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Amine Oxidase
An amine oxidase is an enzyme that catalyzes the oxidative cleavage of alkylamines into aldehydes and ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous was ...: :RCH2NH2 + H2O + O2 \rightleftharpoons RCHO + NH3 + H2O2 Amine oxidases are divided into two subfamilies based on the cofactor they contain: References External links * {{oxidoreductase-stub EC 1.4.3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. Almost all metabolic processes in the cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are catalytic RNA molecules, called ribozymes. Enzymes' specificity comes from their unique three-dimensional structures. Like all catalysts, enzymes increase the reaction ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Primary-amine Oxidase
Primary-amine oxidase, also known as semicarbazide-sensitive amine oxidase (SSAO), is an enzyme () with the systematic name ''primary-amine:oxygen oxidoreductase (deaminating)''. This enzyme catalyses the following chemical reaction : RCH2NH2 + H2O + O2 \rightleftharpoons RCHO + NH3 + H2O2 These enzymes are copper quinoproteins (2,4,5-trihydroxyphenylalanine quinone). Like monoamine oxidase (MAO), SSAO can deaminate short-chain primary amines, but is insensitive to MAO inhibitors. Semicarbazide inhibits the enzyme, in addition to other hydrazines, hydroxylamine and propargylamine. However, hydrazines are weak inhibitors and stronger inhibitors have been developed. SSAO is found in the smooth muscle of blood vessels and various other tissues. The physiological function of SSAO is not well understood. Development of blood vessels, lipolysis regulation, and detoxication are suggested. It may function as a scavenger enzyme to assist MAO. However, the oxidation process generates har ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MAOA
Monoamine oxidase A, also known as MAO-A, is an enzyme that in humans is encoded by the ''MAOA'' gene. This gene is one of two neighboring gene family members that encode mitochondrial enzymes which catalyze the oxidative deamination of amines, such as dopamine, norepinephrine, and serotonin. A mutation of this gene results in Brunner syndrome. This gene has also been associated with a variety of other psychiatric disorders, including antisocial behavior. Alternatively spliced transcript variants encoding multiple isoforms have been observed. Structures Gene Monoamine oxidase A, also known as MAO-A, is an enzyme that in humans is encoded by the ''MAOA'' gene. The promoter of ''MAOA'' contains conserved binding sites for Sp1, GATA2, and TBP. This gene is adjacent to a related gene (''MAOB'') on the opposite strand of the X chromosome. In humans, there is a 30-base repeat sequence repeated several different numbers of times in the promoter region of MAO-A. There are 2R ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoamine Oxidase
Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The first such enzyme was discovered in 1928 by Mary Bernheim in the liver and was named tyramine oxidase. The MAOs belong to the protein family of flavin-containing amine oxidoreductases. MAOs are important in the breakdown of monoamines ingested in food, and also serve to inactivate monoamine neurotransmitters. Because of the latter, they are involved in a number of psychiatric and neurological diseases, some of which can be treated with monoamine oxidase inhibitors (MAOIs) which block the action of MAOs. Subtypes and tissue distribution In humans there are two types of MAO: MAO-A and MAO-B. * Both are found in neurons and astroglia. * Outside the central nervous system: ** MAO-A is also found in the liver, pulmonary vascular endothelium, gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AOC1
Diamine oxidase (DAO), also known "amine oxidase, copper-containing, 1" (AOC1), formerly called histaminase, is an enzyme () involved in the metabolism, oxidation, and inactivation of histamine and other polyamines such as putrescine or spermidine in animals. It belongs to the amine oxidase (copper-containing) (AOC) family of amine oxidase enzymes. In humans, DAO it is encoded by ''AOC1'' gene. The highest levels of DAO expression are observed in the digestive tract and the placenta. In humans, a certain subtype of cells of the placenta, namely the extravillous trophoblasts, express the enzyme and secrete it into the blood stream of a pregnant woman. Lowered diamine oxidase values in maternal blood in early pregnancy might be an indication for trophoblast-related pregnancy disorders like early-onset preeclampsia. Normally the enzyme is not or only very scarcely present in the blood circulation of humans, but it increases vastly in pregnant women suggesting a protective mechanism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diamine Oxidase
Diamine oxidase (DAO), also known "amine oxidase, copper-containing, 1" (AOC1), formerly called histaminase, is an enzyme () involved in the metabolism, oxidation, and inactivation of histamine and other polyamines such as putrescine or spermidine in animals. It belongs to the amine oxidase (copper-containing) (AOC) family of amine oxidase enzymes. In humans, DAO it is encoded by ''AOC1'' gene. The highest levels of DAO expression are observed in the digestive tract and the placenta. In humans, a certain subtype of cells of the placenta, namely the extravillous trophoblasts, express the enzyme and secrete it into the blood stream of a pregnant woman. Lowered diamine oxidase values in maternal blood in early pregnancy might be an indication for trophoblast-related pregnancy disorders like early-onset preeclampsia. Normally the enzyme is not or only very scarcely present in the blood circulation of humans, but it increases vastly in pregnant women suggesting a protective mechanis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AOC3
