Inhibitors | Comment | Organism | Structure |
---|---|---|---|
additional information | paraformaldehyde fixation of rat brain abolishes NOS activity in particulate and cytosolic fractions | Rattus norvegicus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | in heme | Rattus norvegicus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 L-arginine + 3 NADPH + 3 H+ + 4 O2 | Rattus norvegicus | overall reaction | 2 L-citrulline + 2 nitric oxide + 3 NADP+ + 4 H2O | - |
? | |
2 L-arginine + 3 NADPH + 3 H+ + 4 O2 | Rattus norvegicus Sprague-Dawley | overall reaction | 2 L-citrulline + 2 nitric oxide + 3 NADP+ + 4 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Rattus norvegicus | P29476 | - |
- |
Rattus norvegicus Sprague-Dawley | P29476 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
brain | - |
Rattus norvegicus | - |
brain stem | - |
Rattus norvegicus | - |
cerebellum | - |
Rattus norvegicus | - |
ganglion | coeliac ganglia | Rattus norvegicus | - |
additional information | determination of NADPH diaphorase staining in preganglionic terminals, staining generally ascribed to NADH diaphorase activity in aldehyde-treated tissues | Rattus norvegicus | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 L-arginine + 3 NADPH + 3 H+ + 4 O2 | overall reaction | Rattus norvegicus | 2 L-citrulline + 2 nitric oxide + 3 NADP+ + 4 H2O | - |
? | |
2 L-arginine + 3 NADPH + 3 H+ + 4 O2 | overall reaction | Rattus norvegicus Sprague-Dawley | 2 L-citrulline + 2 nitric oxide + 3 NADP+ + 4 H2O | - |
? | |
additional information | the similar spatial distribution of NADPH diaphorase and nitric oxide synthase (NOS) in aldehyde-treated tissues has lead to the postulation that the catalytic activity of NOS promotes NADPH-dependent reduction of nitro-blue tetrazolium (NBT) to insoluble readily visualized diformazan particles. Since NADPH cannot directly reduce NBT, it is argued that NBT binds to NOS at the flavin electron transport domain and is reduced by a NOS form, which is previously reduced by beta-NADPH. However, paraformaldehyde fixation of rat brain abolishes NOS activity in particulate and cytosolic fractions and although fixation abolishes NADPH diaphorase in the particulate fraction, 50-60% of NADPH diaphorase activity remains in the cytosolic fraction. This suggests that cytosolic NADPH diaphorase in aldehyde-treated tissues results from a factor other than NOS. NOS contains heme iron, flavin adenine dinucleotide and flavin mononucleotide. NADPH-dependent reduction of NBT in aldehyde-treated tissues is not directly due to NOS because metal chelators that inhibit activity of metalloenzymes and deflavinating agents do not eliminate NADPH diaphorase. While the NOS active site is not required to promote the NADPH-dependent reduction of NBT, some other reactive site of the protein could still be involved. SNOs exist in cytoplasmic vesicles of endothelial cells of rat small mesenteric arteries, SNOs promote the NADPH-dependent reduction of NBT, both alpha-NADPH and beta-NADPH promote the reduction of NBT to diformazan and since alpha-NADPH will not donate electrons to NOS, it is unlikely that diformazan is the result of an increase in the catalytic activity of NOS, prior depletion of SNOs in tissues markedly reduces subsequent NADPH diaphorase staining. NADPH diaphorase activity in aldehyde-treated tissues is due to preformed pools of SNOs that facilitate NADPH-dependent reduction of NBT to diformazan | Rattus norvegicus | ? | - |
- |
|
additional information | the similar spatial distribution of NADPH diaphorase and nitric oxide synthase (NOS) in aldehyde-treated tissues has lead to the postulation that the catalytic activity of NOS promotes NADPH-dependent reduction of nitro-blue tetrazolium (NBT) to insoluble readily visualized diformazan particles. Since NADPH cannot directly reduce NBT, it is argued that NBT binds to NOS at the flavin electron transport domain and is reduced by a NOS form, which is previously reduced by beta-NADPH. However, paraformaldehyde fixation of rat brain abolishes NOS activity in particulate and cytosolic fractions and although fixation abolishes NADPH diaphorase in the particulate fraction, 50-60% of NADPH diaphorase activity remains in the cytosolic fraction. This suggests that cytosolic NADPH diaphorase in aldehyde-treated tissues results from a factor other than NOS. NOS contains heme iron, flavin adenine dinucleotide and flavin mononucleotide. NADPH-dependent reduction of NBT in aldehyde-treated tissues is not directly due to NOS because metal chelators that inhibit activity of metalloenzymes and deflavinating agents do not eliminate NADPH diaphorase. While the NOS active site is not required to promote the NADPH-dependent reduction of NBT, some other reactive site of the protein could still be involved. SNOs exist in cytoplasmic vesicles of endothelial cells of rat small mesenteric arteries, SNOs promote the NADPH-dependent reduction of NBT, both alpha-NADPH and beta-NADPH promote the reduction of NBT to diformazan and since alpha-NADPH will not donate electrons to NOS, it is unlikely that diformazan is the result of an increase in the catalytic activity of NOS, prior depletion of SNOs in tissues markedly reduces subsequent NADPH diaphorase staining. NADPH diaphorase activity in aldehyde-treated tissues is due to preformed pools of SNOs that facilitate NADPH-dependent reduction of NBT to diformazan | Rattus norvegicus Sprague-Dawley | ? | - |
- |
Synonyms | Comment | Organism |
---|---|---|
NADPH diaphorase | - |
Rattus norvegicus |
NADPH-d | - |
Rattus norvegicus |
nNOS | - |
Rattus norvegicus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
22 | - |
assay at room temperature | Rattus norvegicus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Rattus norvegicus |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
beta-NADPH | - |
Rattus norvegicus | |
FAD | - |
Rattus norvegicus | |
heme | - |
Rattus norvegicus |