10157
41-456: AASS or Aass may refer to: Alpha-aminoadipic semialdehyde synthase American Anti-Slavery Society abolitionist society in existence from 1833 to 1870 Aass Brewery , Norway's oldest active brewery Th. Valentin Aass (1887–1961), Norwegian sailor and civil servant See also [ edit ] Aas (disambiguation) Topics referred to by
82-543: A neighboring synapse creates extrasynaptic signaling/ volume transmission . In addition, glutamate plays important roles in the regulation of growth cones and synaptogenesis during brain development as originally described by Mark Mattson . Extracellular glutamate in Drosophila brains has been found to regulate postsynaptic glutamate receptor clustering, via a process involving receptor desensitization. A gene expressed in glial cells actively transports glutamate into
123-543: A structure of alpha-aminoadipic semialdehyde synthase has not been determined. The enzyme does not have linker region present in plants between its C and N-termini, so theories suggest the actual structure contains an LKR-activity region bound to an SHD-activity region, like that in Magnaporthe grisea . Alpha-aminoadipic semialdehyde synthase is encoded for by the AASS gene, and mutations in this gene lead to hyperlysinemia. This
164-401: Is chiral ; two mirror-image enantiomers exist: d (−), and l (+). The l form is more widely occurring in nature, but the d form occurs in some special contexts, such as the bacterial capsule and cell walls of the bacteria (which produce it from the l form with the enzyme glutamate racemase ) and the liver of mammals . Although they occur naturally in many foods,
205-432: Is encoded by the codons GAA or GAG. The acid can lose one proton from its second carboxyl group to form the conjugate base , the singly-negative anion glutamate OOC−CH( NH 3 )−( CH 2 ) 2 −COO . This form of the compound is prevalent in neutral solutions. The glutamate neurotransmitter plays the principal role in neural activation . This anion creates the savory umami flavor of foods and
246-550: Is bifunctional, much like the LKR/SHD found in plants, and thus, is thought to be similar in structure. The bifunctionality of this enzyme comes from the fact that it contains two distinct active sites, one at its C-terminal, and one at its N-terminal. The C-terminal portion of alpha-aminoadipic semialdehyde synthase contains the SHD activity and the N-terminal portion contains LKR. To date,
287-509: Is catalyzed by glutamate decarboxylase (GAD). GABA-ergic neurons are identified (for research purposes) by revealing its activity (with the autoradiography and immunohistochemistry methods) which is most abundant in the cerebellum and pancreas . Stiff person syndrome is a neurologic disorder caused by anti-GAD antibodies, leading to a decrease in GABA synthesis and, therefore, impaired motor function such as muscle stiffness and spasm. Since
328-452: Is characterized by impaired breakdown of lysine which results in elevated levels of lysine in the blood and urine. These increased levels of lysine do not appear to have any negative effects on the body. Other names for this condition include: Hyperlysinemia is characterized by elevated plasma lysine levels that exceed 600 μmol/L and can reach up to 2000 μmol/L. These increased levels of lysine do not appear to have any negative effects on
369-401: Is dienoyl-CoA reductase deficiency, though this is a relatively recent discovery and there are not many publications supporting this. Glutamic acid Glutamic acid (symbol Glu or E ; the anionic form is known as glutamate ) is an α- amino acid that is used by almost all living beings in the biosynthesis of proteins . It is a non-essential nutrient for humans, meaning that
410-448: Is different from Wikidata All article disambiguation pages All disambiguation pages Alpha-aminoadipic semialdehyde synthase 30956 ENSG00000008311 ENSMUSG00000029695 Q9UDR5 Q99K67 NM_005763 NM_013930 NP_005754 NP_038958 Alpha-aminoadipic semialdehyde synthase is an enzyme encoded by the AASS gene in humans and is involved in their major lysine degradation pathway. It
451-418: Is dissolved in water, the amino group (− NH 2 ) may gain a proton ( H ), and/or the carboxyl groups may lose protons, depending on the acidity of the medium. In sufficiently acidic environments, both carboxyl groups are protonated and the molecule becomes a cation with a single positive charge, HOOC−CH( NH 3 )−( CH 2 ) 2 −COOH. At pH values between about 2.5 and 4.1,
SECTION 10
#1732852087936492-458: Is found in glutamate flavorings such as MSG . In Europe, it is classified as food additive E620 . In highly alkaline solutions the doubly negative anion OOC−CH( NH 2 )−( CH 2 ) 2 −COO prevails. The radical corresponding to glutamate is called glutamyl . The one-letter symbol E for glutamate was assigned as the letter following D for aspartate , as glutamate is larger by one methylene –CH 2 – group. When glutamic acid
533-415: Is involved in cognitive functions such as learning and memory in the brain. The form of plasticity known as long-term potentiation takes place at glutamatergic synapses in the hippocampus , neocortex , and other parts of the brain. Glutamate works not only as a point-to-point transmitter, but also through spill-over synaptic crosstalk between synapses in which summation of glutamate released from
574-399: Is often a useful one as well, which can contribute as fuel or as a substrate for further metabolism processes. Examples are as follows: Both pyruvate and oxaloacetate are key components of cellular metabolism, contributing as substrates or intermediates in fundamental processes such as glycolysis , gluconeogenesis , and the citric acid cycle . Glutamate also plays an important role in
615-498: Is often used as an alignment medium to control the scale of the dipolar interactions observed. The drug phencyclidine (more commonly known as PCP or 'Angel Dust') antagonizes glutamic acid non-competitively at the NMDA receptor . For the same reasons, dextromethorphan and ketamine also have strong dissociative and hallucinogenic effects. Acute infusion of the drug eglumetad (also known as eglumegad or LY354740), an agonist of
656-419: Is responsible for umami , one of the five basic tastes of the human sense of taste . Glutamic acid often is used as a food additive and flavor enhancer in the form of its sodium salt , known as monosodium glutamate (MSG). All meats, poultry, fish, eggs, dairy products, and kombu are excellent sources of glutamic acid. Some protein-rich plant foods also serve as sources. 30% to 35% of gluten (much of
697-570: Is similar to the separate enzymes coded for by the LYS1 and LYS9 genes in yeast, and related to, although not similar in structure, the bifunctional enzyme found in plants. In humans, mutations in the AASS gene, and the corresponding alpha-aminoadipic semialdehyde synthase enzyme are associated with familial hyperlysinemia . This rare disease is inherited in an autosomal recessive pattern and patients often have no clinical symptoms. The alpha-aminoadipic semialdehyde synthase protein catalyzes
738-475: Is usually obtained by hydrolysis of gluten or from the waste waters of beet -sugar manufacture or by fermentation. Its molecular structure could be idealized as HOOC−CH( NH 2 )−( CH 2 ) 2 −COOH, with two carboxyl groups −COOH and one amino group − NH 2 . However, in the solid state and mildly acidic water solutions, the molecule assumes an electrically neutral zwitterion structure OOC−CH( NH 3 )−( CH 2 ) 2 −COOH. It
779-514: The extracellular space , while, in the nucleus accumbens -stimulating group II metabotropic glutamate receptors , this gene was found to reduce extracellular glutamate levels. This raises the possibility that this extracellular glutamate plays an "endocrine-like" role as part of a larger homeostatic system. Glutamate also serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABA-ergic neurons. This reaction
820-528: The metabotropic glutamate receptors 2 and 3 ) resulted in a marked diminution of yohimbine -induced stress response in bonnet macaques ( Macaca radiata ); chronic oral administration of eglumetad in those animals led to markedly reduced baseline cortisol levels (approximately 50 percent) in comparison to untreated control subjects. Eglumetad has also been demonstrated to act on the metabotropic glutamate receptor 3 (GRM3) of human adrenocortical cells , downregulating aldosterone synthase , CYP11B1 , and
861-521: The Citric Acid/Kreb cycle enzyme complex 2-oxoglutarate dehydrogenase. Two types of familial hyperlysinemia have been described so far: type I is associated with a combined deficiency of the two enzyme activities, LOR and SDH, whereas in familial hyperlysinemia type II only the saccharopine dehydrogenase activity is impaired. Type II hyperlysinemia is also referred to as saccharopinuria. An additional condition shown to be related to hyperlysinemia
SECTION 20
#1732852087936902-472: The L-lysine degradation via saccharopine pathway are the intermediately-used reaction/product glutamate and the eventual carbon sink acetyl-CoA . Glutamate is an important compound within the body which acts as a neurotransmitter tied to learning and Huntington's disease. Acetyl-CoA is arguably of an even higher level of importance, acting as one of the integral components of the Citric Acid/Kreb cycle, with
943-537: The acid exists almost entirely as the glutamate anion OOC−CH( NH 3 )−( CH 2 ) 2 −COO , with a single negative charge overall. The change in protonation state occurs at pH 4.07. This form with both carboxylates lacking protons is dominant in the physiological pH range (7.35–7.45). At even higher pH, the amino group loses the extra proton, and the prevalent species is the doubly-negative anion OOC−CH( NH 2 )−( CH 2 ) 2 −COO . The change in protonation state occurs at pH 9.47. Glutamic acid
984-439: The body in the form of urea. Glutamate is also a neurotransmitter (see below), which makes it one of the most abundant molecules in the brain. Malignant brain tumors known as glioma or glioblastoma exploit this phenomenon by using glutamate as an energy source, especially when these tumors become more dependent on glutamate due to mutations in the gene IDH1 . Glutamate is the most abundant excitatory neurotransmitter in
1025-448: The body's disposal of excess or waste nitrogen . Glutamate undergoes deamination , an oxidative reaction catalysed by glutamate dehydrogenase , as follows: Ammonia (as ammonium ) is then excreted predominantly as urea , synthesised in the liver . Transamination can thus be linked to deamination, effectively allowing nitrogen from the amine groups of amino acids to be removed, via glutamate as an intermediate, and finally excreted from
1066-453: The body. The main reason for this is that several alternative biochemical reactions can take place. First, lysine can be used in place of ornithine in the urea cycle resulting in the production of homoarginine . Additionally, even though most mammals use the saccharopine pathway for most lysine degradation (Path 1), the brain has an alternative pathway (Path 2) which goes through an L-pipecolic acid intermediate - both of these can be seen in
1107-407: The body. A key process in amino acid degradation is transamination , in which the amino group of an amino acid is transferred to an α- ketoacid , typically catalysed by a transaminase . The reaction can be generalised as such: A very common α-keto acid is α-ketoglutarate , an intermediate in the citric acid cycle . Transamination of α-ketoglutarate gives glutamate. The resulting α-ketoacid product
1148-407: The carboxylic acid closer to the amine generally loses a proton, and the acid becomes the neutral zwitterion OOC−CH( NH 3 )−( CH 2 ) 2 −COOH. This is also the form of the compound in the crystalline solid state. The change in protonation state is gradual; the two forms are in equal concentrations at pH 2.10. At even higher pH, the other carboxylic acid group loses its proton and
1189-509: The evaporation of a large amount of kombu broth as glutamic acid. These crystals, when tasted, reproduced the ineffable but undeniable flavor he detected in many foods, most especially in seaweed. Professor Ikeda termed this flavor umami . He then patented a method of mass-producing a crystalline salt of glutamic acid, monosodium glutamate . Glutamic acid is produced on the largest scale of any amino acid, with an estimated annual production of about 1.5 million tons in 2006. Chemical synthesis
1230-789: The figure to the right). Then, the C-terminal portion of this enzyme, which contains saccharopine dehydrogenase (SHD) activity (EC:1.5.1.9), catalyzes the oxidation of saccharopine to produce alpha-aminoadipic semialdehyde and glutamate (Reaction 2 on the figure to the right). Note: These reactions are the reverse of the corresponding steps in the lysine biosynthesis pathways present in yeast and fungi . These reactions can be visualized as well in reaction equation form: N(6)-(L-1,3-dicarboxypropyl)-L-lysine + NADP + H 2 O = L-lysine + 2-oxoglutarate + NADPH followed by N(6)-(L-1,3-dicarboxypropyl)-L-lysine + NAD + H 2 O = L-glutamate + (S)-2-amino-6-oxohexanoate + NADH. The native human enzyme
1271-403: The figure. It is important to note that Path 1 takes place in the mitochondria while Path 2 takes places in the peroxisome. Looking at other key enzymes within the L-lysine degradation pathway, ALDH7A1 is deficient in children with pyridoxine-dependent seizures. GCDH is deficient in glutaric aciduria type 1. The intermediate 2-oxoadipate is metabolized by 2-oxoadipate dehydrogenase, resembling
