Compounds based on 5,6,7,8-tetrahydrofolate.

Kinetic profile of overall elimination of 5-methyltetrahydropteroylglutamate in rats. (1/526)

The in vivo biliary and urinary excretion kinetics of 5-methyltetrahydropteroylglutamate (5-CH3-H4PteGlu) were studied in rats. During infusion at various rates (48-965 nmol. h-1. kg-1), the total body clearance (CLtotal) of 5-CH3-H4PteGlu could be attributed almost entirely to the sum of the biliary and urinary (CLurine,p) excretion clearances. After a 4-h infusion at the highest rate, the 5-CH3-H4PteGlu in the liver was 10 times higher than the endogenous level, whereas its polyglutamate form did not increase, suggesting that most of the infused 5-CH3-H4PteGlu is not incorporated in the polyglutamate pool but is eliminated by excretion. The parallel increase in CLtotal and CLurine,p with the increase in infusion rate might result from saturation of reabsorption at the renal proximal tubules, since the urinary excretion clearance, defined with respect to the kidney concentration, also increased while the biliary excretion clearance, defined with respect to the liver concentration, remained almost constant. We conclude that the hepatobiliary excretion is a relatively low-affinity process with a constant clearance, whereas the renal tubular reabsorption is saturated at higher plasma 5-CH3-H4PteGlu concentration ( approximately 0.5 microM). Urinary excretion becomes the predominant elimination route for any excess 5-CH3-H4PteGlu in the body.  (+info)

Control of expression of one-carbon metabolism genes of Saccharomyces cerevisiae is mediated by a tetrahydrofolate-responsive protein binding to a glycine regulatory region including a core 5'-CTTCTT-3' motif. (2/526)

Expression of yeast genes involved in one-carbon metabolism is controlled by glycine, by L-methionine, and by nitrogen sources. Here we report a novel control element containing a core CTTCTT motif mediating the glycine response, demonstrating that a protein binds this element, that binding is modulated by tetrahydrofolate, and that folate is required for the in vivo glycine response. In an heterologous CYC1 promoter the region needed for the glycine response of GCV2 (encoding the P-subunit of glycine decarboxylase) mediated repression that was relieved by glycine. It was also responsible for L-methionine control but not nitrogen repression. GCV1 and GCV3 have an homologous region in their promoters. The GCV1 region conferred a glycine response on an heterologous promoter acting as a repressor or activator depending on promoter context. A protein was identified that bound to the glycine regulatory regions of GCV1 and GCV2 only if the CTTCTT motif was intact. This protein protected a 17-base pair CATCN7CTTCTT region of GCV2 that is conserved between GCV1 and GCV2. Protein binding was increased by tetrahydrofolate, and use of a fol1 deletion mutant indicated the involvement of a folate in the in vivo glycine response. Tetrahydrofolate or a derivative may act as a ligand for the transcription factor controlling expression of one-carbon metabolism genes.  (+info)

The energy conserving methyltetrahydromethanopterin:coenzyme M methyltransferase complex from methanogenic archaea: function of the subunit MtrH. (3/526)

In methanogenic archaea the transfer of the methyl group of N5-methyltetrahydromethanopterin to coenzyme M is coupled with energy conservation. The reaction is catalyzed by a membrane associated multienzyme complex composed of eight different subunits MtrA-H. The 23 kDa subunit MtrA harbors a corrinoid prosthetic group which is methylated and demethylated in the catalytic cycle. We report here that the 34 kDa subunit MtrH catalyzes the methylation reaction. MtrH was purified and shown to exhibit methyltetrahydromethanopterin:cob(I)alamin methyltransferase activity. Sequence comparison revealed similarity of MtrH with MetH from Escherichia coli and AcsE from Clostridium thermoaceticum: both enzymes exhibit methyltetrahydrofolate:cob(I)alamin methyltransferase activity.  (+info)

Folate and homocysteine metabolism in copper-deficient rats. (4/526)

To investigate the effect of copper deficiency on folate and homocysteine metabolism, we measured plasma, red-cell and hepatic folate, plasma homocysteine and vitamin B-12 concentrations, and hepatic methionine synthase activities in rats. Two groups of male Sprague-Dawley rats were fed semi-purified diets containing either 0. 1 mg (copper-deficient group) or 9.2 mg (control group) of copper per kg. After 6 weeks of dietary treatment, copper deficiency was established as evidenced by markedly decreased plasma and hepatic copper concentrations in rats fed the low-copper diet. Plasma, red-cell, hepatic folate, and plasma vitamin B-12 concentrations were similar in both groups, whereas plasma homocysteine concentrations in the copper-deficient group were significantly higher than in the control group (P<0.05). Copper deficiency resulted in a 21% reduction in hepatic methionine synthase activity as compared to the control group (P<0.01). This change most likely caused the increased hepatic 5-methyltetrahydrofolate and plasma homocysteine concentrations in the copper-deficient group. Our results indicate that hepatic methionine synthase may be a cuproenzyme, and plasma homocysteine concentrations are influenced by copper nutriture in rats. These data support the concept that copper deficiency can be a risk factor for cardiovascular disease.  (+info)

