What is THFA (tetrahydrofolic acid)?
Tetrahydrofolic acid ( THFA ), or tetrahydrofolate, is a folic acid derivative. Tetrahydrofolic acid is produced from dihydrofolic acid by dihydrofolate reductase. This reaction is inhibited by methotrexate. It is converted into 5,10-methylenetetrahydrofolate by serine hydroxymethyltransferase .
How do tetrahydrofolates (THF) work?
The functioning of tetrahydrofolates (THF) in oxidation and reduction of single-carbon fragments. A PLP-dependent enzyme cleaves serine ( Fig. 14 ), releasing formaldehyde, which combines in the active center with THF. Formic acid can be converted to formyl-THF.
What does THFA stand for?
Tetrahydrofolic acid ( THFA ), or tetrahydrofolate, is a folic acid derivative. Tetrahydrofolic acid is produced from dihydrofolic acid by dihydrofolate reductase. This reaction is inhibited by methotrexate. It is converted into 5,10-methylenetetrahydrofolate by serine hydroxymethyltransferase .
What is the difference between THF and vitamin B9?
Tetrahydrofolate (THF) or tetrahydrofolic acid is a derivative of Vitamin B9 (folic acid or pteroyl-L-glutamic acid), a water-soluble vitamin that serves as a coenzyme for metabolic reactions involving amino acids and nucleic acids.
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Is tetrahydrofolate a coenzyme or cofactor?
Tetrahydrofolate or tetrahydrofolic acid is a folic acid derivative that serves as a coenzyme for metabolic reactions involving amino acids and nucleic acids [578].
What is the importance of THF?
THF is widely used as a solvent for special resins such as photosensitive resins, because even at room temperature it can dissolve various resins, and it is miscible with water and most organic solvents. In, addition, it is used as a solvent for Grignard and Wittig reactions.
Is THF the same as folate?
Folate and folic acid are terms that identify vitamin B9. Folate actually refers to the tetrahydrofolate (THF) derivative found naturally in fresh fruits, vegetables and beans. Folate is a natural product.
Is THF required for DNA-synthesis?
THF is required for the synthesis of DNA bases (purines and pyrimidines)1. As shown in the link below, N10-formyl-THF (a form of THF) is needed in 2 reactions (3 and 9) in purine synthesis.
Is THF a strong base?
Tetrahydrofuran (or THF), a mild Lewis base, is a colourless liquid.
What kind of solvent is THF?
It is an aprotic solvent with a dielectric constant of 7.6. It is a moderately polar solvent and can dissolve a wide range of nonpolar and polar chemical compounds. THF is water-miscible and can form solid clathrate hydrate structures with water at low temperatures.
How is folic acid converted to THF?
Folic acid itself has no coenzyme activity until it is reduced to THF by a two-step enzymatic reaction involving a DHF intermediate and the DHFR (Blakley, 1984).
What is THF in biochemistry?
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.
Which is the coenzyme form of folic acid?
tetrahydrofolic acidThe vitamin, folic acid, is converted to its coenzyme form, tetrahydrofolic acid, by a pyridine nucleotide-dependent enzyme, dihydrofolate reductase.
Why is folate important for DNA synthesis?
Folate has a dominant role in DNA metabolism, function, and repair due to its ability to methylate cytosine, thereby controlling gene expression, and its key function in nucleotide synthesis. Folate deficiency leads to genomic instability and genomic instability appears through two latent pathways (Fig. 1).
Why folate is required for DNA synthesis?
Folate, as 5,10 methylene THF, donates a methyl group to uracil converting it to thymine, which is used for DNA synthesis and repair. However, if folate is limiting, uracil misincorporation into DNA may occur. This in itself is mutagenic, but DNA instability also may occur via a different mechanism.
Which derivative of tetrahydrofolate is involved in the purine ring synthesis?
5,10-methylene-THFIn particular, 5,10-methylene-THF is essential for the synthesis of purines and pyrimidines and therefore ultimately for nucleotide, DNA, and RNA synthesis and, therefore, genetic function.
What is THF in organic chemistry?
Tetrahydrofuran (THF, oxolane) is a versatile solvent used in laboratory organic synthesis and in industrial products such as varnishes. It is colorless and miscible in water, with a boiling point of 66 ºC. It is highly flammable but relatively nontoxic.
What is the THF enzyme?
THF is an enzymatic co-factor which is involved in the biosynthesis of various biologically important molecules including purine and pyrimidine nucleotides (the building blocks of DNA and RNA) and several amino acids including methionine and glycine.
What is the cause of megaloblastic anemia?
Deficiencies of vitamin B12 and folic acid are the leading causes of megaloblastic anemia. Folic acid is present in food such as green vegetables, fruits, meat, and liver.
