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International Working Group On Neurotransmitter Related Disorders
The International Working Group on Neurotransmitter Related Disorders is an international collaboration of researchers studying neurotransmitter disorders. It has created a patient registry for longitudinal studies. The group studies deficiencies in aromatic amino acid decarboxylase, tyrosine hydroxylase, dopamine beta-hydroxylase, monoamine oxidase A, dopamine transporter, vesicular monoamine transporter 2 GTP cyclohydrolase (Segawa disease), 6-Pyruvoyltetrahydropterin synthase deficiency, 6-pyruvoyl-tetrahydropterin synthase, dihydropteridine reductase, sepiapterin reductase, folate receptor alpha, dihydrofolate reductase, 3-phosphoglycerate dehydrogenase, 3-phosphoserine phosphatase, phosphoserine aminotransferase, the glycine cleavage system (the deficiency is called glycine encephalopathy or non-ketotic hyperglycinaemia), GABA-transaminase, and Succinic semialdehyde dehydrogenase deficiency, succinate-semialdehyde dehydroxylase. References External links Rare diseases P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotransmitters are released from synaptic vesicles into the synaptic cleft where they are able to interact with neurotransmitter receptors on the target cell. The neurotransmitter's effect on the target cell is determined by the receptor it binds. Many neurotransmitters are synthesized from simple and plentiful precursors such as amino acids, which are readily available and often require a small number of biosynthetic steps for conversion. Neurotransmitters are essential to the function of complex neural systems. The exact number of unique neurotransmitters in humans is unknown, but more than 100 have been identified. Common neurotransmitters include glutamate, GABA, acetylcholine, glycine and norepinephrine. Mechanism and cycle Synthes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Folate Receptor Alpha
Folate receptor 1 (Folate receptor alpha, FOLR1) is a protein that in humans is encoded by the ''FOLR1'' gene. The protein encoded by this gene is a member of the folate receptor (FOLR) family. Members of this family have a high affinity for folic acid and for several reduced folic acid derivatives, and mediate delivery of 5-methyltetrahydrofolate to the interior of cells. Functions This receptor is responsible for binding to folic acid and its derivatives, which becomes crucial during fetal development. By adding folate supplementation during pregnancy, neural tube defects in the fetus are prevented. Folate derivatives are necessary for important metabolic processes such as DNA, protein and lipid methylation. More importantly, folate plays a major role in DNA replication and cell division, which are common characteristics of rapid growth. Even though it is unclear how folate affects neural tube formation, scientists are certain that without appropriate folate levels, neural tub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Succinic Semialdehyde Dehydrogenase Deficiency
Succinic semialdehyde dehydrogenase deficiency (SSADHD) is a rare autosomal recessive disorder of the degradation pathway of the inhibitory neurotransmitter γ-aminobutyric acid, or GABA. The disorder has been identified in approximately 350 families, with a significant proportion being consanguineous families. The first case was identified in 1981 and published in a Dutch clinical chemistry journal that highlighted a number of neurological conditions such as delayed intellectual, motor, speech, and language as the most common manifestations. Later cases reported in the early 1990s began to show that hypotonia, hyporeflexia, seizures, and a nonprogressive ataxia were frequent clinical features as well. SSADH deficiency is caused by an enzyme deficiency in GABA degradation. Under normal conditions, SSADH works with the enzyme GABA transaminase to convert GABA to succinic acid. Succinic acid can then be utilized for energy production via the Krebs cycle. However, because of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABA-transaminase
