Threonine (symbol Thr or T ) is an amino acid that is used in the biosynthesis of proteins . It contains an α-amino group (which is in the protonated −NH 3 form when dissolved in water), a carboxyl group (which is in the deprotonated −COO form when dissolved in water), and a side chain containing a hydroxyl group , making it a polar , uncharged amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Threonine is synthesized from aspartate in bacteria such as E. coli . It is encoded by all the codons starting AC (ACU, ACC, ACA, and ACG).
28-444: ACG may refer to: Science, technology, and health care [ edit ] A codon of threonine in genome expression Acoustocerebrography , a transcranial acoustic diagnostic method Alternating current generator, a type of electric generator American College of Gastroenterology , a professional association of gastroenterologists Angiocardiography , contrast radiography of
56-623: A US industry association of CDMA cellular network operators Association for Corporate Growth , an organization providing a global community for mergers and acquisitions and corporate growth professionals Entertainment [ edit ] ACG (subculture) , Animation, Comics, and Games subculture in Greater China American Comics Group , a comic-book publisher in the Golden Age of comic books Ashby Computers & Graphics, video game developer trading as Ultimate Play
84-738: A World Heritage site in northwestern Costa Rica Azeri-Chirag-Guneshli , an oilfield in the Caspian Sea Education and business organizations [ edit ] Academic Colleges Group , a New Zealand Educational Company Air Cargo Germany , a former cargo airline The Air Combat Group RAAF of the Royal Australian Air Force American College for Girls , now called Robert College, of Istanbul American College of Greece , an academic institution in Greece Associated Carrier Group ,
112-405: A medium effect size for negative and total symptoms of schizophrenia. There also is evidence that L ‐serine could acquire a therapeutic role in diabetes. D -Serine is being studied in rodents as a potential treatment for schizophrenia. D -Serine also has been described as a potential biomarker for early Alzheimer's disease (AD) diagnosis, due to a relatively high concentration of it in
140-414: A neuromodulator by coactivating NMDA receptors , making them able to open if they then also bind glutamate . D -serine is a potent agonist at the glycine site (NR1) of canonical diheteromeric NMDA receptors . For the receptor to open, glutamate and either glycine or D -serine must bind to it; in addition a pore blocker must not be bound (e.g. Mg or Zn ). Some research has shown that D -serine
168-471: A non-essential amino acid has come to be considered as conditional, since vertebrates such as humans cannot always synthesize optimal quantities over entire lifespans. Safety of L -serine has been demonstrated in an FDA-approved human phase I clinical trial with Amyotrophic Lateral Sclerosis, ALS , patients (ClinicalTrials.gov identifier: NCT01835782), but treatment of ALS symptoms has yet to be shown. A 2011 meta-analysis found adjunctive sarcosine to have
196-446: A patient registry was established by the noncommercial International Working Group on Neurotransmitter Related Disorders (iNTD). Besides disruption of serine biosynthesis, its transport may also become disrupted. One example is spastic tetraplegia, thin corpus callosum, and progressive microcephaly , a disease caused by mutations that affect the function of the neutral amino acid transporter A . The classification of L -serine as
224-430: A typical biosynthesis of threonine include: Threonine is metabolized in at least three ways: The degradation of threonine is impaired in the following metabolic diseases : Effects of threonine dietary supplementation have been researched in broilers. An essential amino acid, threonine is involved in the metabolism of fats, the creation of proteins, the proliferation and differentiation of embryonic stem cells , and
252-417: A variable degree to treatment with L -serine, sometimes combined with glycine. Response to treatment is variable and the long-term and functional outcome is unknown. To provide a basis for improving the understanding of the epidemiology, genotype/phenotype correlation and outcome of these diseases their impact on the quality of life of patients, as well as for evaluating diagnostic and therapeutic strategies
280-522: A very faint musty aroma. D -Serine is sweet with an additional minor sour taste at medium and high concentrations. Serine deficiency disorders are rare defects in the biosynthesis of the amino acid L -serine. At present three disorders have been reported: These enzyme defects lead to severe neurological symptoms such as congenital microcephaly and severe psychomotor retardation and in addition, in patients with 3-phosphoglycerate dehydrogenase deficiency to intractable seizures. These symptoms respond to
308-518: Is a more potent agonist at the NMDAR glycine site than glycine itself. However, D-serine has been shown to work as an antagonist/inverse co-agonist of t -NMDA receptors through the glycine binding site on the GluN3 subunit. D -serine was thought to exist only in bacteria until relatively recently; it was the second D amino acid discovered to naturally exist in humans, present as a signaling molecule in
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#1732851253423336-399: Is an α- amino acid that is used in the biosynthesis of proteins. It contains an α- amino group (which is in the protonated − NH 3 form under biological conditions), a carboxyl group (which is in the deprotonated − COO form under biological conditions), and a side chain consisting of a hydroxymethyl group, classifying it as a polar amino acid. It can be synthesized in
364-440: Is hydrolyzed to serine by phosphoserine phosphatase ( EC 3.1.3.3 ). In bacteria such as E. coli these enzymes are encoded by the genes serA (EC 1.1.1.95), serC (EC 2.6.1.52), and serB (EC 3.1.3.3). Serine hydroxymethyltransferase (SMHT) also catalyzes the biosynthesis of glycine (retro-aldol cleavage) from serine, transferring the resulting formalddehyde synthon to 5,6,7,8-tetrahydrofolate . However, that reaction
