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Homocitrate Synthase
In enzymology, a homocitrate synthase () is an enzyme that catalyzes the chemical reaction :acetyl-CoA + H2O + 2-oxoglutarate \rightleftharpoons (R)-2-hydroxybutane-1,2,4-tricarboxylate + CoA The 3 substrates of this enzyme are acetyl-CoA, H2O, and 2-oxoglutarate, whereas its two products are (R)-2-hydroxybutane-1,2,4-tricarboxylate and CoA. This enzyme belongs to the family of transferases, specifically those acyltransferases that convert acyl groups into alkyl groups on transfer. The systematic name of this enzyme class is acetyl-CoA:2-oxoglutarate C-acetyltransferase (thioester-hydrolysing, carboxymethyl forming). Other names in common use include 2-hydroxybutane-1,2,4-tricarboxylate 2-oxoglutarate-lyase, (CoA-acetylating), acetyl-coenzyme A:2-ketoglutarate C-acetyl transferase, and homocitrate synthetase. This enzyme participates in lysine biosynthesis and pyruvate metabolism Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymology
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), 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, 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 include Ribozyme, catalytic RNA molecules, also called ribozymes. They are sometimes descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coenzyme A
Coenzyme A (CoA, SHCoA, CoASH) is a coenzyme, notable for its role in the Fatty acid metabolism#Synthesis, synthesis and Fatty acid metabolism#.CE.B2-Oxidation, oxidation of fatty acids, and the oxidation of pyruvic acid, pyruvate in the citric acid cycle. All genomes sequenced to date encode enzymes that use coenzyme A as a Substrate (chemistry), substrate, and around 4% of cellular enzymes use it (or a thioester) as a substrate. In humans, CoA biosynthesis requires cysteine, pantothenic acid, pantothenate (vitamin B5), and adenosine triphosphate (ATP). In acetyl-CoA, its acetyl form, coenzyme A is a highly versatile molecule, serving metabolic functions in both the Anabolism, anabolic and Catabolism, catabolic pathways. Acetyl-CoA is utilised in the post-translational regulation and allosteric regulation of pyruvate dehydrogenase and carboxylase to maintain and support the partition of Pyruvic acid, pyruvate synthesis and degradation. Discovery of structure Coenzyme A was ident ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyruvate Metabolism
Pyruvic acid (CH3COCOOH) is the simplest of the alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate base, CH3COCOO−, is an intermediate in several metabolic pathways throughout the cell. Pyruvic acid can be made from glucose through glycolysis, converted back to carbohydrates (such as glucose) via gluconeogenesis, or converted to fatty acids through a reaction with acetyl-CoA. It can also be used to construct the amino acid alanine and can be converted into ethanol or lactic acid via fermentation. Pyruvic acid supplies energy to cells through the citric acid cycle (also known as the Krebs cycle) when oxygen is present (aerobic respiration), and alternatively ferments to produce lactate when oxygen is lacking. Chemistry In 1834, Théophile-Jules Pelouze distilled tartaric acid and isolated glutaric acid and another unknown organic acid. Jöns Jacob Berzelius characterized this other acid the following year and named pyruvic acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Nomenclature
Chemical nomenclature is a set of rules to generate systematic name#In chemistry, systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC). IUPAC Nomenclature ensures that each compound (and its various isomers) have only one formally accepted name known as the systematic IUPAC name. However, some compounds may have alternative names that are also accepted, known as the preferred IUPAC name which is generally taken from the common name (chemistry), common name of that compound. Preferably, the name should also represent the structure or chemistry of a compound. For example, the main constituent of vinegar, white vinegar is , which is commonly called acetic acid and is also its recommended IUPAC name, but its formal, systematic IUPAC name is ethanoic acid. The IUPAC's rules for naming organic compound, organic and inorganic compounds are contained in two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkyl
In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl group is derived from a cycloalkane by removal of a hydrogen atom from a Ring (chemistry), ring and has the general formula . Typically an alkyl is a part of a larger molecule. In structural formulae, the symbol R is used to designate a generic (unspecified) alkyl group. The smallest alkyl group is methyl, with the formula . Related concepts Alkylation is the addition of alkyl groups to molecules, often by alkylating agents such as Haloalkane, alkyl halides. Alkylating antineoplastic agents are a class of compounds that are used to treat cancer. In such case, the term alkyl is used loosely. For example, nitrogen mustards are well-known alkylating agents, but they are not simple hydrocarbons. In chemistry, alkyl is a group, a substituent, that is attached to ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acyl
