Tetrahydrofolic acid (THF) is an important biochemical intermediate that plays a crucial role in reactions involving the addition of a single carbon atom, such as the synthesis of the purine ring system and the introduction of the methyl group into thymidylate.

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.

2020年9月6日 · Tetrahydrofolate (THF) or tetrahydrofolic acid is a derivative of vitamin B9 (folic acid or pteroyl-L-glutamic acid). This water-soluble vitamin is a coenzyme for metabolic reactions involving amino acid and nucleic acid formations.

1. 叶酸被二氢叶酸还原酶 (DHFR) 还原为二氢叶酸 (DHF)，然后再还原为四氢叶酸 (tetrahydrofolate, THF)。 2. THF 可用于嘌呤合成，通过使用甲酸盐作为一碳供体转化为 10-甲酰基 THF。或者，可以使用丝氨酸作为一碳供体，以维生素 B6 作为辅助因子将 THF 转化为 5,10-亚甲 …

DHF, THF, and 10-formyl-THF are efficient substrates for FPGS, whereas 5-methyl-THF, 5-formyl-THF, and folic acid are poor substrates (Cichowicz and Shane, 1987). Because 5-methyl-THF is the major circulating folate, its conversion by methionine synthase (MTR) to THF is thought to be the first metabolic step in cells that precedes ...

Dihydrofolate reductase (DHFR) catalyzes the reduction of dihydrofolate to tetrahydrofolate (THF). THF is needed for the action of folate-dependent enzymes and is thus essential for DNA synthesis and methylation.

One carbon metabolism or the folate cycle utilizes four enzymes, dihydrofolate reductase (DHFR), serine hydroxymethyltransferase-1 (SHMT1), and methylenetetrahydrofolate Dehydrogenase (NADP + Dependent) 1 (MTHFD1) resulting in various tetrahydrofolate (THF) species, such as, 5, 10-CH 2-THF and 10-formyl-THF. 5, 10-CH 2-THF is used in ...

2019年4月5日 · DHP is further converted to dihydrofolate (DHF) in the reaction mediated by dihydrofolate synthetase (DHFS), which attaches the first glutamate residue to the carboxyl moiety of pABA in DHP (Fig....

二氢叶酸还原酶，或称DHFR，是一种将二氢叶酸还原为四氢叶酸的酶，使用NADPH作为电子供体，可以转化为1-碳转移化学中使用的四氢叶酸辅因子。 在人类中，DHFR酶由 DHFR 吉恩。 [1][2] DHFR 基因位于5号染色体q11→q22区域。 [3] 不同的细菌种类拥有不同的DHFR酶 (基于它们结合二氨基杂环分子的模式)，但是哺乳动物中的DHFR酶高度相似。 [4] 中心的八股β折叠片是DHFR多肽链折叠的主要特征。 [5] 其中七股折叠片是平行的，第八股是反平行的。 四个α螺旋连接连 …

2014年1月1日 · Folate species DHF and THF do not play a direct role in metabolism, but receive one-carbon moieties and transfer them toward either methylation or DNA-synthesis pathways. Methotrexate is a competitive and irreversible inhibitor of the enzyme DHF reductase which converts folic acid and DHF to THF, and thus inhibits both nucleotide biosynthesis ...