The crystal structure of a bacterial, bifunctional 5,10 methylene-tetrahydrofolate dehydrogenase/cyclohydrolase. (5/526)

The structure of a bifunctional 5,10-methylene-tetrahydrofolate dehydrogenase/cyclohydrolase from Escherichia coli has been determined at 2.5 A resolution in the absence of bound substrates and compared to the NADP-bound structure of the homologous enzyme domains from a trifunctional human synthetase enzyme. Superposition of these structures allows the identification of a highly conserved cluster of basic residues that are appropriately positioned to serve as a binding site for the poly-gamma-glutamyl tail of the tetrahydrofolate substrate. Modeling studies and molecular dynamic simulations of bound methylene-tetrahydrofolate and NADP shows that this binding site would allow interaction of the nicotinamide and pterin rings in the dehydrogenase active site. Comparison of these enzymes also indicates differences between their active sites that might allow the development of inhibitors specific to the bacterial target.  (+info)

The amino-terminal region of the Escherichia coli T-protein of the glycine cleavage system is essential for proper association with H-protein. (6/526)

T-protein is a component of the glycine cleavage system and catalyzes the tetrahydrofolate-dependent reaction. Our previous work on Escherichia coli T-protein (ET) showed that the lack of the N-terminal 16 residues caused a loss of catalytic activity [Okamura-Ikeda, K., Ohmura, Y., Fujiwara, K. and Motokawa, Y. (1993) Eur. J. Biochem. 216, 539-548]. To define the role of the N-terminal region of ET, a series of deletion mutants were constructed by site-directed mutagenesis and expressed in E. coli. Deletions of the N-terminal 4, 7 and 11 residues led to reduction in the activity to 42, 9 and 4%, respectively, relative to the wild-type enzyme (wtET). The mutant with 7-residue deletion (ETDelta7) was purified and analyzed. ETDelta7 exhibited a marked increase in Km (25-fold) for E. coli H-protein (EH) accompanied by a 10-fold decrease in kcat compared with wtET, indicating the importance of the N-terminal region in the interaction with EH. The role of this region in the ET-EH interaction was investigated by cross-linking of wtET-EH or ETDelta7-EH complex with 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, a zero-length cross-linker, in the presence of folate substrates. The resulting tripartite cross-linked products were cleaved with lysylendopeptidase and V8 protease. After purification by reversed-phase HPLC, the cross-linked peptides were subjected to Edman sequencing. An intramolecular cross-linking between Asp34 and Lys216 of wtET which was not observed in wtET alone and an intermolecular cross-linking between Lys288 of wtET and Asp-43 of EH were identified. In contrast, no such cross-linking was detected from the cross-linked product of ETDelta7. These results suggest that EH, when it interacts with ET, causes a change in conformation of ET and that the N-terminal region of ET is essential for the conformational change leading to the proper interaction with EH.  (+info)

Bioactivity of orally administered unnatural isomers, [6R]-5-formyltetrahydrofolate and [6S]-5,10-methenyltetrahydrofolate, in humans. (7/526)

It has been assumed that humans cannot utilize 5,6,7,8-tetrahydrofolates with the unnatural configuration at carbon 6, since these folates are enzymatically and microbiologically inactive. We hypothesized that orally administered unnatural [6R]-5-formyltetrahydrofolate or [6S]-5,10-methenyltetrahydrofolate is bioactive in humans. Subjects were given independent oral doses of these unnatural folates and of a natural [6S]-5-formyltetrahydrofolate. Plasma, before and after the dose for 4 h, and 2 h urine were collected. Areas under the curve for the change in plasma folate concentrations were measured microbiologically and urinary folates were measured using HPLC. Based on findings of plasma and urinary folates, the unnatural folates were estimated to be 14-50% active as compared to [6S]-5-formyltetrahydrofolate. The major plasma and urinary folate was [6S]-5-methyltetrahydrofolate in all experiments. In urine, a [6S]-5-formyltetrahydrofolate peak was observed only after a [6S]-5-HCO-H4folate dose and peaks of unnatural [6S]-10-formyltetrahydrofolate and 5-formyltetrahydrofolate were identified after a [6R]-5-formyltetrahydrofolate dose. A possible pathway that explains our findings is discussed. This pathway includes the oxidation of the unnatural [6S]-10-formyltetrahydrofolate to 10-formyl-7,8-dihydrofolate which can be further metabolized by 5-amino-4-imidazolecarboxamide-ribotide transformylase producing dihydrofolate. Dihydrofolate can then be metabolized to [6S]-5-methyltetrahydrofolate by well-established metabolism.  (+info)

Effective correction of hyperhomocysteinemia in hemodialysis patients by intravenous folinic acid and pyridoxine therapy. (8/526)

