Reaction Process: BioCyc:CALBI_PWY3B3-43
methionine biosynthesis related metabolites
find 7 related metabolites which is associated with chemical reaction(pathway) methionine biosynthesis
O-acetyl-L-homoserine + H2S ⟶ acetate + homocysteine
Coenzyme A
Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme notable for its role in the synthesis and oxidization of fatty acids and the oxidation of pyruvate in the citric acid cycle. It is adapted from beta-mercaptoethylamine, panthothenate, and adenosine triphosphate. It is also a parent compound for other transformation products, including but not limited to, phenylglyoxylyl-CoA, tetracosanoyl-CoA, and 6-hydroxyhex-3-enoyl-CoA. Coenzyme A is synthesized in a five-step process from pantothenate and cysteine. In the first step pantothenate (vitamin B5) is phosphorylated to 4-phosphopantothenate by the enzyme pantothenate kinase (PanK, CoaA, CoaX). In the second step, a cysteine is added to 4-phosphopantothenate by the enzyme phosphopantothenoylcysteine synthetase (PPC-DC, CoaB) to form 4-phospho-N-pantothenoylcysteine (PPC). In the third step, PPC is decarboxylated to 4-phosphopantetheine by phosphopantothenoylcysteine decarboxylase (CoaC). In the fourth step, 4-phosphopantetheine is adenylylated to form dephospho-CoA by the enzyme phosphopantetheine adenylyl transferase (CoaD). Finally, dephospho-CoA is phosphorylated using ATP to coenzyme A by the enzyme dephosphocoenzyme A kinase (CoaE). Since coenzyme A is, in chemical terms, a thiol, it can react with carboxylic acids to form thioesters, thus functioning as an acyl group carrier. CoA assists in transferring fatty acids from the cytoplasm to the mitochondria. A molecule of coenzyme A carrying an acetyl group is also referred to as acetyl-CoA. When it is not attached to an acyl group, it is usually referred to as CoASH or HSCoA. Coenzyme A is also the source of the phosphopantetheine group that is added as a prosthetic group to proteins such as acyl carrier proteins and formyltetrahydrofolate dehydrogenase. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA which is a vital component in cholesterol and ketone synthesis. Furthermore, it contributes an acetyl group to choline to produce acetylcholine in a reaction catalysed by choline acetyltransferase. Its main task is conveying the carbon atoms within the acetyl group to the citric acid cycle to be oxidized for energy production (Wikipedia). Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidization of fatty acids, and the oxidation of pyruvate in the citric acid cycle. It is adapted from beta-mercaptoethylamine, panthothenate and adenosine triphosphate. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. Furthermore, it contributes an acetyl group to choline to produce acetylcholine, in a reaction catalysed by choline acetyltransferase. Its main task is conveying the carbon atoms within the acetyl group to the citric acid cycle to be oxidized for energy production. -- Wikipedia [HMDB]. Coenzyme A is found in many foods, some of which are grape, cowpea, pili nut, and summer savory. Coenzyme A (CoASH) is a ubiquitous and essential cofactor, which is an acyl group carrier and carbonyl-activating group for the citric acid cycle and fatty acid metabolism. Coenzyme A plays a central role in the oxidation of pyruvate in the citric acid cycle and the metabolism of carboxylic acids, including short- and long-chain fatty acids[1]. Coenzyme A (CoASH) is a ubiquitous and essential cofactor, which is an acyl group carrier and carbonyl-activating group for the citric acid cycle and fatty acid metabolism. Coenzyme A plays a central role in the oxidation of pyruvate in the citric acid cycle and the metabolism of carboxylic acids, including short- and long-chain fatty acids[1]. Coenzyme A, a ubiquitous essential cofactor, is an acyl group carrier and carbonyl-activating group for the citric acid cycle and fatty acid metabolism. Coenzyme A plays a central role in the metabolism of carboxylic acids, including short- and long-chain fatty acids. Coenzyme A. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=85-61-0 (retrieved 2024-10-17) (CAS RN: 85-61-0). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0).