Amine oxidase, copper containing 3 (AOC3), also known as vascular adhesion protein (VAP-1) and HPAO is an enzyme that in humans is encoded by the AOC3 gene on chromosome 17. This protein is a member of the semicarbazide-sensitive amine oxidase (SSAO; aka primary amine oxidase) family of enzymes and is associated with many vascular diseases. Structure VAP-1 is a type 1 membrane-bound glycoprotein that has a distal adhesion domain and an enzymatically active amine oxidase site outside of the membrane. The AOC3 gene is mapped onto 17q21 and has an exon count of 6. Function Amine oxidases are a family of enzymes that catalyze the oxidation of various endogenous amines, including histamine or dopamine. VAP-1 constitutes the copper dependent class of amine oxidases, such as lysyl oxidase or lysine demethylase, and is one of the four known in humans. The other class is flavin dependent such as monoamine oxidase (MAO) A and B. VAP-1, in particular, catalyzes the oxidative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AOC2
Amine oxidase, copper containing 2 (AOC2) is a protein that in humans is encoded by the ''AOC2'' gene. The protein is a copper-containing primary amine oxidase enzyme. Function Copper amine oxidases catalyze the oxidative conversion of amines to aldehydes and ammonia in the presence of copper and quinone cofactor. This gene shows high sequence similarity to copper amine oxidases from various species ranging from bacteria to mammals. The protein contains several conserved motifs including the active site of amine oxidases and the histidine residues that likely bind copper. It may be a critical modulator of signal transmission in retina, possibly by degrading the biogenic amines dopamine, histamine, and putrescine Putrescine is an organic compound with the formula (CH2)4(NH2)2. It is a colorless solid that melts near room temperature. It is classified as a diamine. Together with cadaverine, it is largely responsible for the foul odor of putrefying flesh, .... This gene may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysyl Oxidase
Lysyl oxidase (LOX), also known as protein-lysine 6-oxidase, is an enzyme that, in humans, is encoded by the ''LOX'' gene. It catalyzes the conversion of lysine molecules into highly reactive aldehydes that form cross-links in extracellular matrix proteins. Its inhibition can cause osteolathyrism, but, at the same time, its upregulation by tumor cells may promote metastasis of the existing tumor, causing it to become malignant and cancerous. Structure In the yeast strain ''Pichia pastoris'', lysyl oxidase constitutes a homodimeric structure. Each monomer consists of an active site that includes a Cu(II) atom coordinated with three histidine residues as well as 2,4,5-trihydroxyphenalanine quinone (TPQ), a crucial cofactor. In humans, the LOX gene is located on chromosome 5 q23.3-31.2. The DNA sequence encodes a polypeptide of 417 amino acids, the first 21 residues of which constitute a signal peptide, with a weight of approximately 32 kDa. The carboxyterminus contains the act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxidative Cleavage
Organic reductions or organic oxidations or organic redox reactions are redox reactions that take place with organic compounds. In organic chemistry oxidations and reductions are different from ordinary redox reactions, because many reactions carry the name but do not actually involve electron transfer.March Jerry; (1985). Advanced Organic Chemistry reactions, mechanisms and structure (3rd ed.). New York: John Wiley & Sons, inc. Instead the relevant criterion for organic oxidation is gain of oxygen and/or loss of hydrogen, respectively.''Organic Redox Systems: Synthesis, Properties, and Applications'', Tohru Nishinaga 2016 Simple functional groups can be arranged in order of increasing oxidation state. The oxidation numbers are only an approximation: When methane is oxidized to carbon dioxide its oxidation number changes from −4 to +4. Classical reductions include alkene reduction to alkanes and classical oxidations include oxidation of alcohols to aldehydes. In oxidations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lysyl Oxidase
Lysyl oxidase (LOX), also known as protein-lysine 6-oxidase, is an enzyme that, in humans, is encoded by the ''LOX'' gene. It catalyzes the conversion of lysine molecules into highly reactive aldehydes that form cross-links in extracellular matrix proteins. Its inhibition can cause osteolathyrism, but, at the same time, its upregulation by tumor cells may promote metastasis of the existing tumor, causing it to become malignant and cancerous. Structure In the yeast strain ''Pichia pastoris'', lysyl oxidase constitutes a homodimeric structure. Each monomer consists of an active site that includes a Cu(II) atom coordinated with three histidine residues as well as 2,4,5-trihydroxyphenalanine quinone (TPQ), a crucial cofactor. In humans, the LOX gene is located on chromosome 5 q23.3-31.2. The DNA sequence encodes a polypeptide of 417 amino acids, the first 21 residues of which constitute a signal peptide, with a weight of approximately 32 kDa. The carboxyterminus contains the act ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amine Oxidase (copper-containing)
Amine oxidase (copper-containing) (AOC) ( and ; formerly ) is a family of amine oxidase enzymes which includes both primary-amine oxidase and diamine oxidase; these enzymes catalyze the oxidation of a wide range of biogenic amines including many neurotransmitters, histamine and xenobiotic amines. They act as a disulphide-linked homodimer. They catalyse the oxidation of primary amines to aldehydes, with the subsequent release of ammonia and hydrogen peroxide, which requires one copper ion per subunit and topaquinone as cofactor: :RCH2NH2 + H2O + O2 \rightleftharpoons RCHO + NH3 + H2O2 The 3 substrates of this enzyme are primary amines (RCH2NH2), H2O, and O2, whereas its 3 products are RCHO, NH3, and H2O2. Copper-containing amine oxidases are found in bacteria, fungi, plants and animals. In prokaryotes, the enzyme enables various amine substrates to be used as sources of carbon and nitrogen. This enzyme belongs to oxidoreductases, specifically those acting on the CH-NH2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