Effective correction of hyperhomocysteinemia in hemodialysis patients by intravenous folinic acid and pyridoxine therapy. BACKGROUND: Folic acid supplementation is only partially efficacious in correcting moderate elevation of plasma total homocysteine (tHcy) concentrations observed in hemodialysis (HD) patients. Experimental and clinical data have suggested that this partial efficacy may be due to impairment of folic acid metabolism to 5-methyltetrahydrofolate (MTHF) and of MTHF transmembrane transport as well. To bypass these difficulties, we assessed the efficacy of intravenous (i.v.) folinic acid, a ready precursor of MTHF, on reducing plasma tHcy concentrations in HD patients. METHODS: In a cohort of 37 patients on intermittent HD treatment, plasma tHcy concentrations were determined before and during i.v. supplementation of folinic acid (50 mg once per week), together with i.v. pyridoxine (250 mg 3 times per week), to prevent vitamin deficiency, particularly in those treated by recombinant erythropoietin. RESULTS: Folinic acid and pyridoxine i.v. supplementation was given for 11.2 +/- 2.45 months (range 7.5 to 17 months). The mean plasma tHcy levels decreased significantly from 37. 3 +/- 5.8 microM at baseline to 12.3 +/- 5.4 microM on folinic acid treatment (P < 0.001). Moreover, 29 of the 37 patients (78%) had normal plasma tHcy levels at the end of follow-up (that is, <14.1 microM, mean 9.8 microM, range 6.2 to 13 microM). No adverse effects attributable to folinic acid treatment were observed during this time. CONCLUSIONS: Intravenous folinic acid therapy (50 mg) once per week associated with pyridoxine supplementation appears to be an effective and safe strategy to normalize plasma tHcy levels in the majority of chronic HD patients.  (+info)

Tetrahydrofolates (THFs) are a type of folate, which is a form of vitamin B9. Folate is essential for the production and maintenance of new cells, especially in DNA synthesis and methylation. THFs are the active forms of folate in the body and are involved in various metabolic processes, including:

1. The conversion of homocysteine to methionine, an amino acid required for protein synthesis and the formation of S-adenosylmethionine (SAM), a major methyl donor in the body.
2. The transfer of one-carbon units in various metabolic reactions, such as the synthesis of purines and pyrimidines, which are essential components of DNA and RNA.
3. The remethylation of homocysteine to methionine, a process that helps maintain normal homocysteine levels in the body. Elevated homocysteine levels have been linked to an increased risk of cardiovascular disease.

THFs can be obtained from dietary sources, such as leafy green vegetables, legumes, and fortified cereals. They can also be synthesized endogenously in the body through the action of the enzyme dihydrofolate reductase (DHFR), which reduces dihydrofolate (DHF) to THF using NADPH as a cofactor.

Deficiencies in folate or impaired THF metabolism can lead to various health issues, including megaloblastic anemia, neural tube defects during fetal development, and an increased risk of cardiovascular disease due to elevated homocysteine levels.

