Acetyl-CoA
This article has an unclear citation style. The reason given is: Multiple page-numbers in a single ref that is used multiple times: unclear which supports which. Some ISBN might be for wrong edition of the book. Need page-numbers for refs to whole broad-coverage textbooks. (August 2017) |
Names | |
---|---|
Preferred IUPAC name
O1-{(3R)-4-[(3-{[2-(Acetylsulfanyl)ethyl]amino}-3-oxopropyl)amino]-3-hydroxy-2,2-dimethyl-4-oxobutyl} O3-{[(2R,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-4-hydroxy-3-(phosphonooxy)oxolan-2-yl]methyl} dihydrogen diphosphate | |
Identifiers | |
| |
3D model (
JSmol ) |
|
ChEBI | |
ChemSpider | |
ECHA InfoCard
|
100.000.719 |
IUPHAR/BPS |
|
KEGG | |
MeSH | Acetyl+Coenzyme+A |
PubChem CID
|
|
UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
Properties | |
C23H38N7O17P3S | |
Molar mass | 809.57 g·mol−1 |
UV-vis (λmax) | 260 nm; 232 nm[1] |
Absorbance | ε232 on thioester hydrolysis = −4.5 mM−1 cm−1[1]
|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|
Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many
CoA is acetylated to acetyl-CoA by the breakdown of
Role
Acetyl-CoA is a
In addition, acetyl-CoA is a precursor for the biosynthesis of various acetyl-chemicals, acting as an intermediate to transfer an acetyl group during the biosynthesis of those acetyl-chemicals. Acetyl-CoA is also involved in the regulation of various cellular mechanisms by providing acetyl groups to target amino acid residues for post-translational acetylation reactions of proteins.[7]
Biosynthesis
The acetylation of CoA is determined by the carbon sources.[8][9]
Extramitochondrial
- At high
- At low glucose levels:
- CoA is acetylated using acetate by acetyl-CoA synthetase (ACS), also coupled with ATP hydrolysis.[12]
- Ethanol also serves as a carbon source for acetylation of CoA utilizing the enzyme alcohol dehydrogenase.[13]
- Degradation of branched-chain acetoacetate.[14][page needed]
Intramitochondrial
- At high glucose levels, acetyl-CoA is produced through disproportionates pyruvate into acetyl-CoA and formic acid.
- At low glucose levels, the production of acetyl-CoA is linked to oxidation and thiolysis catalyzed by four respective enzymes, namely acyl-CoA dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and thiolase. The cycle produces a new fatty acid chain with two fewer carbons and acetyl-CoA as a byproduct.[16]
Functions
Intermediates in various pathways
- In cellular respiration
- Citric acid cycle:
- Through a series of chemical reactions, stored energy is released through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins into adenosine triphosphate (ATP) and carbon dioxide.
- Fatty acid metabolism
- Acetyl-CoA is produced by the breakdown of both lipids (by β-oxidation). It then enters the citric acid cycle in the mitochondrion by combining with oxaloacetate to form citrate.[17][18]
- Two acetyl-CoA molecules condense to form ketone bodies (as they are not "bodies" at all, but water-soluble chemical substances). The ketone bodies are released by the liver into the blood. All cells with mitochondria can take ketone bodies up from the blood and reconvert them into acetyl-CoA, which can then be used as fuel in their citric acid cycles, as no other tissue can divert its oxaloacetate into the gluconeogenic pathway in the way that the liver does. Unlike free fatty acids, ketone bodies can cross the blood–brain barrier and are therefore available as fuel for the cells of the central nervous system, acting as a substitute for glucose, on which these cells normally survive.[17] The occurrence of high levels of ketone bodies in the blood during starvation, a low-carbohydrate diet, prolonged heavy exercise, and uncontrolled type-1 diabetes mellitus is known as ketosis, and in its extreme form in out-of-control type-1 diabetes mellitus, as ketoacidosis.
- On the other hand, when the cellular membranes.[17]
- In plants, de novo fatty acid synthesis occurs in the plastids. Many seeds accumulate large reservoirs of seed oils to support germination and early growth of the seedling before it is a net photosynthetic organism.
- The
- Acetyl-CoA can be malonation of proteins and other phytochemicals.[22] In plants, these include sesquiterpenes, brassinosteroids (hormones), and membrane sterols.
- Acetyl-CoA is produced by the breakdown of both
- Steroid synthesis:
- Acetyl-CoA participates in the mevalonate pathway by partaking in the synthesis of hydroxymethyl glutaryl-CoA.
- Acetylcholine synthesis:
- Acetyl-CoA is also an important component in the biogenic synthesis of the neurotransmitter acetylcholine. Choline, in combination with acetyl-CoA, is catalyzed by the enzyme choline acetyltransferase to produce acetylcholine and coenzyme A as a byproduct.
- Melatonin synthesis
- Acetylation
- Acetyl-CoA is also the source of the acetyl group incorporated onto certain
- Allosteric regulator
- Acetyl-CoA serves as an allosteric regulator of pyruvate dehydrogenase kinase (PDK). It regulates through the ratio of acetyl-CoA versus CoA. Increased concentration of acetyl-CoA activates PDK.[24]
- Acetyl-CoA is also an allosteric activator of pyruvate carboxylase.[25]
Interactive pathway map
Click on genes, proteins and metabolites below to visit
|
|
See also
References
- ^ ISBN 978-0-19-855299-4.
- ^ "Acetyl CoA Crossroads". chemistry.elmhurst.edu. Archived from the original on 2016-11-15. Retrieved 2016-11-08.
- ^ "Fatty Acids -- Structure of Acetyl CoA". library.med.utah.edu. Retrieved 2017-06-02.
- ^ "All Nobel Prizes in Physiology or Medicine". The Nobel Prize.
- PMID 31387584.
- ^ "5.12G: The Acetyl-CoA Pathway". 9 May 2017.
- ^ "Central Metabolic Intermediate". MedchemExpress.com. Retrieved 15 February 2024.
- PMID 20495057.
- S2CID 244613.
- ISBN 9780471675570.
- ^ "ACLY ATP citrate lyase [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2016-11-06.
- S2CID 16194968.
- ]
- ISBN 978-0716730514.
- ISBN 9781483183671.
- PMID 20195903.
- ^ ISBN 978-0-7167-2009-6.
- ^ "Oxidation of fatty acids". 2013-10-11.
- ^ "Ketone body metabolism". University of Waterloo.
- ^ PMID 17344645.
this process is outlined graphically in page 73
- ^ ISBN 978-0-471-21495-3.
- PMID 15608338.
- PMID 22089928.
- PMID 167775.
- PMID 18613815.
External links
- Acetyl+Coenzyme+A at the U.S. National Library of Medicine Medical Subject Headings (MeSH)