Coenzyme A
| Coenzyme A | |
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| Identifiers | |
| CAS number | 85-61-0  |
| PubChem | 6816 |
| ChemSpider | 6557 |
| UNII | SAA04E81UX |
| DrugBank | DB01992 |
| KEGG | C00010 |
| MeSH | Coenzyme+A |
| ChEBI | CHEBI:15346  |
| ChEMBL | CHEMBL1213327 |
| Jmol-3D images | Image 1 |
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| Properties | |
| Molecular formula | C21H36N7O16P3S |
| Molar mass | 767.535 |
 (verify) (what is:  / ?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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| Infobox references | |
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.[1] It is adapted from cysteamine, pantothenate, and adenosine triphosphate.
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[edit] Biosynthesis
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).
[edit] Discovery of structure
The structure of co-enzyme A was defined in the early 1950s at the Lister Institute, London, together with other workers at Harvard Medical School and Massachusetts General Hospital.[2]
[edit] Function
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'.
Coenzyme A is also the source of the phosphopantetheine group that is added as a prosthetic group to proteins such as acyl carrier protein and formyltetrahydrofolate dehydrogenase.[3][4]
[edit] List of coenzyme A-activated acyl groups
- Acetyl-CoA
- Propionyl-CoA
- Acetoacetyl-CoA
- Coumaroyl-CoA (used in flavonoid and stilbenoid biosynthesis)
- Acyl derived from dicarboxylic acids
- Malonyl-CoA
- 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
[edit] Additional images
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Coenzyme A
[edit] References
- ^ 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.
- ^ Baddiley, J.; Thain, E. M.; Novelli, G. D.; Lipmann, F. (1953). "Structure of Coenzyme A"Nature 171 (4341): 76. doi:10.1038/171076a0.
- ^ 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.
[edit] Bibliography
- Karl Miller (1998). Beta Oxidation of Fatty Acids. Retrieved May 18, 2005.
- Charles Ophard (2003). Acetyl-CoA Crossroads. Retrieved May 18, 2005.
- Nelson, David L.; Cox, Michael M. (2005). Lehninger: Principles of Biochemistry (4th ed.). New York: W.H. Freeman. ISBN 0716743396.
- Overview of Fatty Acid Oxidation Reactions
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