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| Names | |
|---|---|
| Preferred IUPAC name 2-(Phosphonooxy)prop-2-enoic acid | |
| Other names Phosphoenolpyruvic acid, PEP | |
| Identifiers | |
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3D model (JSmol) | |
| ChEBI | |
| ChemSpider |
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| DrugBank |
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| ECHA InfoCard | 100.004.830 |
| KEGG |
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| UNII | |
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| Properties | |
| C3H5O6P | |
| Molar mass | 168.042 |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Phosphoenolpyruvate (2-phosphoenolpyruvate,PEP) is thecarboxylic acid derived from theenol ofpyruvate and aphosphateanion. It exists as ananion. PEP is an important intermediate inbiochemistry. It has thehighest-energy phosphate bond found (−61.9 kJ/mol) in organisms, and is involved inglycolysis andgluconeogenesis. In plants, it is also involved in the biosynthesis of variousaromatic compounds, and incarbon fixation; in bacteria, it is also used as the source of energy for thephosphotransferase system.[1][2]
PEP is formed by the action of theenzymeenolase on2-phosphoglyceric acid. Metabolism of PEP topyruvic acid bypyruvate kinase (PK) generatesadenosine triphosphate (ATP) viasubstrate-level phosphorylation. ATP is one of the major currencies of chemical energy withincells.[citation needed]
| 2-phospho-D-glycerate | Enolase | phosphoenolpyruvate | Pyruvate kinase | pyruvate | ||
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| H2O | ADP | ATP | ||||
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| H2O | ||||||
CompoundC00631 atKEGG Pathway Database.Enzyme4.2.1.11 atKEGG Pathway Database.CompoundC00074 atKEGG Pathway Database.Enzyme2.7.1.40 atKEGG Pathway Database.CompoundC00022 atKEGG Pathway Database.
PEP is formed from thedecarboxylation ofoxaloacetate andhydrolysis of oneguanosine triphosphate molecule. This reaction iscatalyzed by the enzymephosphoenolpyruvate carboxykinase (PEPCK). This reaction is arate-limiting step in gluconeogenesis:[3]
Click on genes, proteins and metabolites below to link to respective articles.[§ 1]
PEP may be used for the synthesis ofchorismate through theshikimate pathway.[4] Chorismate may then be metabolized into the aromaticamino acids (phenylalanine,tryptophan andtyrosine) and other aromatic compounds. The first step is when Phosphoenolpyruvate anderythrose-4-phosphate react to form3-deoxy-D-arabinoheptulosonate-7-phosphate (DAHP), in a reaction catalyzed by the enzymeDAHP synthase.
In addition, inC4 plants, PEP serves as an importantsubstrate incarbon fixation. The chemical equation, as catalyzed byphosphoenolpyruvate carboxylase (PEP carboxylase), is:
