L-Glutamic acid (BioDeep_00000000342)

描述信息

Glutamic acid (Glu), also known as L-glutamic acid or as glutamate, the name of its anion, 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. L-glutamic acid is one of 20 proteinogenic amino acids, i.e., the amino acids used in the biosynthesis of proteins. Glutamic acid is found in all organisms ranging from bacteria to plants to animals. It is classified as an acidic, charged (at physiological pH), aliphatic amino acid. In humans it is a non-essential amino acid and can be synthesized via alanine or aspartic acid via alpha-ketoglutarate and the action of various transaminases. Glutamate also plays an important role in the bodys disposal of excess or waste nitrogen. Glutamate undergoes deamination, an oxidative reaction catalysed by glutamate dehydrogenase leading to alpha-ketoglutarate. In many respects glutamate is a key molecule in cellular metabolism. Glutamate is the most abundant fast excitatory neurotransmitter in the mammalian nervous system. At chemical synapses, glutamate is stored in vesicles. Nerve impulses trigger release of glutamate from the pre-synaptic cell. In the opposing post-synaptic cell, glutamate receptors, such as the NMDA receptor, bind glutamate and are activated. Because of its role in synaptic plasticity, it is believed that glutamic acid is involved in cognitive functions like learning and memory in the brain. Glutamate transporters are found in neuronal and glial membranes. They rapidly remove glutamate from the extracellular space. In brain injury or disease, they can work in reverse and excess glutamate can accumulate outside cells. This process causes calcium ions to enter cells via NMDA receptor channels, leading to neuronal damage and eventual cell death, and is called excitotoxicity. The mechanisms of cell death include: Damage to mitochondria from excessively high intracellular Ca2+. Glu/Ca2+-mediated promotion of transcription factors for pro-apoptotic genes, or downregulation of transcription factors for anti-apoptotic genes. Excitotoxicity due to glutamate occurs as part of the ischemic cascade and is associated with stroke and diseases like amyotrophic lateral sclerosis, lathyrism, and Alzheimers disease. Glutamic acid has been implicated in epileptic seizures. Microinjection of glutamic acid into neurons produces spontaneous depolarization around one second apart, and this firing pattern is similar to what is known as paroxysmal depolarizing shift in epileptic attacks. This change in the resting membrane potential at seizure foci could cause spontaneous opening of voltage activated calcium channels, leading to glutamic acid release and further depolarization (http://en.wikipedia.org/wiki/Glutamic_acid). Glutamate was discovered in 1866 when it was extracted from wheat gluten (from where it got its name. Glutamate has an important role as a food additive and food flavoring agent. In 1908, Japanese researcher Kikunae Ikeda identified brown crystals left behind after the evaporation of a large amount of kombu broth (a Japanese soup) as glutamic acid. These crystals, when tasted, reproduced a salty, savory flavor 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.
L-glutamic acid is an optically active form of glutamic acid having L-configuration. It has a role as a nutraceutical, a micronutrient, an Escherichia coli metabolite, a mouse metabolite, a ferroptosis inducer and a neurotransmitter. It is a glutamine family amino acid, a proteinogenic amino acid, a glutamic acid and a L-alpha-amino acid. It is a conjugate acid of a L-glutamate(1-). It is an enantiomer of a D-glutamic acid.
A peptide that is a homopolymer of glutamic acid.
L-Glutamic acid is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Glutamic acid (Glu), also referred to as glutamate (the anion), is one of the 20 proteinogenic amino acids. It is not among the essential amino acids. Glutamate is a key molecule in cellular metabolism. In humans, dietary proteins are broken down by digestion into amino acids, which serves as metabolic fuel or other functional roles in the body. Glutamate is the most abundant fast excitatory neurotransmitter in the mammalian nervous system. At chemical synapses, glutamate is stored in vesicles. Nerve impulses trigger release of glutamate from the pre-synaptic cell. In the opposing post-synaptic cell, glutamate receptors, such as the NMDA receptor, bind glutamate and are activated. Because of its role in synaptic plasticity, it is believed that glutamic acid is involved in cognitive functions like learning and memory in the brain. Glutamate transporters are found in neuronal and glial membranes. They rapidly remove glutamate from the extracellular space. In brain injury or disease, they can work in reverse and excess glutamate can accumulate outside cells. This process causes calcium ions to enter cells via NMDA receptor channels, leading to neuronal damage and eventual cell death, and is called excitotoxicity. The mechanisms of cell death include: * Damage to mitochondria from excessively high intracellular Ca2+. * Glu/Ca2+-mediated promotion of transcription factors for pro-apoptotic genes, or downregulation of transcription factors for anti-apoptotic genes. Excitotoxicity due to glutamate occurs as part of the ischemic cascade and is associated with stroke and diseases like amyotrophic lateral sclerosis, lathyrism, and Alzheimers disease. glutamic acid has been implicated in epileptic seizures. Microinjection of glutamic acid into neurons produces spontaneous depolarization around one second apart, and this firing pattern is similar to what is known as paroxysmal depolarizing shift in epileptic attacks. This change in the resting membrane potential at seizure foci could cause spontaneous opening of voltage activated calcium channels, leading to glutamic acid release and further depolarization.
A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.
See also: Monosodium Glutamate (active moiety of); Glatiramer Acetate (monomer of); Glatiramer (monomer of) ... View More ...
obtained from acid hydrolysis of proteins. Since 1965 the industrial source of glutamic acid for MSG production has been bacterial fermentation of carbohydrate sources such as molasses and corn starch hydrolysate in the presence of a nitrogen source such as ammonium salts or urea. Annual production approx. 350000t worldwide in 1988. Seasoning additive in food manuf. (as Na, K and NH4 salts). Dietary supplement, nutrient

Glutamic acid (symbol Glu or E;[4] 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 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
5H
9NO
4. Glutamic acid exists in two optically isomeric forms; the dextrorotatory l-form is usually obtained by hydrolysis of gluten or from the waste waters of beet-sugar manufacture or by fermentation.[5][full citation needed] 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 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.[6] This anion creates the savory umami flavor of foods and 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 in alphabetical sequence to D for aspartate, being larger by one methylene –CH2– group.[7]
DL-Glutamic acid is the conjugate acid of Glutamic acid, which acts as a fundamental metabolite. Comparing with the second phase of polymorphs α and β L-Glutamic acid, DL-Glutamic acid presents better stability[1].
DL-Glutamic acid is the conjugate acid of Glutamic acid, which acts as a fundamental metabolite. Comparing with the second phase of polymorphs α and β L-Glutamic acid, DL-Glutamic acid presents better stability[1].
L-Glutamic acid acts as an excitatory transmitter and an agonist at all subtypes of glutamate receptors (metabotropic, kainate, NMDA, and AMPA). L-Glutamic acid shows a direct activating effect on the release of DA from dopaminergic terminals.
L-Glutamic acid is an excitatory amino acid neurotransmitter that acts as an agonist for all subtypes of glutamate receptors (metabolic rhodophylline, NMDA, and AMPA). L-Glutamic acid has an agonist effect on the release of DA from dopaminergic nerve endings. L-Glutamic acid can be used in the study of neurological diseases[1][2][3][4][5].
L-Glutamic acid acts as an excitatory transmitter and an agonist at all subtypes of glutamate receptors (metabotropic, kainate, NMDA, and AMPA). L-Glutamic acid shows a direct activating effect on the release of DA from dopaminergic terminals.

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