性做久久久久久坡多野结衣-性做久久久久久久久浪潮-性欲影院-性影院-国产精品线路一线路二-国产精品兄妹在线观看麻豆

Dihydrofolate reductase, or DHFR, is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, using NADPH as an electron donor, which can be converted to the kinds of tetrahydrofolate cofactors used in one-carbon transfer chemistry. DHFR mutations cause dihydrofolate reductase deficiency, a rare autosomal recessive inborn error of folate metabolism that results in megaloblastic anemia, pancytopenia and severe cerebral folate deficiency. These issues can be overcome by supplementation with a reduced form of folate, usually folinic acid. DHFR is an attractive pharmaceutical target for inhibition due to its pivotal role in DNA precursor （thymine） synthesis. Trimethoprim, an antibiotic, inhibits bacterial DHFR while methotrexate, a chemotherapy agent, inhibits mammalian DHFR.