392-445: Is needed to understand how threonine controls the dynamic equilibrium of the intestinal barrier function, immunological response and gut flora. Foods high in threonine include cottage cheese , poultry , fish , meat , lentils , black turtle bean and sesame seeds. Racemic threonine can be prepared from crotonic acid by alpha-functionalization using mercury(II) acetate . Serine Serine (symbol Ser or S )
420-457: Is not synthesized in humans, and needs to be present in proteins in the diet. Adult humans require about 20 mg/kg body weight/day. In plants and microorganisms, threonine is synthesized from aspartic acid via α-aspartyl-semialdehyde and homoserine . Homoserine undergoes O -phosphorylation; this phosphate ester undergoes hydrolysis concomitant with relocation of the OH group. Enzymes involved in
448-434: Is reversible, and will convert excess glycine to serine. SHMT is a pyridoxal phosphate (PLP) dependent enzyme. Industrially, L -serine is produced from glycine and methanol catalyzed by hydroxymethyltransferase . Racemic serine can be prepared in the laboratory from methyl acrylate in several steps: Hydrogenation of serine gives the diol serinol : Serine is important in metabolism in that it participates in
476-441: The biosynthesis of purines and pyrimidines . It is the precursor to several amino acids including glycine and cysteine , as well as tryptophan in bacteria. It is also the precursor to numerous other metabolites, including sphingolipids and folate , which is the principal donor of one-carbon fragments in biosynthesis. D -Serine, synthesized in neurons by serine racemase from L -serine (its enantiomer ), serves as
504-519: The Game A Core Game, a Roblox "core" game. Other uses [ edit ] Academic Competitiveness Grant , an assistance grant for college students in the US Atlético Clube Goianiense , is a Brazilian football team All Conditions Gear (ACG), a Nike subdivision Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with
532-422: The action of a threonine kinase . In its phosphorylated form, it can be referred to as phosphothreonine. Phosphothreonine has three potential coordination sites (carboxyl, amine and phosphate group) and determination of the mode of coordination between phosphorylated ligands and metal ions occurring in an organism is important to explain the function of the phosphothreonine in biological processes. Threonine
560-462: The brain, soon after the discovery of D -aspartate . Had D amino acids been discovered in humans sooner, the glycine site on the NMDA receptor might instead be named the D -serine site. Apart from central nervous system, D -serine plays a signaling role in peripheral tissues and organs such as cartilage, kidney, and corpus cavernosum. Pure D -serine is an off-white crystalline powder with
588-457: The health and function of the intestines. Animal health and illness are strongly correlated with the need for and metabolism of threonine. Intestinal inflammation and energy metabolism disorders in animals may be alleviated by appropriate amounts of dietary threonine. Nevertheless, because these effects pertain to the control of nutrition metabolism, more research is required to confirm the results in various animal models. Furthermore, more research
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#1732851253423616-467: The heart and great vessels Angle closure glaucoma, a type of glaucoma Anterior cingulate gyrus, a part of the cingulate cortex Apexcardiogram, a graphical recording of the pulsations of the chest wall over the apex of the heart Places [ edit ] Acocks Green railway station , in the UK, from its National Railway code Área de Conservación Guanacaste , a network of protected areas and
644-407: The human body under normal physiological circumstances, making it a nonessential amino acid. It is encoded by the codons UCU, UCC, UCA, UCG, AGU and AGC. This compound is one of the proteinogenic amino acids . Only the L - stereoisomer appears naturally in proteins. It is not essential to the human diet, since it is synthesized in the body from other metabolites , including glycine . Serine
672-423: The most common small motifs formed are based on interactions with serine : ST turns , ST motifs (often at the beginning of alpha helices ) and ST staples (usually at the middle of alpha helices). The threonine residue is susceptible to numerous posttranslational modifications . The hydroxyl side-chain can undergo O -linked glycosylation . In addition, threonine residues undergo phosphorylation through
700-428: The other being isoleucine . Threonine can exist in four possible stereoisomers with the following configurations: (2 S ,3 R ), (2 R ,3 S ), (2 S ,3 S ) and (2 R ,3 R ). However, the name L -threonine is used for one single stereoisomer , (2 S ,3 R )-2-amino-3-hydroxybutanoic acid. The stereoisomer (2 S ,3 S ), which is rarely present in nature, is called L - allothreonine . As an essential amino acid, threonine
728-482: The title ACG . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=ACG&oldid=1241735986 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Threonine Threonine sidechains are often hydrogen bonded;
756-614: Was first obtained from silk protein, a particularly rich source, in 1865 by Emil Cramer. Its name is derived from the Latin for silk, sericum . Serine's structure was established in 1902. The biosynthesis of serine starts with the oxidation of 3-phosphoglycerate (an intermediate from glycolysis ) to 3-phosphohydroxypyruvate and NADH by phosphoglycerate dehydrogenase ( EC 1.1.1.95 ). Reductive amination (transamination) of this ketone by phosphoserine transaminase ( EC 2.6.1.52 ) yields 3-phosphoserine ( O -phosphoserine) which
784-413: Was the last of the 20 common proteinogenic amino acids to be discovered. It was discovered in 1935 by William Cumming Rose , collaborating with Curtis Meyer. The amino acid was named threonine because it was similar in structure to threonic acid , a four-carbon monosaccharide with molecular formula C 4 H 8 O 5 Threonine is one of two proteinogenic amino acids with two stereogenic centers,
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