Homocysteine
A high level of blood serum homocysteine is a powerful risk factor for cardiovascular disease. Unfortunately, one study which attempted to decrease the risk by lowering homocysteine was not fruitful. This study was conducted on nearly 5000 Norwegian heart attack survivors who already had severe, late-stage heart disease. No study has yet been conducted in a preventive capacity on subjects who are in a relatively good state of health.; Elevated levels of homocysteine have been linked to increased fractures in elderly persons. The high level of homocysteine will auto-oxidize and react with reactive oxygen intermediates and damage endothelial cells and has a higher risk to form a thrombus. Homocysteine does not affect bone density. Instead, it appears that homocysteine affects collagen by interfering with the cross-linking between the collagen fibers and the tissues they reinforce. Whereas the HOPE-2 trial showed a reduction in stroke incidence, in those with stroke there is a high rate of hip fractures in the affected side. A trial with 2 homocysteine-lowering vitamins (folate and B12) in people with prior stroke, there was an 80\\\\\\% reduction in fractures, mainly hip, after 2 years. Interestingly, also here, bone density (and the number of falls) were identical in the vitamin and the placebo groups.; Homocysteine is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with increased incidence of cardiovascular disease and Alzheimers disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. Pyridoxal, folic acid, riboflavin, and Vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 \\\\\\%, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocysteinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD. (PMID 17136938, 15630149); Homocysteine is an amino acid with the formula HSCH2CH2CH(NH2)CO2H. It is a homologue of the amino acid cysteine, differing by an additional methylene (-CH2-) group. It is biosynthesized from methionine by the removal of its terminal C? methyl group. Homocysteine can be recycled into methionine or converted into cysteine with the aid of B-vitamins.; Studies reported in 2006 have shown that giving vitamins [folic acid, B6 and B12] to reduce homocysteine levels may not quickly offer benefit, however a significant 25\\\\\\% reduction in stroke was found in the HOPE-2 study even in patients mostly with existing serious arterial decline although the overall death rate was not significantly changed by the intervention in the trial. Clearly, reducing homocysteine does not quickly repair existing... Homocysteine (CAS: 454-29-5) is a sulfur-containing amino acid that arises during methionine metabolism. Although its concentration in plasma is only about 10 micromolar (uM), even moderate hyperhomocysteinemia is associated with an increased incidence of cardiovascular disease and Alzheimers disease. Elevations in plasma homocysteine are commonly found as a result of vitamin deficiencies, polymorphisms of enzymes of methionine metabolism, and renal disease. It has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). Pyridoxal, folic acid, riboflavin, and vitamin B(12) are all required for methionine metabolism, and deficiency of each of these vitamins result in elevated plasma homocysteine. A polymorphism of methylenetetrahydrofolate reductase (C677T), which is quite common in most populations with a homozygosity rate of 10-15 \\\\\\%, is associated with moderate hyperhomocysteinemia, especially in the context of marginal folate intake. Plasma homocysteine is inversely related to plasma creatinine in patients with renal disease. This is due to an impairment in homocysteine removal in renal disease. The role of these factors, and of modifiable lifestyle factors, in affecting methionine metabolism and in determining plasma homocysteine levels is discussed. Homocysteine is an independent cardiovascular disease (CVD) risk factor modifiable by nutrition and possibly exercise. Homocysteine was first identified as an important biological compound in 1932 and linked with human disease in 1962 when elevated urinary homocysteine levels were found in children with mental retardation. This condition, called homocystinuria, was later associated with premature occlusive CVD, even in children. These observations led to research investigating the relationship of elevated homocysteine levels and CVD in a wide variety of populations including middle age and elderly men and women with and without traditional risk factors for CVD (PMID: 17136938 , 15630149). Moreover, homocysteine is found to be associated with cystathionine beta-synthase deficiency, cystathioninuria, methylenetetrahydrofolate reductase deficiency, and sulfite oxidase deficiency, which are inborn errors of metabolism. [Spectral] L-Homocysteine (exact mass = 135.0354) and L-Valine (exact mass = 117.07898) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. Homocysteine is biosynthesized naturally via a multi-step process.