Adenosine monophosphate
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (February 2013) |
Names | |
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IUPAC name
5′-Adenylic acid
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Systematic IUPAC name
[(2R,3S,4R,5R)-5-(6-Amino-9H-purin-9-yl)-3,4-dihydroxyoxolan-2-yl]methyl dihydrogen phosphate | |
Other names
Adenosine 5'-monophosphate
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Identifiers | |
3D model (
JSmol ) |
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ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard
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100.000.455 |
IUPHAR/BPS |
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KEGG | |
MeSH | Adenosine+monophosphate |
PubChem CID
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UNII | |
CompTox Dashboard (EPA)
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Properties | |
C10H14N5O7P | |
Molar mass | 347.22 g/mol |
Appearance | white crystalline powder |
Density | 2.32 g/mL |
Melting point | 178 to 185 °C (352 to 365 °F; 451 to 458 K) |
Boiling point | 798.5 °C (1,469.3 °F; 1,071.7 K) |
Acidity (pKa) | 0.9[citation needed], 3.8, 6.1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Adenosine monophosphate (AMP), also known as 5'-adenylic acid, is a nucleotide. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine. It is an ester of phosphoric acid and the nucleoside adenosine.[1] As a substituent it takes the form of the prefix adenylyl-.[2]
AMP plays an important role in many cellular metabolic processes, being interconverted to adenosine triphosphate (ATP) and adenosine diphosphate (ADP), as well as allosterically activating enzymes such as myophosphorylase-b. AMP is also a component in the synthesis of RNA.[3] AMP is present in all known forms of life.[4]
Production and degradation
AMP does not have the high energy
- 2 ADP → ATP + AMP
Or AMP may be produced by the
- ADP + H2O → AMP + Pi
AMP can also be formed by hydrolysis of ATP into AMP and pyrophosphate:
- ATP + H2O → AMP + PPi
When RNA is broken down by living systems, nucleoside monophosphates, including adenosine monophosphate, are formed.
AMP can be regenerated to ATP as follows:
- AMP + ATP → 2 ADP (adenylate kinase in the opposite direction)
- ADP + Pi → ATP (this step is most often performed in aerobes by the ATP synthase during oxidative phosphorylation)
AMP can be converted into
In a catabolic pathway, the purine nucleotide cycle, adenosine monophosphate can be converted to uric acid, which is excreted from the body in mammals.[7]
Physiological role in regulation
AMP-activated kinase regulation
The eukaryotic cell enzyme 5' adenosine monophosphate-activated protein kinase, or AMPK, utilizes AMP for homeostatic energy processes during times of high cellular energy expenditure, such as exercise.[8] Since ATP cleavage, and corresponding phosphorylation reactions, are utilized in various processes throughout the body as a source of energy, ATP production is necessary to further create energy for those mammalian cells. AMPK, as a cellular energy sensor, is activated by decreasing levels of ATP, which is naturally accompanied by increasing levels of ADP and AMP.[9]
Though phosphorylation appears to be the main activator for AMPK, some studies suggest that AMP is an allosteric regulator as well as a direct agonist for AMPK.[10] Furthermore, other studies suggest that the high ratio of AMP:ATP levels in cells, rather than just AMP, activate AMPK.[11] For example, the AMP-activated kinases of Caenorhabditis elegans and Drosophila melanogaster were found to have been activated by AMP, while yeast and plant kinases were not allosterically activated by AMP.[11]
AMP binds to the γ-subunit of AMPK, leading to the activation of the kinase, and then eventually a cascade of other processes such as the activation of catabolic pathways and inhibition of anabolic pathways to regenerate ATP. Catabolic mechanisms, which generate ATP through the release of energy from breaking down molecules, are activated by the AMPK enzyme while anabolic mechanisms, which utilize energy from ATP to form products, are inhibited.[12] Though the γ-subunit can bind AMP/ADP/ATP, only the binding of AMP/ADP results in a conformational shift of the enzyme protein. This variance in AMP/ADP versus ATP binding leads to a shift in the dephosphorylation state for the enzyme.[13] The dephosphorylation of AMPK through various protein phosphatases completely inactivates catalytic function. AMP/ADP protects AMPK from being inactivated by binding to the γ-subunit and maintaining the dephosphorylation state.[14]
cAMP
AMP can also exist as a cyclic structure known as
See also
References
- ^ "Adenosine monophosphate (Compound)". PubChem. NCBI. Retrieved 30 April 2020.
- .
- PMID 26435376.
- ^ "Adenosine monophosphate". The Human Metabolome Database. Retrieved 3 July 2020.
- PMID 21188163.
- ISBN 978-0-12-370491-7, retrieved 10 October 2023
- PMID 26316329.
- PMID 19196246.
- PMID 21769098.
- PMID 24486219.
- ^ PMID 21937710.
- PMID 21067629.
- PMID 25422142.
- PMID 21399626.
- PMID 26721678.
- ISBN 1-59377-192-4.
- ^ "15.3: Glycogenolyis and its Regulation by Glucagon and Epinephrine Signaling". Biology LibreTexts. 1 January 2022. Retrieved 10 October 2023.
Further reading
- Ming D, Ninomiya Y, Margolskee RF (August 1999). "Blocking taste receptor activation of gustducin inhibits gustatory responses to bitter compounds". Proceedings of the National Academy of Sciences of the United States of America. 96 (17): 9903–8. PMID 10449792.