ID 1.5.1.33 DE pteridine reductase. AN pteridine reductase 1. AN PTR1. CA (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin + 2 NADP(+) = 2 H(+) + CA L-erythro-biopterin + 2 NADPH. CC -!- The enzyme from Leishmania (both amastigote and promastigote forms) CC catalyzes the NADPH-dependent reduction of folate and a wide variety CC of unconjugated pterins, including biopterin, to their tetrahydro CC forms. CC -!- It also catalyzes the reduction of 7,8-dihydropterins and 7,8- CC dihydrofolate to their tetrahydro forms. CC -!- In contrast to EC 1.5.1.3 and EC 1.5.1.34, pteridine reductase will CC not catalyze the reduction of the quinonoid form of dihydrobiopterin. CC -!- The enzyme is specific for NADPH; no activity has been detected with CC NADH. CC -!- It also differs from EC 1.5.1.3 in being specific for the B side of CC NADPH. CC -!- Formerly EC 1.1.1.253. DR Q01782, PTR1_LEIMA ; P42556, PTR1_LEITA ; //