Inhibitors | Comment | Organism | Structure |
---|---|---|---|
aminopterin | the DHFR inhibitor aminopterin inhibits tetrahydrobiopterin recycling. Aminopterin has no effect alone but slightly reduced L-citrulline formation and cGMP accumulation in the presence of dihydrobiopterin | Homo sapiens | |
aminopterin | the DHFR inhibitor aminopterin inhibits tetrahydrobiopterin recycling. Aminopterin has no effect alone but slightly reduced L-citrulline formation and cGMP accumulation in the presence of dihydrobiopterin | Sus scrofa |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | Michaelis-Menten kinetics of dihydrofolate reductase-catalyzed (6R)-5,6,7,8-tetrahydro-L-biopterin recycling, the enzyme shows high affinity for dihydrobiopterin | Sus scrofa | |
additional information | - |
additional information | MichaelisMenten kinetics of dihydrofolate reductase-catalyzed (6R)-5,6,7,8-tetrahydro-L-biopterin recycling | Homo sapiens |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
cytosol | - |
Homo sapiens | 5829 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
6,7-dihydropteridine + NADPH + H+ | Homo sapiens | - |
5,6,7,8-tetrahydropteridine + NADP+ | - |
r | |
6,7-dihydropteridine + NADPH + H+ | Sus scrofa | - |
5,6,7,8-tetrahydropteridine + NADP+ | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | P09417 | - |
- |
Sus scrofa | Q8MJ30 | - |
- |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
aorta | - |
Sus scrofa | - |
endothelial cell | - |
Homo sapiens | - |
endothelial cell | aortic | Sus scrofa | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
6,7-dihydropteridine + NADPH + H+ | - |
Homo sapiens | 5,6,7,8-tetrahydropteridine + NADP+ | - |
r | |
6,7-dihydropteridine + NADPH + H+ | - |
Sus scrofa | 5,6,7,8-tetrahydropteridine + NADP+ | - |
r |
Synonyms | Comment | Organism |
---|---|---|
DHPR | - |
Homo sapiens |
DHPR | - |
Sus scrofa |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Homo sapiens |
37 | - |
assay at | Sus scrofa |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.4 | - |
assay at | Homo sapiens |
7.4 | - |
assay at | Sus scrofa |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADP+ | - |
Homo sapiens | |
NADP+ | - |
Sus scrofa | |
NADPH | - |
Homo sapiens | |
NADPH | - |
Sus scrofa |
General Information | Comment | Organism |
---|---|---|
metabolism | inhibition of de novo biosynthesis of tetrahydrobiopterin by preincubating the cells for 24 h with the GTP cyclohydrolase inhibitor DAHP (10 mM) diminishes L-citrulline formation. Addition of dihydrobiopterin fully restores L-citrulline formation. In addition to its effect on arginine-to-citrulline conversion, pretreatment of the cells with DAHP reduces A23187-induced cGMP accumulation. Addition of tetrahydrobiopterin or dihydrobiopterin not only antagonizes the inhibitory effect of DAHP but also increases cGMP accumulation. (6R)-5,6,7,8-Tetrahydro-L-biopterin availability regulates nitric oxide and superoxide formation by endothelial nitric oxide synthase (eNOS). At low tetrahydrobiopterin or low tetrahydrobiopterin to 7,8-dihydrobiopterin ratios the enzyme becomes uncoupled and generates superoxide at the expense of NO | Sus scrofa |
metabolism | inhibition of de novo biosynthesis of tetrahydrobiopterin by preincubating the cells for 24 h with the GTP cyclohydrolase inhibitor dihydroxyacetone phosphate (10 mM) diminishes L-citrulline formation. Addition of dihydrobiopterin fully restores L-citrulline formation. In addition to its effect on arginine-to-citrulline conversion, pretreatment of the cells with dihydroxyacetone phosphate reduces A23187-induced cGMP accumulation. Addition of tetrahydrobiopterin or dihydrobiopterin not only antagonizes the inhibitory effect of dihydroxyacetone phosphate but also increases cGMP accumulation. (6R)-5,6,7,8-Tetrahydro-L-biopterin availability regulates nitric oxide and superoxide formation by endothelial nitric oxide synthase (eNOS). At low tetrahydrobiopterin or low tetrahydrobiopterin to 7,8-dihydrobiopterin ratios the enzyme becomes uncoupled and generates superoxide at the expense of NO | Homo sapiens |
physiological function | the enzyme catalyzes (6R)-5,6,7,8-tetrahydro-L-biopterin recycling in endothelial cytosols | Homo sapiens |
physiological function | the enzyme catalyzes (6R)-5,6,7,8-tetrahydro-L-biopterin recycling in endothelial cytosols with high affinity for dihydrobiopterin | Sus scrofa |