Tetrahydrofolate dehydrogenase/Definition

An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. Also known as dihydrofolate dehydrogenase, dihydrofolate reductase and folic acid reductase; differs from methylenetetrahydrofolate reductase