... es are a class of homologous RNAs in certain bacteria that bind tetrahydrofolate (THF). It is almost ... The 3-d structure of the tetrahydrofolate riboswitch has been solved by separate groups using X-ray crystallography. These ... Trausch JJ, Ceres P, Reyes FE, Batey RT (October 2011). "The structure of a tetrahydrofolate-sensing riboswitch reveals two ... "A eubacterial riboswitch class that senses the coenzyme tetrahydrofolate". Chem. Biol. 17 (7): 681-685. doi:10.1016/j.chembiol. ...
In enzymology, a tetrahydrofolate synthase (EC 6.3.2.17) is an enzyme that catalyzes the chemical reaction ATP + ... R Rebeille F; Cherest, H; Jabrin, S; Grunwald, D; Surdin-Kerjan, Y; Douce, R; Rébeillé, F (2001). "Tetrahydrofolate ...
... and tetrahydrofolate formylase. Human genes encoding formate-tetrahydrofolate ligases include: MTHFD1 - cytoplasmic MTHFD1L - ... I. The tetrahydrofolate formylase from pigeon liver. Purification and mechanism.]". Biochem. Z. 334: 108-32. PMID 13789141. ... The systematic name of this enzyme class is formate:tetrahydrofolate ligase (ADP-forming). Other names in common use include: ... In enzymology, a formate-tetrahydrofolate ligase (EC 6.3.4.3) is an enzyme that catalyzes the chemical reaction ATP + formate ...
In enzymology, a trimethylsulfonium-tetrahydrofolate N-methyltransferase (EC 2.1.1.19) is an enzyme that catalyzes the chemical ... The systematic name of this enzyme class is trimethylsulfonium:tetrahydrofolate N-methyltransferase. This enzyme is also called ... Wagner C, Lusty SM, Kung HF, Rogers NL (1967). "Preparation and properties of trimethylsulfonium-tetrahydrofolate ... the two substrates of this enzyme are trimethylsulfonium and tetrahydrofolate, whereas its two products are dimethyl sulfide ...
Found in all organisms, DHFR has a critical role in regulating the amount of tetrahydrofolate in the cell. Tetrahydrofolate and ... DHFR is responsible for the levels of tetrahydrofolate in a cell, and the inhibition of DHFR can limit the growth and ... In the end, dihydrofolate is reduced to tetrahydrofolate and NADPH is oxidized to NADP+. The high flexibility of Met20 and ... Miszta H, Dabrowski Z, Lanotte M (November 1988). "In vitro patterns of enzymic tetrahydrofolate dehydrogenase (EC 1.5.1.3) ...
... reductase (MTRR) or methylene-tetrahydrofolate reductase (MTHFR) deficiencies can also result in the ... December 2012). "Mechanism-based design, synthesis and biological studies of N⁵-substituted tetrahydrofolate analogs as ... yielding tetrahydrofolate (THF) and methionine. Methionine synthase is the only mammalian enzyme that metabolizes N5-MeTHF to ... yielding tetrahydrofolate (THF) and regenerating the methylcoalamin form of the enzyme. Under physiological conditions, ...
In the cell, L-methylfolate is used in the methylation of homocysteine to form methionine and tetrahydrofolate (THF). THF is ... It is a methylated derivative of tetrahydrofolate. Levomefolic acid is generated by methylenetetrahydrofolate reductase (MTHFR ...
Monofunctional C1-tetrahydrofolate synthase, mitochondrial also known as formyltetrahydrofolate synthetase, is an enzyme that ... Sugiura T, Nagano Y, Inoue T, Hirotani K (2004). "A novel mitochondrial C1-tetrahydrofolate synthetase is upregulated in human ... Prasannan P, Pike S, Peng K, Shane B, Appling DR (October 2003). "Human mitochondrial C1-tetrahydrofolate synthase: gene ... Fountoulakis M, Gulesserian T, Lubec G (2003). "Overexpression of C1-tetrahydrofolate synthase in fetal Down syndrome brain". J ...
"Entrez Gene: MTHFR methylene tetrahydrofolate reductase (NAD(P)H)". Födinger M, Hörl WH, Sunder-Plassmann G (2000). "Molecular ... Iqbal MP, Frossard PM (January 2003). "Methylene tetrahydrofolate reductase gene and coronary artery disease". The Journal of ... 10-methylene tetrahydrofolate is used to convert dUMP to dTMP for de novo thymidine synthesis. 5-Methyltetrahydrofolate is used ...
... is a methyltransferase enzyme which uses tetrahydrofolate as part of histidine catabolism. It ... tetrahydrofolate + N-formyl-L-glutamate It is classified under EC 2.1.2.5 and in mammals is found as part of a bifunctional ... catalyses two reactions: 5-formimidoyltetrahydrofolate + L-glutamate <=> tetrahydrofolate + N-formimidoyl-L-glutamate 5- ...
It binds dihydrofolate reductase and prevents synthesis of tetrahydrofolate. It is used in the treatment of autoimmune diseases ...
Tetrahydrofolate riboswitches bind tetrahydrofolate to regulate synthesis and transport genes. TPP riboswitches (also THI-box) ...
... tetrahydrofolate-dependent self-inactivation by 5-FdUMP". Archives of Biochemistry and Biophysics. 674: 108106. doi:10.1016/j. ...
... is a member of the tetrahydrofolate dehydrogenase/cyclohydrolase family. This enzyme is expressed in all adult tissues ...
