- Coenzyme A
Coenzyme A Identifiers CAS number PubChem ChemSpider UNII DrugBank KEGG MeSH ChEMBL Jmol-3D images Image 1 Properties Molecular formula C21H36N7O16P3S Molar mass 767.535 (what is: /?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Coenzyme A (CoA, CoASH, or HSCoA) is a coenzyme, notable for its role in the synthesis and oxidation of fatty acids, and the oxidation of pyruvate in the citric acid cycle. All sequenced genomes encode enzymes that use coenzyme A as a substrate, and around 4% of cellular enzymes use it (or a thioester, such as acetyl-CoA) as a substrate. It is adapted from cysteamine, pantothenate, and adenosine triphosphate.
Coenzyme A is synthesized in a five-step process from pantothenate and cysteine:
- Pantothenate (vitamin B5) is phosphorylated to 4'-phosphopantothenate by the enzyme pantothenate kinase (PanK; CoaA; CoaX)
- A cysteine is added to 4'-phosphopantothenate by the enzyme phosphopantothenoylcysteine synthetase (PPC-DC; CoaB) to form 4'-phospho-N-pantothenoylcysteine (PPC)
- PPC is decarboxylated to 4'-phosphopantetheine by phosphopantothenoylcysteine decarboxylase (CoaC)
- 4'-phosphopantetheine is adenylylated to form dephospho-CoA by the enzyme phosphopantetheine adenylyl transferase (CoaD)
- Finally, dephospho-CoA is phosphorylated using ATP to coenzyme A by the enzyme dephosphocoenzyme A kinase (CoaE).
Since coenzyme A is, in chemical terms, a thiol, it can react with carboxylic acids to form thioesters, thus functioning as an acyl group carrier. It assists in transferring fatty acids from the cytoplasm to mitochondria. A molecule of coenzyme A carrying an acetyl group is also referred to as acetyl-CoA. When it is not attached to an acyl group, it is usually referred to as 'CoASH' or 'HSCoA'.
List of coenzyme A activated acyl groups
- Coumaroyl-CoA (used in flavonoid and stilbenoid biosynthesis)
- Acyl derived from dicarboxylic acids
- Succinyl-CoA (used in heme biosynthesis)
- Hydroxymethylglutaryl-CoA (used in isoprenoid biosynthesis)
- Pimelyl-CoA (used in biotin biosynthesis)
- fatty acyl-CoA (activated form of all fatty acids; only the CoA esters are substrates for important reactions such as mono-, di-, and triacylglycerol synthesis, carnitine palmitoyl transferase, and cholesterol esterification)
- Benzoyl CoA
- Phenylacetyl CoA
- Butyryl CoA
- ^ Matthew Daugherty, Boris Polanuyer, Michael Farrell, Michael Scholle, Athanasios Lykidis, Valérie de Crécy-Lagard and Andrei Osterman (2002). "Complete Reconstitution of the Human Coenzyme A Biosynthetic Pathway via Comparative Genomics". The Journal of Biological Chemistry 277: 21431–21439. doi:10.1074/jbc.M201708200. PMID 11923312.
- ^ Elovson J, Vagelos PR (July 1968). "Acyl carrier protein. X. Acyl carrier protein synthetase". J. Biol. Chem. 243 (13): 3603–11. PMID 4872726.
- ^ Strickland KC, Hoeferlin LA, Oleinik NV, Krupenko NI, Krupenko SA (January 2010). "Acyl carrier protein-specific 4'-phosphopantetheinyl transferase activates 10-formyltetrahydrofolate dehydrogenase". J. Biol. Chem. 285 (3): 1627–33. doi:10.1074/jbc.M109.080556. PMC 2804320. PMID 19933275. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2804320.
- Karl Miller (1998). Beta Oxidation of Fatty Acids. Retrieved May 18, 2005.
- Charles Ophard (2003). Acetyl-CoA Crossroads. Retrieved May 18, 2005.
- Lehninger: Principles of Biochemistry, 4th edition, David L. Nelson, Michael M. Cox
Enzyme cofactors Active forms Base formsvitamins: see vitamins
cof, enz, met
noco, nuvi, sysi/epon, met
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