In chemistry, an acyl group is a moiety derived by the removal of one or more hydroxyl groups from an oxoacid, including inorganic acids. It contains a double-bonded oxygen atom and an organyl group () or hydrogen in the case of formyl group (). In organic chemistry, the acyl group (IUPAC name alkanoyl if the organyl group is alkyl) is usually derived from a carboxylic acid, in which case it has the formula , where R represents an organyl group or hydrogen. Although the term is almost always applied to organic compounds, acyl groups can in principle be derived from other types of acids such as sulfonic acids and phosphonic acids. In the most common arrangement, acyl groups are attached to a larger molecular fragment, in which case the carbon and oxygen atoms are linked by a double bond. Reactivity trends There are five main types of acyl derivatives. Acid halides are the most reactive towards nucleophiles, followed by anhydrides, esters, and amides. Carboxylate ions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acyltransferases
Acyltransferase is a type of transferase enzyme that acts upon acyl groups. Examples include: * Glycerol-3-phosphate acyltransferases * Glyceronephosphate O-acyltransferase * Lecithin-cholesterol acyltransferase *Long-chain-alcohol O-fatty-acyltransferase See also * Acetyltransferase An acetyltransferase (also referred to as a transacetylase) is any of a class of transferase enzymes that transfers an acetyl group in a reaction called acetylation. In biological organisms, post-translational modification of a protein via acetyl ... External links * Transferases EC 2.3 {{2.3-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transferase
In biochemistry, a transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor). They are involved in hundreds of different biochemical pathways throughout biology, and are integral to some of life's most important processes. Transferases are involved in myriad reactions in the cell. Three examples of these reactions are the activity of coenzyme A (CoA) transferase, which transfers thiol esters, the action of N-acetyltransferase, which is part of the pathway that metabolizes tryptophan, and the regulation of pyruvate dehydrogenase (PDH), which converts pyruvate to acetyl CoA. Transferases are also utilized during translation. In this case, an amino acid chain is the functional group transferred by a peptidyl transferase. The transfer involves the removal of the growing amino acid chain from the tRNA molecule in the A-site of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
(R)-2-hydroxybutane-1,2,4-tricarboxylate
Homocitric acid is an organic compound with the formula HOC(CO2H)(CH2CO2H)(C2H4CO2H). This tricarboxylic acid occurs naturally as a component of the iron-molybdenum cofactor of certain nitrogenase proteins. Biochemists often refer to this cofactor as homocitrate, which is the conjugate bases that predominate in neutral aqueous solutions of this species. The molecule is related to citric acid by the addition of one methylene unit, hence the prefix "homo." Unlike citric acid, homocitric acid is chiral. The acid exists in equilibrium with the lactone. : See also * Homoisocitric acid Homoisocitric acid is an isomer of homocitric acid in which the hydroxyl is on the 2 position. It is an intermediate in the α-aminoadipate pathway of lysine biosynthesis where it is produced by homocitrate synthase and is a substrate for homo ... References Alpha hydroxy acids Chelating agents Tricarboxylic acids {{acid-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Product (chemistry)
Products are the species formed from chemical reactions. During a chemical reaction, reactants are transformed into products after passing through a high energy transition state. This process results in the consumption of the reactants. It can be a spontaneous reaction or mediated by catalysts which lower the energy of the transition state, and by solvents which provide the chemical environment necessary for the reaction to take place. When represented in chemical equations, products are by convention drawn on the right-hand side, even in the case of reversible reactions. The properties of products such as their energies help determine several characteristics of a chemical reaction, such as whether the reaction is exergonic or endergonic. Additionally, the properties of a product can make it easier to extract and purify following a chemical reaction, especially if the product has a different state of matter than the reactants. Spontaneous reaction : R \rightarrow P *W ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