5-methyl tetrahydrofolate provides a methyl group, which is released to the reaction with homocysteine, resulting in methionine ... The creation of 5-methyl tetrahydrofolate is an irreversible reaction. If B12 is absent, the forward reaction of homocysteine ... to methionine does not occur, homocysteine concentrations increase, and the replenishment of tetrahydrofolate stops. Because ...
Tetrahydrofolate gets this extra carbon atom by sequestering formaldehyde produced in other processes. These single-carbon ... PMID 5881255.[permanent dead link] Tetrahydrofolate bound to proteins in the PDB (All articles with dead external links, ... Tetrahydrofolic acid (THFA), or tetrahydrofolate, is a folic acid derivative. Tetrahydrofolic acid is produced from ... as an inhibitor and thus reduces the amount of tetrahydrofolate made. This may result in megaloblastic anemia. Tetrahydrofolic ...
Its binding affinity for dihydrofolate reductase effectively blocks tetrahydrofolate synthesis. This results in the depletion ...
The glyA and folD convert between other one-carbon adducts of tetrahydrofolate. Another gene commonly associated with pfl RNAs ... Most obviously, for example, formate-tetrahydrofolate ligase synthesizes 10-formyltetrahydrofolate. ... purine derivatives can be used to regulate one-carbon metabolism by indirectly sensing a shortage of 10-formyl-tetrahydrofolate ...
DHFR catalyses the conversion of dihydrofolate to the active tetrahydrofolate. Tetrahydrofolate is needed for the de novo ... an enzyme that participates in the tetrahydrofolate synthesis. The affinity of methotrexate for DHFR is about 1000-fold that of ...
Peri KG, Belanger C, Mackenzie RE (Dec 1989). "Nucleotide sequence of the human NAD-dependent methylene tetrahydrofolate ...
C-1-tetrahydrofolate synthase, cytoplasmic also known as C1-THF synthase is an enzyme that in humans is encoded by the MTHFD1 ( ... Overview of all the structural information available in the PDB for UniProt: P11586 (C-1-tetrahydrofolate synthase, cytoplasmic ... Peri KG, Belanger C, Mackenzie RE (November 1989). "Nucleotide sequence of the human NAD-dependent methylene tetrahydrofolate ... and formate-tetrahydrofolate ligase (6.3.4.3). Each of these activities catalyzes one of three sequential reactions in the ...
Tetrahydrofolate's main function in metabolism is transporting single-carbon groups (i.e., a methyl group, methylene group, or ... Alternative carbon sources include formate which by the catalytic action of formate-tetrahydrofolate ligase add a 1C unit to ... Folic acid is first reduced to dihydrofolate and then to tetrahydrofolate. Each step consumes one molecule of NADPH ( ... A one-carbon (1C) methyl group is added to tetrahydrofolate through the action of serine hydroxymethyltransferase (SHMT) to ...
folE RNAs have been shown to bind tetrahydrofolate and related molecules, leading to their designation as a second structural ... Chen X, Mirihana Arachchilage G, Breaker RR (September 2019). "Biochemical validation of a second class of tetrahydrofolate ... class of tetrahydrofolate riboswitches, called THF-II riboswitches. Weinberg Z, Lünse CE, Corbino KA, Ames TD, Nelson JW, Roth ...
Methotrexate inhibits dihydrofolate reductase (DHFR), an enzyme that regenerates tetrahydrofolate from dihydrofolate. When the ...
Other names in common use include 10-formyl tetrahydrofolate:NADP oxidoreductase, 10-formyl-H2PtGlu:NADP oxidoreductase, 10- ... Kutzbach C, Stokstad EL (1968). "Partial purification of a 10-formyl-tetrahydrofolate: NADP oxidoreductase from mammalian liver ... tetrahydrofolate + CO2 + NADPH + H+ The 3 substrates of this enzyme are 10-formyltetrahydrofolate, NADP+, and H2O, whereas its ... 4 products are tetrahydrofolate, CO2, NADPH, and H+. This enzyme belongs to the family of oxidoreductases, to be specific those ...
Any folic acid that is not converted to tetrahydrofolate in the liver remains in the blood until it is either metabolized in ... Folic acid is absorbed and transported in the bloodstream to the liver, where it is converted to tetrahydrofolate, a second ... The liver has a limited capacity to metabolize folic acid into tetrahydrofolate. ...
When coupled with C1-tetrahydrofolate synthase and tetrahydropteroate, cSHMT also catalyzes the conversion of formate to serine ... Schirch L, Quashnock J (June 1981). "Evidence that tetrahydrofolate does not bind to serine hydroxymethyltransferase with ... simultaneous conversions of L-serine to glycine and tetrahydrofolate (THF) to 5,10-Methylenetetrahydrofolate (5,10-CH2-THF). ... coli serine hydroxymethyltransferase in complex with glycine substrate and 5-formyl tetrahydrofolate". Journal of Molecular ...
Inhibition of DHFR prevents the parasite from recycling dihydrofolate back to tetrahydrofolate (THF). THF is required for DNA ...