[9] First, methionine receives an adenosine group from ATP, a reaction catalyzed by S-adenosyl-methionine synthetase, to give S-adenosyl methionine (SAM-e). SAM-e then transfers the methyl group to an acceptor molecule, (e.g., norepinephrine as an acceptor during epinephrine synthesis, DNA methyltransferase as an intermediate acceptor in the process of DNA methylation). The adenosine is then hydrolyzed to yield L-homocysteine. L-Homocysteine has two primary fates: conversion via tetrahydrofolate (THF) back into L-methionine or conversion to L-cysteine.[10] Biosynthesis of cysteine Mammals biosynthesize the amino acid cysteine via homocysteine. Cystathionine β-synthase catalyses the condensation of homocysteine and serine to give cystathionine. This reaction uses pyridoxine (vitamin B6) as a cofactor. Cystathionine γ-lyase then converts this double amino acid to cysteine, ammonia, and α-ketobutyrate. Bacteria and plants rely on a different pathway to produce cysteine, relying on O-acetylserine.[11] Methionine salvage Homocysteine can be recycled into methionine. This process uses N5-methyl tetrahydrofolate as the methyl donor and cobalamin (vitamin B12)-related enzymes. More detail on these enzymes can be found in the article for methionine synthase. Other reactions of biochemical significance Homocysteine can cyclize to give homocysteine thiolactone, a five-membered heterocycle. Because of this "self-looping" reaction, homocysteine-containing peptides tend to cleave themselves by reactions generating oxidative stress.[12] Homocysteine also acts as an allosteric antagonist at Dopamine D2 receptors.[13] It has been proposed that both homocysteine and its thiolactone may have played a significant role in the appearance of life on the early Earth.[14] L-Homocysteine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=454-28-4 (retrieved 2024-06-29) (CAS RN: 6027-13-0). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). DL-Homocysteine is a weak neurotoxin, and can affect the production of kynurenic acid in the brain. DL-Homocysteine is a weak neurotoxin, and can affect the production of kynurenic acid in the brain. L-Homocysteine, a homocysteine metabolite, is a homocysteine that has L configuration. L-Homocysteine induces upregulation of cathepsin V that mediates vascular endothelial inflammation in hyperhomocysteinaemia[1][2].
L-Methionine
Methionine (Met), also known as L-methionine, is an alpha-amino acid. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). Amino acids are organic compounds that contain amino (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid. Methionine is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Methionine is found in all organisms ranging from bacteria to plants to animals. It is classified as an aliphatic, non-polar amino acid. Methionine is an essential amino acid (there are 9 essential amino acids), meaning the body cannot synthesize it, and it must be obtained from the diet. It is required for normal growth and development of humans, other mammals, and avian species. In addition to being a substrate for protein synthesis, methionine is an intermediate in transmethylation reactions, serving as the major methyl group donor in vivo, including the methyl groups for DNA and RNA intermediates. Methionine is a methyl acceptor for 5-methyltetrahydrofolate-homocysteine methyltransferase (methionine synthase), the only reaction that allows for the recycling of this form of folate, and is also a methyl acceptor for the catabolism of betaine. Methionine is the metabolic precursor for cysteine. Only the sulfur atom from methionine is transferred to cysteine; the carbon skeleton of cysteine is donated by serine (PMID: 16702340 ). There is a general consensus concerning normal sulfur amino acid (SAA) requirements. WHO recommendations amount to 13 mg/kg per 24 h in healthy adults. This amount is roughly doubled in artificial nutrition regimens. In disease or after trauma, requirements may be altered for methionine, cysteine, and taurine. Although in specific cases of congenital enzyme deficiency, prematurity, or diminished liver function, hypermethioninemia or hyperhomocysteinemia may occur, SAA supplementation can be considered safe in amounts exceeding 2-3 times the minimum recommended daily intake. Apart from some very specific indications (e.g. acetaminophen poisoning) the usefulness of SAA supplementation is not yet established (PMID: 16702341 ). Methionine is known to exacerbate psychopathological symptoms in schizophrenic patients, but there is no evidence of similar effects in healthy subjects. The role of methionine as a precursor of homocysteine is the most notable cause for concern. Acute doses of methionine can lead to acute increases in plasma homocysteine, which can be used as an index of the susceptibility to cardiovascular disease. Sufficiently high doses of methionine can actually result in death. Longer-term studies in