Identification of dihydropteridine reductase in human platelets.

Dopamine-derived tetrahydroisoquinolines. Novel inhibitors of dihydropteridine reductase.

Dopamine-derived tetrahydroisoquinolines, such as 3',4'-deoxynorlaudanosolinecarboxylic acid, higenamine-1-carboxylic acid, higenamine, and salsolinol, inhibit human liver dihydropteridine reductase noncompetitively with Ki values ranging from 1.5 to 90 microM. The enzyme is also inhibited noncompetitively by dopamine (Ki = 6 microM) and aminopterin (Ki = 100 microM) but uncompetitively by phen...

Dihydropteridine reductase: implication on the regulation of catecholamine biosynthesis.

The low tissue concentrations of tetrahydrobiopterin, as well as the antagonism between the catecholamine feedback inhibition of tyrosine hydroxylase and the reduced cofactor concentrations, suggest that dihydropteridine reductase may play an important role in the regulation of catecholamine biosynthesis. The interaction of the different components involved in the hydroxylation of tyrosine was ...

The use of restriction fragment length polymorphisms in prenatal diagnosis of dihydropteridine reductase deficiency.

Using a human dihydropteridine reductase (hDHPR) cDNA probe we have detected two AvaII and one MspI restriction fragment length polymorphisms (RFLPs). We show that these RFLPs are in disequilibrium and calculate that approximately 60% of Caucasians are heterozygous for at least one RFLP. We demonstrate the usefulness of these RFLPs in prenatal diagnosis of DHPR deficiency in one family. This di...

Characterization of quinonoid-dihydropteridine reductase (QDPR) from the lower eukaryote Leishmania major.

Biopterin is required for growth of the protozoan parasite Leishmania and is salvaged from the host through the activities of a novel biopterin transporter (BT1) and broad-spectrum pteridine reductase (PTR1). Here we characterize Leishmania major quinonoid-dihydropteridine reductase (LmQDPR), the key enzyme required for regeneration and maintenance of H(4)biopterin pools. LmQDPR shows good homo...

Atypical PKU with normal phenylalanine hydroxylase and dihydropteridine reductase activity in vitro.