In enzymology, 4-aminobutyrate transaminase (), also called GABA transaminase or 4-aminobutyrate aminotransferase, or GABA-T, is an enzyme that catalyzes the chemical reaction: :4-aminobutanoate + 2-oxoglutarate \rightleftharpoons succinate semialdehyde + L-glutamate Thus, the two substrates of this enzyme are 4-aminobutanoate ( GABA) and 2-oxoglutarate. The two products are succinate semialdehyde and L-glutamate. This enzyme belongs to the family of transferases, specifically the transaminases, which transfer nitrogenous groups. The systematic name of this enzyme class is 4-aminobutanoate:2-oxoglutarate aminotransferase. This enzyme participates in 5 metabolic pathways: alanine and aspartate metabolism, glutamate metabolism, beta-alanine metabolism, propanoate metabolism, and butanoate metabolism. It employs one cofactor, pyridoxal phosphate. This enzyme is found in prokaryotes, plants, fungi, and animals (including humans). Pigs have often been used when studying h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-ketotic Hyperglycinaemia
Glycine encephalopathy is a rare autosomal recessive disorder of glycine metabolism. After phenylketonuria, glycine encephalopathy is the second most common disorder of amino acid metabolism. The disease is caused by defects in the glycine cleavage system, an enzyme responsible for glycine catabolism. There are several forms of the disease, with varying severity of symptoms and time of onset. The symptoms are exclusively neurological in nature, and clinically this disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues, especially the cerebrospinal fluid. Glycine encephalopathy is sometimes referred to as "nonketotic hyperglycinemia" (NKH), as a reference to the biochemical findings seen in patients with the disorder, and to distinguish it from the disorders that cause "ketotic hyperglycinemia" (seen in propionic acidemia and several other inherited metabolic disorders). To avoid confusion, the term "glycine encephalopathy" is of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine Encephalopathy
Glycine encephalopathy is a rare autosomal recessive disorder of glycine metabolism. After phenylketonuria, glycine encephalopathy is the second most common disorder of amino acid metabolism. The disease is caused by defects in the glycine cleavage system, an enzyme responsible for glycine catabolism. There are several forms of the disease, with varying severity of symptoms and time of onset. The symptoms are exclusively neurological in nature, and clinically this disorder is characterized by abnormally high levels of the amino acid glycine in bodily fluids and tissues, especially the cerebrospinal fluid. Glycine encephalopathy is sometimes referred to as "nonketotic hyperglycinemia" (NKH), as a reference to the biochemical findings seen in patients with the disorder, and to distinguish it from the disorders that cause "ketotic hyperglycinemia" (seen in propionic acidemia and several other inherited metabolic disorders). To avoid confusion, the term "glycine encephalopathy" is oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycine Cleavage System
The glycine cleavage system (GCS) is also known as the glycine decarboxylase complex or GDC. The system is a series of enzymes that are triggered in response to high concentrations of the amino acid glycine. The same set of enzymes is sometimes referred to as glycine synthase when it runs in the reverse direction to form glycine. The glycine cleavage system is composed of four proteins: the T-protein, P-protein, L-protein, and H-protein. They do not form a stable complex, so it is more appropriate to call it a "system" instead of a "complex". The H-protein is responsible for interacting with the three other proteins and acts as a shuttle for some of the intermediate products in glycine decarboxylation. In both animals and plants the glycine cleavage system is loosely attached to the inner membrane of the mitochondria. Mutations in this enzymatic system are linked with glycine encephalopathy. Components Function In plants, animals and bacteria the glycine cleavage system cataly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphoserine Aminotransferase
