|
Acetyl-CoA Hydrolase
The enzyme acetyl-CoA hydrolase (EC 3.1.2.1) catalyzes the reaction acetyl-CoA + H2O \rightleftharpoons CoA + acetate This enzyme belongs to the family of hydrolases, specifically those acting on thioester bonds. The systematic name is CoA thiol esterase. This enzyme participates in pyruvate metabolism. Structural studies As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code . See also *Acetyl-CoA synthetase Acetyl-CoA synthetase (ACS) or Acetate—CoA ligase is an enzyme () involved in metabolism of acetate. It is in the ligase class of enzymes, meaning that it catalyzes the formation of a new chemical bond between two large molecules. Reaction The ... and ACSS2, enzymes that perform the reverse reaction using ATP References * EC 3.1.2 Enzymes of known structure {{3.1-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalysis
Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quickly, very small amounts of catalyst often suffice; mixing, surface area, and temperature are important factors in reaction rate. Catalysts generally react with one or more reactants to form intermediates that subsequently give the final reaction product, in the process of regenerating the catalyst. Catalysis may be classified as either homogeneous, whose components are dispersed in the same phase (usually gaseous or liquid) as the reactant, or heterogeneous, whose components are not in the same phase. Enzymes and other biocatalysts are often considered as a third category. Catalysis is ubiquitous in chemical industry of all kinds. Estimates are that 90% of all commercially produced chemical products involve catalysts at some s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl-CoA Hydrolase
The enzyme acetyl-CoA hydrolase (EC 3.1.2.1) catalyzes the reaction acetyl-CoA + H2O \rightleftharpoons CoA + acetate This enzyme belongs to the family of hydrolases, specifically those acting on thioester bonds. The systematic name is CoA thiol esterase. This enzyme participates in pyruvate metabolism. Structural studies As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code . See also *Acetyl-CoA synthetase Acetyl-CoA synthetase (ACS) or Acetate—CoA ligase is an enzyme () involved in metabolism of acetate. It is in the ligase class of enzymes, meaning that it catalyzes the formation of a new chemical bond between two large molecules. Reaction The ... and ACSS2, enzymes that perform the reverse reaction using ATP References * EC 3.1.2 Enzymes of known structure {{3.1-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolase
Hydrolase is a class of enzyme that commonly perform as biochemical catalysts that use water to break a chemical bond, which typically results in dividing a larger molecule into smaller molecules. Some common examples of hydrolase enzymes are esterases including lipases, phosphatases, glycosidases, peptidases, and nucleosidases. Esterases cleave ester bonds in lipids and phosphatases cleave phosphate groups off molecules. An example of crucial esterase is acetylcholine esterase, which assists in transforming the neuron impulse into the acetate group after the hydrolase breaks the acetylcholine into choline and acetic acid. Acetic acid is an important metabolite in the body and a critical intermediate for other reactions such as glycolysis. Lipases hydrolyze glycerides. Glycosidases cleave sugar molecules off carbohydrates and peptidases hydrolyze peptide bonds. Nucleosidases hydrolyze the bonds of nucleotides. Hydrolase enzymes are important for the body because they have degra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thioester
In organic chemistry, thioesters are organosulfur compounds with the functional group . They are analogous to carboxylate esters () with the sulfur in the thioester playing the role of the linking oxygen in the carboxylate ester, as implied by the ''thio-'' prefix. They are the product of esterification between a carboxylic acid () and a thiol (). In biochemistry, the best-known thioesters are derivatives of coenzyme A, e.g., acetyl-CoA.Matthys J. Janssen "Carboxylic Acids and Esters" in PATAI's Chemistry of Functional Groups: Carboxylic Acids and Esters, Saul Patai, Ed. John Wiley, 1969, New York: pp. 705–764. Synthesis The most typical route to thioester involves the reaction of an acid chloride with an alkali metal salt of a thiol: :RSNa + R'COCl -> R'COSR + NaCl Another common route entails the displacement of halides by the alkali metal salt of a thiocarboxylic acid. For example, thioacetate esters are commonly prepared by alkylation of potassium thioacetate: :CH3COSK + ... [...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 A conjugate acid, within the Brønsted–Lowry acid–base theory, is a chemical compound formed when an acid donates a proton () to a base—in other words, it is a base with a hydrogen ion added to it, as in the reverse reaction it loses a ..., 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 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 cell (biology), cells through the citric acid cycle (also known as the Krebs cycle) when oxygen is present (aerobic respiration), and alternatively lactic acid fermen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tertiary Structure
