In enzymology, a pteridine reductase () is an enzyme that catalyzes the chemical reaction
5,6,7,8-tetrahydrobiopterin + 2 NADP+ biopterin + 2 NADPH + 2 H+
Thus, the two substrates of this enzyme are 5,6,7,8-tetrahydrobiopterin and NADP+, whereas its 3 products are biopterin, NADPH, and H+.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 5,6,7,8-tetrahydrobiopterin:NADP+ oxidoreductase. Other names in common use include PTR1, and pteridine reductase 1.
Structural studies
As of late 2007, 7 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , and .