Phosphoserine transaminase (, ''PSAT'', ''phosphoserine aminotransferase'', ''3-phosphoserine aminotransferase'', ''hydroxypyruvic phosphate-glutamic transaminase'', ''L-phosphoserine aminotransferase'', ''phosphohydroxypyruvate transaminase'', ''phosphohydroxypyruvic-glutamic transaminase'', ''3-O-phospho-L-serine:2-oxoglutarate aminotransferase'', ''SerC'', ''PdxC'', ''3PHP transaminase'') is an enzyme with systematic name ''O-phospho-L-serine:2-oxoglutarate aminotransferase''. This enzyme catalyses the following chemical reaction : (1) O-phospho-L-serine + 2-oxoglutarate \rightleftharpoons 3-phosphonooxypyruvate + L-glutamate : (2) 4-phosphonooxy-L-threonine + 2-oxoglutarate \rightleftharpoons (3R)-3-hydroxy-2-oxo-4-phosphonooxybutanoate + L-glutamate This enzyme is a pyridoxal-phosphate protein. See also * PSAT1 Phosphoserine aminotransferase (PSA) also known as phosphohydroxythreonine aminotransferase (PSAT) is an enzyme that in humans is encoded by the ''PSAT1'' gene. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-phosphoserine Phosphatase
The enzyme phosphoserine phosphatase (EC 3.1.3.3) catalyzes the reaction :''O''-phospho-L(or D)-serine + H2O \rightleftharpoons L(or D)-serine + phosphate This enzyme belongs to the family of hydrolases, specifically those acting on phosphoric monoester bonds. The systematic name is ''O''-phosphoserine phosphohydrolase. This enzyme participates in glycine, serine and threonine metabolism. Structural studies As of late 2007, 12 structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ... have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , and . References * * Boyer, P.D., Lardy, H. and Myrback, K. (Eds.), The Enzymes, 2nd ed., vol. 5, Academic Press, New York, 1961, p. 73-78. * EC 3.1.3 Enzymes of known structure {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3-phosphoglycerate Dehydrogenase
Phosphoglycerate dehydrogenase (PHGDH) is an enzyme that catalyzes the chemical reactions :3-phospho-D-glycerate + NAD+ \rightleftharpoons 3-phosphonooxypyruvate + NADH + H+ :2-hydroxyglutarate + NAD+ \rightleftharpoons 2-oxoglutarate + NADH + H+ The two substrates of this enzyme are 3-phospho-D-glycerate and NAD+, whereas its 3 products are 3-phosphohydroxypyruvate, NADH, and H+ It is also possible that two substrates of this enzyme are 2-hydroxyglutarate and NAD+, whereas its 3 products are 2-oxoglutarate, NADH, and H+. As of 2012, the most widely studied variants of PHGDH are from the '' E. coli'' and '' M. tuberculosis'' genomes. In humans, this enzyme is encoded by the ''PHGDH'' gene. Function 3-Phosphoglycerate dehydrogenase catalyzes the transition of 3-phosphoglycerate into 3-phosphohydroxypyruvate, which is the committed step in the phosphorylated pathway of L-serine biosynthesis. It is also essential in cysteine and glycine synthesis, which lie further do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dihydrofolate Reductase
Dihydrofolate reductase, or DHFR, is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, using NADPH as an electron donor, which can be converted to the kinds of tetrahydrofolate cofactors used in 1-carbon transfer chemistry. In humans, the DHFR enzyme is encoded by the ''DHFR'' gene. It is found in the q11→q22 region of chromosome 5. Bacterial species possess distinct DHFR enzymes (based on their pattern of binding diaminoheterocyclic molecules), but mammalian DHFRs are highly similar. Structure A central eight-stranded beta-pleated sheet makes up the main feature of the polypeptide backbone folding of DHFR. Seven of these strands are parallel and the eighth runs antiparallel. Four alpha helices connect successive beta strands. Residues 9 – 24 are termed "Met20" or "loop 1" and, along with other loops, are part of the major subdomain that surround the active site. The active site is situated in the N-terminal half of the sequence, which includes a conse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sepiapterin Reductase
Sepiapterin reductase is an enzyme that in humans is encoded by the ''SPR'' gene. Function Sepiapterin reductase (7,8-dihydrobiopterin:NADP+ oxidoreductase; EC 1.1.1.153) catalyzes the NADPH-dependent reduction of various carbonyl substances, including derivatives of pteridines, and belongs to a group of enzymes called aldo-keto reductases. SPR plays an important role in the biosynthesis of tetrahydrobiopterin. Reaction Sepiapterin reductase (SPR) catalyzes the chemical reaction L-erythro-7,8-dihydrobiopterin + NADP+ \rightleftharpoons sepiapterin + NADPH + H+ Thus, the two substrates of this enzyme are L-erythro-7,8-dihydrobiopterin and NADP+, whereas its three products are sepiapterin, NADPH, and a single hydrogen ion (H+). This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is 7,8-dihydrobiopterin:NADP+ oxidoreductase. This enzyme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