Why is glutamate used in Transamination?
First, through the well-described transdeamination system involving aminotransferases and glutamate dehydrogenase, glutamate plays a key catalytic role in the removal of α-amino nitrogen from amino acids.
How is THF synthesized?
Although crucial to both humans and Plasmodia, the route by which THF is synthesized varies greatly between the two species. While humans are dependent on a dietary intake of folic acid (which is reduced to THF by the enzyme dihydrofolate reductase ), Plasmodia can synthesize THF from smaller precursors via a de novo pathway ( Fig. 5.2 ). Through the actions of several enzymes, guanosine triphosphate (GTP) is converted to 6-hydroxymethyl-7,8-dihydropterinpyrophosphate (DHPP). The enzyme dihydropteroate synthase (DHPS) subsequently catalyzes the coupling of p -aminobenzoic acid ( p ABA) and DHPP to form 7,8-dihydropteroate (DHP). Dihydrofolate synthase (DHFS) adds a glutamate moiety to form 7,8-dihydrofolate (DHF), then dihydrofolate reductase (DHFR) reduces DHF to THF with the accompanying oxidation of NADPH. As shown, THF is subsequently metabolized back to DHF by the action of several enzymes-a process which leads to the generation of the pyrimidine nucleotide thymidine monophosphate (dTMP) and the amino acids glycine and methionine. In addition to synthesizing THF via the preceding pathway, Plasmodium falciparum can utilize exogenous DHF via a salvage pathway. 1-3
Which vitamin is the third one carbon carrier?
Both of these are important intermediates in a variety of biosynthetic processes. The third one-carbon carrier is vitamin B 12 which can act as an acceptor, taking the methyl group from methyl-THF to form methylcobalamin (Fig. 7).
What is the difference between acetyl-coa and malonyl-coa?
In the biosynthetic pathway, acetyl-CoA is first converted to malonyl-CoA which undergoes decarboxylation when a two-carbon unit is added to the growing fatty acid chain. This decarboxylation, together with the prior carboxylation steps, couples ATP cleavage to the biosynthesis.
Which coenzyme has a three carbon side chain that carries two hydroxyl groups?
Another, called biopterin, has a three-carbon side chain that carries two hydroxyl groups. Its reduced form, tetrahydrobiopterin, is a coenzyme for a series of hydroxylases. Among these is phenylalanine hydroxylase which is lacking in the well-known human genetic defect phenylketonuria (PKU).
Is DHFR present in humans?
To date, inhibitors of both DHPS and DHFR have been developed as antimalarial agents. Whereas DHPS is absent in humans, DHFR is present in both humans and Plasmodia. However, there are sufficient differences between human and Plasmodia DHFR enzymes to allow the development of species-selective inhibitors.
What are the functions of THF?
There are 2 major cofactor functions of THF 1: 1. DNA Synthesis. THF is required for the synthesis of DNA bases (purines and pyrimidines) 1. As shown in the link below, N10-formyl-THF (a form of THF) is needed in 2 reactions (3 and 9) in purine synthesis.
What is THF in amino acid metabolism?
Web Link. 2. Amino Acid Metabolism. THF is a cofactor for enzymes that metabolize histidine, serine, glycine, and methionine 1. The following link shows that THF is a cofactor for serine hydroxymethyltransferase, the enzyme that converts serine to glycine.
What is 6R-5,10-methylene-THF?
[6R]-5,10-methylene-THF is a biomodulator that has proven to enhance the desired cytotoxic antitumor effect of Fluorouracil (5-FU) and can bypass the metabolic pathway required by other folates (such as leucovorin) to achieve necessary activation. The active metabolite is being evaluated in clinical trials for patients with colorectal cancer in combination with 5-FU.
What is methyltetrahydrofolate?
Methylenetetrahydrofolate is an intermediate in the detoxification of formaldehyde.
What is a T/F protein?
T/F Complementary proteins are two incomplete proteins that have the same limiting amino acid (s), thus combining them together they compensate for the limiting amino acids in the other food.
Why is T/F sugar not good for gum?
True. T/F Sugar alcohols are not a good option for chewing gum because they are readily fermented by bacteria in the mouth.
How are the 3 fatty acids processed?
Explain how the 3 fatty acids would be 1) processed in the enterocyte (if applicable); 2) absorbed; 3) transported after absorption. Long chain fatty acids will be re-esterified into triglycerides, phospholipids, and cholesterol esters, which will be packaged into chylomicrons. No processing of SCFA and MCFA.
Where is T/F bile stored?
T/F Bile, which is produced by the gall bladder and stored in the liver, emulsifies fat in the stomach.
Is T/F similar to sucrose?
T/F Saccharine is similar in structure to sucrose, the only difference being chlorines that replace alcohols.