"A methenyl tetrahydromethanopterin cyclohydrolase and a methenyl tetrahydrofolate cyclohydrolase in Methylobacterium extorquens ...
8* The most important methyl donor for DNA methylation is 5-methyl-tetrahydrofolate. Consequently, any changes in folate levels ... codes for the enzyme methylenetetrahydrofolate reductase which is necessary for the synthesis of 5-methyl-tetrahydrofolate, a ...
Tetrahydrofolate riboswitches are a class of homologous RNAs in certain bacteria that bind tetrahydrofolate (THF). It is almost ... The 3-d structure of the tetrahydrofolate riboswitch has been solved by separate groups using X-ray crystallography. These ... Trausch JJ, Ceres P, Reyes FE, Batey RT (October 2011). "The structure of a tetrahydrofolate-sensing riboswitch reveals two ... "A eubacterial riboswitch class that senses the coenzyme tetrahydrofolate". Chem. Biol. 17 (7): 681-685. doi:10.1016/j.chembiol. ...
... complex with tetrahydrofolate. ...
5-formyl-tetrahydrofolate [5-formylTHF], tetrahydrofolate [THF], and 5,10-methenyl-tetrahydrofolate [5,10-methenylTHF]) were ... LBXSF1SI - 5-Methyl-tetrahydrofolate (nmol/L). Variable Name: LBXSF1SI. SAS Label: 5-Methyl-tetrahydrofolate (nmol/L). English ... LBDSF1LC - 5-Methyl-tetrahydrofolate cmt. Variable Name: LBDSF1LC. SAS Label: 5-Methyl-tetrahydrofolate cmt. English Text: 5- ... 5-Methyl-tetrahydrofolate (nmol/L). Target: Both males and females 1 YEARS - 150 YEARS. Code or Value. Value Description. Count ...
Tetrahydrofolate Impurity F with Purity 98.00% at Anax Laboratories. ...
5-formyl tetrahydrofolate. ¶ This branded product is no longer on the market. Generic alternatives may be available. ...
ChEBI tetrahydrofolate Enzyme Nomenclature 3-methyl-2-oxobutanoate hydroxymethyltransferase is,isDescribedBy,hasTaxon, ... Tetrahydrofolate (THF) and its one-carbon derivatives, collectively termed folates, are essential cofactors, but are inherently ... Tetrahydrofolate (THF) and its one-carbon derivatives, collectively termed folates, are essential cofactors, but are inherently ...
Methylene tetrahydrofolate reductase mutations. MTHFR mutations are a common cause for elevated levels of homocysteine, which ...
Fungal methionine synthase Met6p transfers a methyl group from 5-methyl-tetrahydrofolate to. * Post author By healthanddietblog ... Fungal methionine synthase Met6p transfers a methyl group from 5-methyl-tetrahydrofolate to homocysteine to create methionine. ...
... tetrahydrofolate; 5,10-CH3-THF, 5,10-CH3-tetrahydrofolate; 5-CH3-THF, 5-CH3-tetrahydrofolate. The arrows (. or ) indicate the ... methylene tetrahydrofolate reductase genotype, disease parameters and coronary risk factors," Journal of Tropical Pediatrics, ...
Methylene tetrahydrofolate Reductase Enzyme Level and Antioxidant Activity in Women with Gestational Hypertension and Pre- ... Methylene tetrahydrofolate Reductase Enzyme Level and Antioxidant Activity in Women with Gestational Hypertension and Pre- ... Methylene tetrahydrofolate Reductase Enzyme Level and Antioxidant Activity in Women with Gestational Hypertension and Pre- ... Osunkalu VO, Taiwo IA, Makwe CC, Akinsola OJ and Quao RA (2019). Methylene tetrahydrofolate Reductase Enzyme Level and ...
Formate--tetrahydrofolate ligase (FHS). Q7A535. 3.41 ↓. 2.75 ↓. 18. Phosphoenolpyruvate-protein phosphotransferase (PtsI). ...
This suggests that tetrahydrofolate cofactor depletion occurs only in S phase cells. The much larger drop in [3H]dUrd and 5- ... This suggests that tetrahydrofolate cofactor depletion occurs only in S phase cells. The much larger drop in [3H]dUrd and 5- ... This suggests that tetrahydrofolate cofactor depletion occurs only in S phase cells. The much larger drop in [3H]dUrd and 5- ... This suggests that tetrahydrofolate cofactor depletion occurs only in S phase cells. The much larger drop in [3H]dUrd and 5- ...
Genetic Variability of Methyl-Tetrahydrofolate-Reductase Modifies eNOS Coupling in Human Arteries and Veins: Effects on ... Genetic Variability of Methyl-Tetrahydrofolate-Reductase Modifies eNOS Coupling in Human Arteries and Veins: Effects on ...
5-Methyl-tetrahydrofolate acid improves endothelial function and decreases superoxide production by improving eNOS coupling and ... 5-Methyl-tetrahydrofolate acid improves endothelial function and decreases superoxide production by improving eNOS coupling and ...
Tetrahydrofolate Dehydrogenase / genetics * Thymidine Kinase / genetics * Transcription Factors / metabolism* * Transcriptional ...
10-methylene tetrahydrofolate; methyl-THF, N5-methyl tetrahydrofolate; SAH, S-adenosyl homocysteine; SAM, S-adenosyl methionine ... into tetrahydrofolate (THF). MethyL-THF is acquired from dietary folates which is converted from dihydrofolate (DHF) by ... dihydrofolate reductase (DHFR) and 5,10- methylenetetrahydrofolate (5,10MTHF) by methylene tetrahydrofolate reductase (MTHFR). ...