adults have indicated no adverse consequences of moderate fluctuations in dietary methionine intake, but intakes higher than 5 times the normal amount resulted in elevated homocysteine levels. These effects of methionine on homocysteine and vascular function are moderated by supplements of vitamins B-6, B-12, C, and folic acid (PMID: 16702346 ). When present in sufficiently high levels, methionine can act as an atherogen and a metabotoxin. An atherogen is a compound that when present at chronically high levels causes atherosclerosis and cardiovascular disease. A metabotoxin is an endogenously produced metabolite that causes adverse health effects at chronically high levels. Chronically high levels of methionine are associated with at least ten inborn errors of metabolism, including cystathionine beta-synthase deficiency, glycine N-methyltransferase deficiency, homocystinuria, tyrosinemia, galactosemia, homocystinuria-megaloblastic anemia due to defects in cobalamin metabolism, methionine adenosyltransferase deficiency, methylenetetrahydrofolate reductase deficiency, and S-adenosylhomocysteine (SAH) hydrolase deficiency. Chronically elevated levels of methionine in infants can lead to intellectual disability and othe... [Spectral] L-Methionine (exact mass = 149.05105) and Adenosine (exact mass = 267.09675) and S-Adenosyl-L-homocysteine (exact mass = 384.12159) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. [Spectral] L-Methionine (exact mass = 149.05105) and Tyramine (exact mass = 137.08406) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. l-Methionine. CAS Common Chemistry. CAS, a division of the American Chemical Society, n.d. https://commonchemistry.cas.org/detail?cas_rn=63-68-3 (retrieved 2024-07-01) (CAS RN: 63-68-3). Licensed under the Attribution-Noncommercial 4.0 International License (CC BY-NC 4.0). L-Methionine is the L-isomer of Methionine, an essential amino acid for human development. Methionine acts as a hepatoprotectant. L-Methionine is the L-isomer of Methionine, an essential amino acid for human development. Methionine acts as a hepatoprotectant.
Acetyl-CoA
C23H38N7O17P3S (809.1257688000001)
The main function of coenzyme A is to carry acyl groups (such as the acetyl group) or thioesters. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. (wikipedia). acetyl CoA participates in the biosynthesis of fatty acids and sterols, in the oxidation of fatty acids and in the metabolism of many amino acids. It also acts as a biological acetylating agent. The main function of coenzyme A is to carry acyl groups (such as the acetyl group) or thioesters. Acetyl-CoA is an important molecule itself. It is the precursor to HMG CoA, which is a vital component in cholesterol and ketone synthesis. (wikipedia)
Acetic acid
Acetic acid is a two-carbon, straight-chain fatty acid. It is the smallest short-chain fatty acid (SCFA) and one of the simplest carboxylic acids. is an acidic, colourless liquid and is the main component in vinegar. Acetic acid has a sour taste and pungent smell. It is an important chemical reagent and industrial chemical that is used in the production of plastic soft drink bottles, photographic film; and polyvinyl acetate for wood glue, as well as many synthetic fibres and fabrics. In households diluted acetic acid is often used as a cleaning agent. In the food industry acetic acid is used as an acidity regulator. Acetic acid is found in all organisms, from bacteria to plants to humans. The acetyl group, derived from acetic acid, is fundamental to the biochemistry of virtually all forms of life. When bound to coenzyme A (to form acetylCoA) it is central to the metabolism of carbohydrates and fats. However, the concentration of free acetic acid in cells is kept at a low level to avoid disrupting the control of the pH of the cell contents. Acetic acid is produced and excreted in large amounts by certain acetic acid bacteria, notably the Acetobacter genus and Clostridium acetobutylicum. These bacteria are found universally in foodstuffs, water, and soil. Due to their widespread presence on fruit, acetic acid is produced naturally as fruits and many other sugar-rich foods spoil. Several species of anaerobic bacteria, including members of the genus Clostridium and Acetobacterium can convert sugars to acetic acid directly. However, Clostridium bacteria are less acid-tolerant than Acetobacter. Even the most acid-tolerant Clostridium strains can produce acetic acid in concentrations of only a few per cent, compared to Acetobacter strains that can produce acetic acid in concentrations up to 20\\%. Acetic acid is also a component of the vaginal lubrication of humans and other primates, where it appears to serve as a mild antibacterial agent. Acetic acid can be found in other biofluids such as urine at low concentrations. Urinary acetic acid is produced by bacteria such as Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Enterobacter, Acinetobacter, Proteus