THE ENZYME OF DIHYDROPTERIDINE REDUCTASE (DHPR) AND ITS CLINICAL IMPORTANCE

Zeynep ALTINDAG*, Gönül SAHIN*,o

*Hacettepe University, Faculty of Pharmacy, Department of Pharmaceutical Toksicology 06100 Sihhiye, Ankara, TURKEY.
oCorresponding Author

Summary:
Dihydropteridine reductase is a key enzyme in the cycle of pteridines, which have important cofactor roles in various biochemical events. This enzyme, which has a dimeric structure with two identical peptide chains, keeps the level of tetrahydrobiopterin (BH4) by reducing quinonoid dihydrobiopterin (q-BH2), which forms during the hydroxylation reactions of monoamine transmitters and therefore maintains their synthesis. It has been suggested that the activity of enzyme, changes in many neurologic or metabolic disorders. Some of the xenobiotics may exert the neurotoxicity by affecting the activity of the enzyme.

Key words:
Dihydropteridine reductase, Tetrahydrobiopterin, Quinonoid dihydrobioptein, Monoamine transmitters, Neurotoxicity