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Cysteine Sulfinic Acid
Cysteine sulfinic acid is the organic compound with the nominal formula HO2SCH2CH(NH2)CO2H . It is a rare example of an amino acid bearing a sulfinic acid functional group. It is a white solid that is soluble in water. Like most natural amino acids, it is chiral, only the d-enantiomer occurs in nature, and it exists as the zwitterion at neutral pH. It is an intermediate in cysteine metabolism. It is not a coded amino acid, but is produced post-translationally. Peptides containing the cysteine sulfinic acid residue are substrates for cysteine sulfinic acid reductase. Cysteine sulfinic acid is derived from cysteine. Cysteine is formed from cystathionine via the cystathionine gamma-lyase enzyme, and is either broken down by cysteine lyase or cystathionine gamma-lyase or enters the cysteine sulfinic acid pathway where it is oxidized by cysteine dioxygenase to form cysteine sulfinic acid. Cysteine sulfinic acid, in turn, is decarboxylated by sulfinoalanine decarboxylase to form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon- hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, hydrogen cyanide), are not classified as organic compounds and are considered inorganic. Other than those just named, little consensus exists among chemists on precisely which carbon-containing compounds are excluded, making any rigorous definition of an organic compound elusive. Although organic compounds make up only a small percentage of Earth's crust, they are of central importance because all known life is based on organic compounds. Livin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine Lyase
The enzyme cysteine lyase (EC 4.4.1.10) catalyzes the chemical reaction :L-cysteine + sulfite \rightleftharpoons L-cysteate + hydrogen sulfide This enzyme belongs to the family of lyases, specifically the class of carbon-sulfur lyases. The systematic name of this enzyme class is L-cysteine hydrogen-sulfide-lyase (adding sulfite; L-cysteate-forming). Other names in common use include cysteine (sulfite) lyase, and L-cysteine hydrogen-sulfide-lyase (adding sulfite). This enzyme participates in cysteine and taurine metabolism. It employs one cofactor, pyridoxal phosphate. Evolution Genes encoding cysteine lyase (CL) originated around 300 million years ago by a tandem gene duplication and neofunctionalization of cystathionine β-lyase (CBS) shortly after the split of mammalian and reptilian lineages. CL genes are found only in ''Sauropsida Sauropsida ("lizard faces") is a clade of amniotes, broadly equivalent to the class Reptilia. Sauropsida is the sister taxon to Synap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degradation Of Cysteine To Taurine
Degradation may refer to: Science * Degradation (geology), lowering of a fluvial surface by erosion * Degradation (telecommunications), of an electronic signal * Biodegradation of organic substances by living organisms * Environmental degradation in ecology * Land degradation, a process in which the value of the biophysical environment is affected by a combination of human-induced processes acting upon the land * Polymer degradation, as plastics age Other * Elegant degradation, gradual rather than sudden * Graceful degradation, in a fault-tolerant system * Degradation (knighthood), revocation of knighthood * Cashiering, whereby a military officer is dismissed for misconduct * Reduction in rank, whereby a military officer is reduced to a lower rank for misconduct * Degradation, the former ceremony of defrocking a disgraced priest * ''Degradation'', a song by the Violent Femmes, from '' Add It Up (1981–1993)'' See also * ''Dégradé ''Dégradé'' ( ar, ديچراد� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrile Hydratase
Nitrile hydratases (NHases; ) are mononuclear iron or non-corrinoid cobalt enzymes that catalyse the hydration of diverse nitriles to their corresponding amides R-C≡N + H2O → R-C(O)NH2 Metal cofactor In biochemistry, cobalt is in general found in a corrin ring, such as in vitamin B12. Nitrile hydratase is one of the rare enzyme types that use cobalt in a non-corrinoid manner. The mechanism by which the cobalt is transported to NHase without causing toxicity is unclear, although a cobalt permease has been identified, which transports cobalt across the cell membrane. The identity of the metal in the active site of a nitrile hydratase can be predicted by analysis of the sequence data of the alpha subunit in the region where the metal is bound. The presence of the amino acid sequence VCTLC indicates a Co-centred NHase and the presence of VCSLC indicates Fe-centred NHase. Metabolic pathway Nitrile hydratase and amidase are two hydrating and hydrolytic enzymes responsibl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotaurine Dehydrogenase
In enzymology, a hypotaurine dehydrogenase () is an enzyme that catalyzes the chemical reaction :hypotaurine + H2O + NAD+ \rightleftharpoons taurine + NADH + H+ The 3 substrates of this enzyme are hypotaurine, H2O, and NAD+, whereas its 3 products are taurine, NADH, and H+. This enzyme belongs to the family of oxidoreductases, specifically those acting on a sulfur group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is hypotaurine:NAD+ oxidoreductase. This enzyme participates in taurine and hypotaurine metabolism. It has 2 cofactors: heme, and Molybdenum Molybdenum is a chemical element with the symbol Mo and atomic number 42 which is located in period 5 and group 6. The name is from Neo-Latin ''molybdaenum'', which is based on Ancient Greek ', meaning lead, since its ores were confused with le .... References * EC 1.8.1 NADH-dependent enzymes Heme enzymes Molybdenum enzymes Enzymes of unknown structure {{1.8- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypotaurine
Hypotaurine is a sulfinic acid that is an intermediate in the biosynthesis of taurine. Like taurine, it also acts as an endogenous neurotransmitter via action on the glycine receptors. It is an osmolyte with antioxidant properties. Hypotaurine is derived from cysteine (and homocysteine). In mammals, the biosynthesis of hypotaurine from cysteine occurs in the pancreas. In the cysteine sulfinic acid pathway, cysteine is first oxidized to its sulfinic acid, catalyzed by the enzyme cysteine dioxygenase. Cysteine sulfinic acid, in turn, is decarboxylated by sulfinoalanine decarboxylase The enzyme sulfinoalanine decarboxylase () catalyzes the chemical reaction :3-sulfino-L-alanine \rightleftharpoons hypotaurine + CO2 Hence, this enzyme has one substrate, 3-sulfino-L-alanine (also known as Cysteine sulfinic acid), and two pro ... to form hypotaurine. Hypotaurine is enzymatically oxidized to yield taurine by hypotaurine dehydrogenase. References Amines Sulfinic acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfinoalanine Decarboxylase
The enzyme sulfinoalanine decarboxylase () catalyzes the chemical reaction :3-sulfino-L-alanine \rightleftharpoons hypotaurine + CO2 Hence, this enzyme has one substrate, 3-sulfino-L-alanine (also known as Cysteine sulfinic acid), and two products, hypotaurine and CO2. This enzyme belongs to the family of lyases, specifically the carboxy-lyases, which cleave carbon-carbon bonds. The systematic name of this enzyme class is 3-sulfino-L-alanine carboxy-lyase (hypotaurine-forming). Other names in common use include cysteine-sulfinate decarboxylase, L-cysteinesulfinic acid decarboxylase, cysteine-sulfinate decarboxylase, CADCase/CSADCase, CSAD, cysteic decarboxylase, cysteinesulfinic acid decarboxylase, cysteinesulfinate decarboxylase, sulfoalanine decarboxylase, and 3-sulfino-L-alanine carboxy-lyase. This enzyme participates in taurine metabolism. It employs one cofactor, pyridoxal phosphate Pyridoxal phosphate (PLP, pyridoxal 5'- phosphate, P5P), the active form of vit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine Dioxygenase
Cysteine dioxygenase (CDO) is a non-heme iron enzyme that catalyzes the conversion of L-cysteine to cysteine sulfinic acid (cysteine sulfinate). CDO plays an important role in cysteine catabolism, regulating intracellular levels of cysteine and responding changes in cysteine availability. As such, CDO is highly regulated and undergoes large changes in concentration and efficiency. It oxidizes cysteine to the corresponding sulfinic acid by activation of dioxygen, although the exact mechanism of the reaction is still unclear. In addition to being found in mammals, CDO also exists in some yeast and bacteria, although the exact function is still unknown. CDO has been implicated in various neurodegenerative diseases and cancers, which is likely related to cysteine toxicity. Function CDO is responsible for the first major step in metabolism of cysteine. CDO oxidizes to cysteine sulfinic acid (which exists predominantly in the anionic sulfinate form ''in vivo''). Overall, CDO catalyzes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystathionine Gamma-lyase
The enzyme cystathionine γ-lyase (EC 4.4.1.1, CTH or CSE; also cystathionase; systematic name L-cystathionine cysteine-lyase (deaminating; 2-oxobutanoate-forming)) breaks down cystathionine into cysteine, 2-oxobutanoate ( α-ketobutyrate), and ammonia: :L-cystathionine + H2O = L-cysteine + 2-oxobutanoate + NH3 (overall reaction) ::(1a) L-cystathionine = L-cysteine + 2-aminobut-2-enoate ::(1b) 2-aminobut-2-enoate = 2-iminobutanoate (spontaneous) ::(1c) 2-iminobutanoate + H2O = 2-oxobutanoate + NH3 (spontaneous) Pyridoxal phosphate is a prosthetic group of this enzyme. Cystathionine γ-lyase also catalyses the following elimination reactions: * L- homoserine to form H2O, NH3 and 2-oxobutanoate * L-cystine, producing thiocysteine, pyruvate and NH3 * L-cysteine producing pyruvate, NH3 and H2S In some bacteria and mammals, including humans, this enzyme takes part in generating hydrogen sulfide. Hydrogen sulfide is one of a few gases that was recently discovered to have a role ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid ''residues'' form the second-largest component ( water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cystathionine
Cystathionine is an intermediate in the synthesis of cysteine. Cystathionine is produced by the transsulfuration pathway which converts homocysteine into cystathionine. Cystathionine is then used by the enzymes cystathionine gamma-lyase (CTH), cysteine dioxygenase (CDO), and sulfinoalanine decarboxylase to produce hypotaurine and then taurine. Alternately, the cysteine from the cystathionine gamma-lyase can be used by the enzymes glutamate–cysteine ligase (GCL) and glutathione synthetase (GSS) to produce glutathione. An excess of cystathionine in the urine is called cystathioninuria. Biosynthetically, cystathionine is generated from homocysteine and serine by cystathionine beta synthase (upper reaction in the diagram below). It is then cleaved into cysteine and α-ketobutyrate by cystathionine gamma-lyase The enzyme cystathionine γ-lyase (EC 4.4.1.1, CTH or CSE; also cystathionase; systematic name L-cystathionine cysteine-lyase (deaminating; 2-oxobutanoate-forming)) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cysteine
Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile. When present as a deprotonated catalytic residue, sometimes the symbol Cyz is used. The deprotonated form can generally be described by the symbol Cym as well. The thiol is susceptible to oxidation to give the disulfide derivative cystine, which serves an important structural role in many proteins. In this case, the symbol Cyx is sometimes used. When used as a food additive, it has the E number E920. Cysteine is encoded by the codons UGU and UGC. The sulfur-containing amino acids cysteine and methionine are more easily oxidized than the other amino acids. Structure Like other amino acids (not as a residue of a protein), cysteine exists as a zwitterion. Cysteine has chirality in the older / notation based on homology to - and -glyceraldehyde. In the newer ''R''/''S'' system of de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
