive to NADPH | Aspergillus nidulans | |
p-hydroxymercuribenzoate | pH 7.5, 85% inhibition at 0.001 mM | Aspergillus nidulans | |
phenanthroline hydrate | pH 7.5, 1:10, 20% inhibition at 0.1 mM | Aspergillus nidulans | |
potassium chlorate | pH 7.5, slight, 20% inhibition at 5 mM | Aspergillus nidulans | |
Sodium nitrite | pH 7.5, slight, 50% inhibition at 5 mM | Aspergillus nidulans |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.009 | - |
NADPH | + nitrate, pH 6.5 and + cytochrome c, pH 7.5 | Aspergillus nidulans | |
0.01 | - |
NADPH | + nitrate, pH 7.5 | Aspergillus nidulans | |
0.015 | - |
NADPH | + cytochrome c, pH 8.5 | Aspergillus nidulans | |
0.024 | - |
cytochrome c | cosubstrate NADPH, pH 8.5 | Aspergillus nidulans | |
0.029 | - |
cytochrome c | cosubstrate NADPH, pH 7.5 | Aspergillus nidulans | |
0.06 | - |
nitrate | cosubstrate NADPH, pH 7.5 | Aspergillus nidulans | |
0.08 | - |
nitrate | cosubstrate NADPH, pH 6.5 | Aspergillus nidulans |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Molybdenum | - |
Aspergillus nidulans | |
phosphate | stimulates, required for maximal activity | Aspergillus nidulans |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
180000 | 200000 | sucrose density gradient, gel-filtration | Aspergillus nidulans |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
nitrate + NADPH | Aspergillus nidulans | - |
nitrite + NADP+ + H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Aspergillus nidulans | - |
bi-1 a, translocation-free biotin auxotroph | - |
Purification (Comment) | Organism |
---|---|
ion-exchange, ammonium sulfate precipitation, gel filtration | Aspergillus nidulans |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
nitrite + NADP+ + H2O = nitrate + NADPH + H+ | random order rapid-equilibrium mechanism, two functional parts: 1. heat labile, FAD and haemoprotein containing, binds NADPH and transfers electrons from NADPH via FAD and perhaps cytochrome b to acceptors such as cytochrome c, 2. heat stable, molybdenum containing, accepts electrons from reduced viologen dyes and transfers them to nitrate | Aspergillus nidulans |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
2.5 | - |
- |
Aspergillus nidulans |
4 | 16.1 | at different stages of purification | Aspergillus nidulans |
Storage Stability | Organism |
---|---|
4°C, half life of 3-5 days | Aspergillus nidulans |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
chlorate + NADPH | lower affinity than to nitrate, appears to be toxic or its product | Aspergillus nidulans | chlorite + NADP+ | - |
? | |
ferricytochrome c + NADPH + H+ | - |
Aspergillus nidulans | ferrocytochrome c + NADP+ + H2O | - |
r | |
nitrate + NADPH | - |
Aspergillus nidulans | nitrite + NADP+ + H2O | - |
? | |
nitrate + NADPH | two associated activities: cytochrome c reductase and reduced viologen dye:nitrate reductase | Aspergillus nidulans | nitrite + NADP+ + H2O | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Aspergillus nidulans |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Aspergillus nidulans |
7.5 | 8 | - |
Aspergillus nidulans |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | stimulated by flavin | Aspergillus nidulans | |
heme | - |
Aspergillus nidulans |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.04 | 0.048 | NADP+ | NADPH as substrate in saturating and non-saturating concentrations, competitive | Aspergillus nidulans | |
0.065 | - |
NADP+ | nitrate as substrate in non-saturating concentrations, non-competitive | Aspergillus nidulans | |
0.15 | - |
nitrite | NADPH as substrate in non-saturation concentration, non-competitive | Aspergillus nidulans | |
0.18 | - |
nitrite | nitrate as substrate in saturating and non-saturating concentrations, competitive | Aspergillus nidulans |