5-Methyl-tetrahydrofolate in prevention of recurrent preeclampsia. J Matern Fetal Neonatal Med2016;29:916-20. doi:10.3109/ ...
Methotrexate (MTX) remains the most commonly used disease modifying antirheumatic drug in rheumatoid arthritis (RA) because of its cost and experience in its use, despite the availability of new treatments such as leflunomide and the biological agents. However, a significant number of patients with RA either do not benefit from the drug or are unable to tolerate it. Pharmacogenetic approaches may help optimise treatment with MTX, and also other agents, in RA.. ...
Categories: Tetrahydrofolates Image Types: Photo, Illustrations, Video, Color, Black&White, PublicDomain, CopyrightRestricted 1 ...
Hydrazines inhibit metabolism of folic acid to tetrahydrofolate.. Admit all symptomatic patients in whom gyromitrin poisoning ...
M00126 Tetrahydrofolate biosynthesis, GTP => THF [PATH:eclc00790 eclc00670 eclc01240 eclc01100]. M00880 Molybdenum cofactor ...
tetrahydrofolate biosynthesis II PlantCyc GLN. Thellungiella parvula PlantCyc GLN. Theobroma cacao PlantCyc GLN. ...
What are the three units of Tetrahydrofolate (FH4)?. Definition. 1. A pteridine derivative. 2. P-aminobenzoic acid. 3. Glutamic ... Give two examples of reactions that require Tetrahydrofolate (FH4). Definition. Synthesis of glycine from serine (takes carbon ...
FH4: tetrahydrofolate. Scheme 1: Degradation of DMSP via (A) demethylation pathway and (B) cleavage pathways. FH4: ...
Family c.58.1.2: Tetrahydrofolate dehydrogenase/cyclohydrolase [53235] (1 protein). *. Protein Tetrahydrofolate dehydrogenase/ ... Timeline for Species Human (Homo sapiens) [TaxId:9606] from c.58.1.2 Tetrahydrofolate dehydrogenase/cyclohydrolase: *Species ... More info for Species Human (Homo sapiens) [TaxId:9606] from c.58.1.2 Tetrahydrofolate dehydrogenase/cyclohydrolase. ... Species Human (Homo sapiens) [TaxId:9606] from c.58.1.2 Tetrahydrofolate dehydrogenase/cyclohydrolase appears in SCOP 1.69. * ...
Tetrahydrofolate-Dependent Enzymes and Dihydrofolic Reductase in Human Tissues Enzymologia biologica et clinica (August,2017) ...
... various tetrahydrofolates (H(4)folate). -!- In contrast, the activities are located on separate proteins in most eukaryotes ... specificities with regard to one-carbon substituents and the number of glutamate residues present on the tetrahydrofolates. ...
... which generates tetrahydrofolate, an essential cofactor in nucleotide synthesis2. Depletion of tetrahydrofolate causes cell ... which generates tetrahydrofolate, an essential cofactor in nucleotide synthesis2. Depletion of tetrahydrofolate causes cell ... which generates tetrahydrofolate, an essential cofactor in nucleotide synthesis2. Depletion of tetrahydrofolate causes cell ... Mechanistically, histidine catabolism drains the cellular pool of tetrahydrofolate, which is particularly detrimental to ...
  • The most abundant circulating folate species is 5-methyl tetrahydrofolate (5-methyl-THF), which is used to synthesize methionine from homocysteine via the cobalamin-dependent enzyme methionine synthase (MTR). (nih.gov)
  • Methylene-tetrahydrofolate reductase (MTHFR) is one of the enzymes involved in folate metabolism and is thought to influence DNA methylation and nucleotide synthesis. (nih.gov)
  • 5-formyl tetrahydrofolate, aka Folinic Acid, is the natural, active coenzyme form of folate. (lifeseasons.com)
  • Both 5- methyl tetrahydrofolate (5-MTHF) and 5- formyl tetrahydrofolate (5-FTHF) are considered the metabolically active forms of folate. (lifeseasons.com)
  • Five folate forms, 5-methyltetrahydrofolate, folic acid, tetrahydrofolate, 5-formyltetrahydrofolate, 5,10-methenyltetrahydrofolate, and an oxidation product of 5-methyltetrahydrofolate called MeFox (pyrazino-s-triazine derivative of 4-α-hydroxy-5-methyltetrahydrofolate) are measured by isotope-dilution high performance liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) (Fazili, et al. (cdc.gov)
  • 4. Molecular genetic analysis of Saccharomyces cerevisiae C1-tetrahydrofolate synthase mutants reveals a noncatalytic function of the ADE3 gene product and an additional folate-dependent enzyme. (nih.gov)
  • However, the folate-dependent cleavage of serine can be described by either the same retroaldol mechanism with formaldehyde as an enzyme-bound intermediate or by a nucleophilic displacement mechanism in which N5 of tetrahydrofolate displaces the C3 hydroxyl of serine, forming a covalent intermediate. (rcsb.org)
  • The enzyme from animals and some micro-organisms also slowly reduces folate to 5,6,7,8-tetrahydrofolate. (cathdb.info)
  • DHFR catalyzes the reduction of intracellular dihydrofolate to the active coenzyme tetrahydrofolate. (nih.gov)