mirabilis, Citrobacter frundii, Enterococcus faecalis, Streptococcus group B, Staphylococcus saprophyticus (PMID: 22292465). Acetic acid concentrations greater than 30 uM/mM creatinine in the urine can indicate a urinary tract infection, which typically suggests the presence of E. coli or Klebshiella pneumonia in the urinary tract. (PMID: 24909875) Acetic acid is also produced by other bacteria such as Akkermansia, Bacteroidetes, Bifidobacterium, Prevotella and Ruminococcus (PMID: 20444704; PMID: 22292465). G - Genito urinary system and sex hormones > G01 - Gynecological antiinfectives and antiseptics > G01A - Antiinfectives and antiseptics, excl. combinations with corticosteroids > G01AD - Organic acids S - Sensory organs > S02 - Otologicals > S02A - Antiinfectives > S02AA - Antiinfectives D019995 - Laboratory Chemicals > D007202 - Indicators and Reagents D000890 - Anti-Infective Agents > D000900 - Anti-Bacterial Agents It is used for smoking meats and fish C254 - Anti-Infective Agent KEIO_ID A029
O-acetylhomoserine
Acetylhomoserine is found in pulses. Acetylhomoserine is found in Pisum sativum (peas) Acquisition and generation of the data is financially supported in part by CREST/JST. Found in green tissues of pea (Pisum sativum)
Hydrogen sulfide
Hydrogen sulfide, also known as h2s or acide sulfhydrique, is a member of the class of compounds known as other non-metal sulfides. Other non-metal sulfides are inorganic compounds containing a sulfur atom of an oxidation state of -2, in which the heaviest atom bonded to the oxygen belongs to the class of other non-metals. Hydrogen sulfide can be found in a number of food items such as small-leaf linden, agar, devilfish, and nutmeg, which makes hydrogen sulfide a potential biomarker for the consumption of these food products. Hydrogen sulfide can be found primarily in blood and feces, as well as throughout most human tissues. Hydrogen sulfide exists in all living species, ranging from bacteria to humans. In humans, hydrogen sulfide is involved in a couple of metabolic pathways, which include cysteine metabolism and cystinosis, ocular nonnephropathic. Hydrogen sulfide is also involved in beta-mercaptolactate-cysteine disulfiduria, which is a metabolic disorder. Moreover, hydrogen sulfide is found to be associated with hydrogen sulfide poisoning. Hydrogen sulfide is a non-carcinogenic (not listed by IARC) potentially toxic compound. Hydrogen sulfide often results from the microbial breakdown of organic matter in the absence of oxygen gas, such as in swamps and sewers; this process is commonly known as anaerobic digestion. H 2S also occurs in volcanic gases, natural gas, and in some sources of well water. The human body produces small amounts of H 2S and uses it as a signaling molecule . Treatment involves immediate inhalation of amyl nitrite, injections of sodium nitrite, inhalation of pure oxygen, administration of bronchodilators to overcome eventual bronchospasm, and in some cases hyperbaric oxygen therapy (HBO). HBO therapy has anecdotal support and remains controversial (L1139) (T3DB). Hydrogen sulfide is a highly toxic and flammable gas. Because it is heavier than air it tends to accumulate at the bottom of poorly ventilated spaces. Although very pungent at first, it quickly deadens the sense of smell, so potential victims may be unaware of its presence until it is too late. H2S arises from virtually anywhere where elemental sulfur comes into contact with organic material, especially at high temperatures. Hydrogen sulfide is a covalent hydride chemically related to water (H2O) since oxygen and sulfur occur in the same periodic table group. It often results when bacteria break down organic matter in the absence of oxygen, such as in swamps, and sewers (alongside the process of anaerobic digestion). It also occurs in volcanic gases, natural gas and some well waters. It is also important to note that Hydrogen sulfide is a central participant in the sulfur cycle, the biogeochemical cycle of sulfur on Earth. As mentioned above, sulfur-reducing and sulfate-reducing bacteria derive energy from oxidizing hydrogen or organic molecules in the absence of oxygen by reducing sulfur or sulfate to hydrogen sulfide. Other bacteria liberate hydrogen sulfide from sulfur-containing amino acids. Several groups of bacteria can use hydrogen sulfide as fuel, oxidizing it to elemental sulfur or to sulfate by using oxygen or nitrate as oxidant. The purple sulfur bacteria and the green sulfur bacteria use hydrogen sulfide as electron donor in photosynthesis, thereby producing elemental sulfur. (In fact, this mode of photosynthesis is older than the mode of cyanobacteria, algae and plants which uses water as electron donor and liberates oxygen). Hydrogen sulfide can be found in Alcaligenes, Chromobacteriumn, Klebsiella, Proteus and Pseudomonas (PMID: 13061742). D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D004785 - Environmental Pollutants > D000393 - Air Pollutants