AASS - Misplaced Pages Continue
1312-463: The first two steps in the mammalian L- lysine degradation via saccharopine pathway within the mitochondria , which is thought to be the main metabolic route for lysine degradation in upper eukaryotes . The specific subpathway that this enzyme focuses on is the synthesis of glutaryl-CoA from L-lysine. Glutaryl-CoA can act as an intermediate in a more expanded conversion/degradation pathway from L-lysine to acetyl-CoA. Two noticeable components of
1353-557: The flavor contributions made by glutamic acid and other amino acids were only scientifically identified early in the 20th century. The substance was discovered and identified in the year 1866 by the German chemist Karl Heinrich Ritthausen , who treated wheat gluten (for which it was named) with sulfuric acid . In 1908, Japanese researcher Kikunae Ikeda of the Tokyo Imperial University identified brown crystals left behind after
1394-461: The human body can synthesize enough for its use. It is also the most abundant excitatory neurotransmitter in the vertebrate nervous system . It serves as the precursor for the synthesis of the inhibitory gamma-aminobutyric acid (GABA) in GABAergic neurons. Its molecular formula is C 5 H 9 NO 4 . Glutamic acid exists in two optically isomeric forms; the dextrorotatory L -form
1435-431: The pancreas has abundant GAD, a direct immunological destruction occurs in the pancreas and the patients will have diabetes mellitus . Glutamic acid, being a constituent of protein, is present in foods that contain protein, but it can only be tasted when it is present in an unbound form. Significant amounts of free glutamic acid are present in a wide variety of foods, including cheeses and soy sauce , and glutamic acid
1476-491: The primary function of delivering an acetyl group to be oxidized for energy production. Thus, the function of alpha-aminoadipic semialdehyde synthase is tied to the levels of two integral compounds within the body. First, the N-terminal portion of this enzyme which contains lysine - ketoglutarate reductase (LOR/LKR) activity ( EC :1.5.1.8) condenses lysine and 2-oxoglutarate to a molecule called saccharopine (Reaction 1 on
1517-458: The production of adrenal steroids (i.e. aldosterone and cortisol ). Glutamate does not easily pass the blood brain barrier , but, instead, is transported by a high-affinity transport system. It can also be converted into glutamine . Glutamate toxicity can be reduced by antioxidants , and the psychoactive principle of cannabis , tetrahydrocannabinol (THC), and the non psychoactive principle cannabidiol (CBD), and other cannabinoids ,
1558-427: The protein in wheat) is glutamic acid. Ninety-five percent of the dietary glutamate is metabolized by intestinal cells in a first pass. Auxigro is a plant growth preparation that contains 30% glutamic acid. In recent years, there has been much research into the use of residual dipolar coupling (RDC) in nuclear magnetic resonance spectroscopy (NMR). A glutamic acid derivative, poly-γ-benzyl-L-glutamate (PBLG),
1599-458: The same term [REDACTED] This disambiguation page lists articles associated with the title AASS . 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=AASS&oldid=983812252 " Categories : Disambiguation pages Disambiguation pages with surname-holder lists Hidden categories: Short description
1640-504: The vertebrate nervous system . At chemical synapses , glutamate is stored in vesicles . Nerve impulses trigger the release of glutamate from the presynaptic cell. Glutamate acts on ionotropic and metabotropic ( G-protein coupled ) receptors. In the opposing postsynaptic cell, glutamate receptors , such as the NMDA receptor or the AMPA receptor , bind glutamate and are activated. Because of its role in synaptic plasticity , glutamate
1681-549: Was supplanted by the aerobic fermentation of sugars and ammonia in the 1950s, with the organism Corynebacterium glutamicum (also known as Brevibacterium flavum ) being the most widely used for production. Isolation and purification can be achieved by concentration and crystallization ; it is also widely available as its hydrochloride salt. Glutamate is a key compound in cellular metabolism . In humans, dietary proteins are broken down by digestion into amino acids , which serve as metabolic fuel for other functional roles in