Protein tertiary structure is the three dimensional shape of a protein. The tertiary structure will have a single polypeptide chain "backbone" with one or more protein secondary structures, the protein domains. Amino acid side chains may interact and bond in a number of ways. The interactions and bonds of side chains within a particular protein determine its tertiary structure. The protein tertiary structure is defined by its atomic coordinates. These coordinates may refer either to a protein domain or to the entire tertiary structure.Branden C. and Tooze J. "Introduction to Protein Structure" Garland Publishing, New York. 1990 and 1991. A number of tertiary structures may fold into a quaternary structure.Kyte, J. "Structure in Protein Chemistry." Garland Publishing, New York. 1995. History The science of the tertiary structure of proteins has progressed from one of hypothesis to one of detailed definition. Although Emil Fischer had suggested proteins were made of polypept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Data Bank
The Protein Data Bank (PDB) is a database for the three-dimensional structural data of large biological molecules, such as proteins and nucleic acids. The data, typically obtained by X-ray crystallography, NMR spectroscopy, or, increasingly, cryo-electron microscopy, and submitted by biologists and biochemists from around the world, are freely accessible on the Internet via the websites of its member organisations (PDBe, PDBj, RCSB, and BMRB). The PDB is overseen by an organization called the Worldwide Protein Data Bank, wwPDB. The PDB is a key in areas of structural biology, such as structural genomics. Most major scientific journals and some funding agencies now require scientists to submit their structure data to the PDB. Many other databases use protein structures deposited in the PDB. For example, SCOP and CATH classify protein structures, while PDBsum provides a graphic overview of PDB entries using information from other sources, such as Gene ontology. History Two force ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetyl-CoA Synthetase
Acetyl-CoA synthetase (ACS) or Acetate—CoA ligase is an enzyme () involved in metabolism of acetate. It is in the ligase class of enzymes, meaning that it catalyzes the formation of a new chemical bond between two large molecules. Reaction The two molecules joined together that make up Acetyl CoA are acetate and coenzyme A (CoA). The complete reaction with all the substrates and products included is: : ATP + Acetate + CoA AMP + Pyrophosphate + Acetyl-CoA Once acetyl-CoA is formed it can be used in the TCA cycle in aerobic respiration to produce energy and electron carriers. This is an alternate method to starting the cycle, as the more common way is producing acetyl-CoA from pyruvate through the pyruvate dehydrogenase complex. The enzyme's activity takes place in the mitochondrial matrix so that the products are in the proper place to be used in the following metabolic steps. Acetyl Co-A can also be used in fatty acid synthesis, and a common function of the synthetase ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACSS2
Acyl-coenzyme A synthetase short-chain family member 2 is an enzyme that in humans is encoded by the ''ACSS2'' gene. Function This gene encodes a cytosolic enzyme that catalyzes the activation of acetate for use in lipid synthesis and energy generation. The protein acts as a monomer and produces acetyl- CoA from acetate in a reaction that requires ATP. It is also essential for the production of Crotonyl-CoA which activates its target genes by crotonylation of histone tails. Expression of this gene is regulated by sterol regulatory element-binding proteins, transcription factors that activate genes required for the synthesis of cholesterol and unsaturated fatty acids. Two transcript variants encoding different isoform A protein isoform, or "protein variant", is a member of a set of highly similar proteins that originate from a single gene or gene family and are the result of genetic differences. While many perform the same or similar biological roles, some isof ...s have bee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
