Literature summary for 1.1.1.153 extracted from

Sueoka, T.; Katoh, S.
Purification and characterization of sepiapterin reductase from rat erythrocytes (1982), Biochim. Biophys. Acta, 717, 265-271.

Search for more literature for 1.1.1.153

Inhibitors

Inhibitors	Comment	Organism	Structure
Cibacron Blue 3G-A	IC50 0.01 mM	Rattus norvegicus
dihydrobiopterin	non-competitive with NADPH or sepiapterin as varying substrate	Rattus norvegicus
NADP+	competitive inhibition at fixed concentration with varied NADPH, noncompetitive with varied sepiapterin	Rattus norvegicus
NADPH	product inhibition, with more than 0.1 mM, with 0.05 mM sepiapterin	Rattus norvegicus
sepiapterin	product inhibition, with more than 0.05 mM, with 0.1 mM NADPH	Rattus norvegicus

KM Value [mM]

KM Value [mM]	KM Value Maximum [mM]	Substrate	Comment	Organism	Structure
0.0017	-	NADPH	-	Rattus norvegicus
0.015	-	sepiapterin	-	Rattus norvegicus

Molecular Weight [Da]

Molecular Weight [Da]	Molecular Weight Maximum [Da]	Comment	Organism
27500	-	2 * 27500, SDS-PAGE	Rattus norvegicus
55000	-	gel filtration	Rattus norvegicus

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
6-(S)-lactoyl-7,8-dihydropterin + NADPH	Rattus norvegicus	equilibrium lies much in favor of dihydrobiopterin formation	6-(L-erythro-1',2'-dihydroxypropyl)-7,8-dihydropterin + NADP+	-	?
6-(S)-lactoyl-7,8-dihydropterin + NADPH	Rattus norvegicus	terminal step in the biosynthetic pathway for tetrahydrobiopterin	6-(L-erythro-1',2'-dihydroxypropyl)-7,8-dihydropterin + NADP+	-	?

Organism

Organism	UniProt	Comment	Textmining
Rattus norvegicus	-	-	-

Purification (Commentary)

Purification (Comment)	Organism
-	Rattus norvegicus

Reaction

Reaction	Comment	Organism	Reaction ID
L-erythro-7,8-dihydrobiopterin + NADP+ = sepiapterin + NADPH + H+	ordered bi-bi mechanism, NADPH binds first and NADP+ releases last	Rattus norvegicus	a

Source Tissue

Source Tissue	Comment	Organism	Textmining
erythrocyte	-	Rattus norvegicus	-

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
18	-	-	Rattus norvegicus

Storage Stability

Storage Stability	Organism
-80°C, in 50 mM potassium phosphate buffer, 0,1 M KCl, pH 6.8	Rattus norvegicus

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
6-(S)-lactoyl-7,8-dihydropterin + NADPH	equilibrium lies much in favor of dihydrobiopterin formation	Rattus norvegicus	6-(L-erythro-1',2'-dihydroxypropyl)-7,8-dihydropterin + NADP+	-	?
6-(S)-lactoyl-7,8-dihydropterin + NADPH	terminal step in the biosynthetic pathway for tetrahydrobiopterin	Rattus norvegicus	6-(L-erythro-1',2'-dihydroxypropyl)-7,8-dihydropterin + NADP+	-	?

Subunits

Subunits	Comment	Organism
homodimer	2 * 27500, SDS-PAGE	Rattus norvegicus

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
5.5	-	in potassium phosphate buffer	Rattus norvegicus

pH Range

pH Minimum	pH Maximum	Comment	Organism
5.5	7.4	pH 5.5: optimum, pH 7.4: in 50 mM Tris-HCl buffer about 80% of maximum activity observed	Rattus norvegicus

Cofactor

Cofactor	Comment	Organism	Structure
NADPH	-	Rattus norvegicus

IC50 Value

IC50 Value	IC50 Value Maximum	Comment	Organism	Inhibitor	Structure
0.01	-	IC50 0.01 mM	Rattus norvegicus	Cibacron Blue 3G-A

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Release 2023.1 (January 2023)