  • These results indicated that C-3 of glyphosate was at some point metabolized to a C-1 compound whose ultimate fate could be both oxidation to CO2 and distribution to amino acids and nucleic acid bases that receive a C-1 group from the C-1-donating coenzyme tetrahydrofolate. (nih.gov)
  • The tetrahydrofolate cycle was reconstructed by utilizing Methylobacterium extorquens formate-THF ligase, methenyl-THF cyclohydrolase, and methylene-THF dehydrogenase. (phys.org)
  • Methotrexate is an allosteric inhibititor of dihydrofolate reductase (DHFR), the enzyme that catalyzes the conversion of dihydrofolate to tetrahydrofolate. (sigmaaldrich.com)
  • Trimethoprim (TMP) prevents reduction of dihydrofolate to tetrahydrofolate. (msdmanuals.com)
  • DMGDH binds tetrahydrofolate (THF) in vivo, which serves as an acceptor of formaldehyde and in the cell the product of the reaction is 5,10-methylenetetrahydrofolate instead of formaldehyde. (nih.gov)
  • A one-carbon group transferase that transfers lipoamide-linked methylamine groups to tetrahydrofolate (TETRAHYDROFOLATES) to form methylenetetrahydrofolate and AMMONIA. (ucdenver.edu)
  • Levoleucovorin and leucovorin are analogs of tetrahydrofolate (THF) and are able to bypass DHFR reduction to act as a cellular replacement for the co-factor THF. (rcsb.org)
  • L5744] In order to function within the body, folic acid must first be reduced by the enzyme dihydrofolate reductase (DHFR) into the cofactors dihydrofolate (DHF) and tetrahydrofolate (THF). (rcsb.org)
  • ThorneVet's Basic B Complex contains the entire B-complex, including the activated forms of vitamin B2 (riboflavin 5'-phosphate), vitamin B6 (pyridoxal 5'-phosphate), folic acid (folinic acid and L-5-methyl-tetrahydrofolate), and vitamin B12 (adenosylcobalamin and methylcobalamin), as well as 80 mg choline citrate. (onlynaturalpet.com)
  • 20. 13C nuclear magnetic resonance detection of interactions of serine hydroxymethyltransferase with C1-tetrahydrofolate synthase and glycine decarboxylase complex activities in Arabidopsis. (nih.gov)
  • Serine hydroxymethyltransferase (SHMT) catalyzes the reversible interconversion of serine and glycine with tetrahydrofolate serving as the one-carbon carrier. (rcsb.org)
  • As the first step, N5 of tetrahydrofolate makes a nucleophilic attack on C3 of serine, breaking the C2-C3 bond to form N5-hydroxymethylenetetrahydrofolate and an enzyme-bound glycine anion. (rcsb.org)
  • The metabolic pathway that efficiently converts formic acid and CO 2 into pyruvate was constructed by the combined use of the tetrahydrofolate cycle and reverse glycine cleavage reaction. (phys.org)
  • Polymorphisms of methylene-tetrahydrofolate reductase and risk of lung cancer: a case-control study. (nih.gov)
  • 2. Site-directed mutagenesis of a highly conserved aspartate in the putative 10-formyl-tetrahydrofolate binding site of yeast C1-tetrahydrofolate synthase. (nih.gov)
  • It demonstrates synergy with sulfonamides, potentiating inhibition of bacterial tetrahydrofolate production. (medscape.com)
  • 8. A general method for generation and analysis of defined mutations in enzymes involved in a tetrahydrofolate-interconversion pathway. (nih.gov)
  • 18. Whole-cell detection by 13C NMR of metabolic flux through the C1-tetrahydrofolate synthase/serine hydroxymethyltransferase enzyme system and effect of antifolate exposure in Saccharomyces cerevisiae. (nih.gov)
  • 12. Regulation of expression of the ADE3 gene for yeast C1-tetrahydrofolate synthase, a trifunctional enzyme involved in one-carbon metabolism. (nih.gov)
  • tetrahydrofolate) and stopping one carbon metabolism needed for the synthesis of DNA in rapidly dividing cells. (cdc.gov)
  • Expression of Formate-Tetrahydrofolate Ligase Did Not Improve Growth but Interferes With Nitrogen and Carbon Metabolism of Synechocystissp. (mpg.de)
  • 13. Nitrous oxide exposure reduces hepatic C1-tetrahydrofolate synthase expression in rats. (nih.gov)
  • 9. Characterization of the rat cytoplasmic C1-tetrahydrofolate synthase gene and analysis of its expression in liver regeneration and fetal development. (nih.gov)
  • 5. Site-directed mutagenesis of yeast C1-tetrahydrofolate synthase: analysis of an overlapping active site in a multifunctional enzyme. (nih.gov)
  • 3. Function of yeast cytoplasmic C1-tetrahydrofolate synthase. (nih.gov)
  • 11. Mitochondrial C1-tetrahydrofolate synthase (MTHFD1L) supports the flow of mitochondrial one-carbon units into the methyl cycle in embryos. (nih.gov)
  • 6. Enzymatic characterization of human mitochondrial C1-tetrahydrofolate synthase. (nih.gov)
  • 7. Human mitochondrial C1-tetrahydrofolate synthase: gene structure, tissue distribution of the mRNA, and immunolocalization in Chinese hamster ovary calls. (nih.gov)
  • 16. Human mitochondrial C1-tetrahydrofolate synthase: submitochondrial localization of the full-length enzyme and characterization of a short isoform. (nih.gov)