Phosphoenolpyruvate

Phosphoenolpyruvate

Chembox new
ImageFile=Phosphoenolpyruvic acid.svg
ImageSize=
IUPACName=2-phosphonooxyprop-2-enoic acid
OtherNames=Phosphoenolpyruvic acid, PEP
Section1= Chembox Identifiers
CASNo=138-08-9
PubChem=1005
ChemSpiderID = 980
SMILES=C=C(C(=O)O)OP(=O)(O)O

Section2= Chembox Properties
Formula=C3H5O6P
MolarMass=168.042
Appearance=
Density=
MeltingPt=
BoilingPt=
Solubility=

Section3= Chembox Hazards
MainHazards=
FlashPt=
Autoignition=

Phosphoenolpyruvate (synonyms: phosphoenolpyruvic acid, PEP) is an important chemical compound in biochemistry. It has the high-energy phosphate bond found (-61.9 KJ/mol) in living organisms, and is involved in glycolysis and gluconeogenesis. In plants, it is also involved in the biosynthesis of various aromatic compounds, and in carbon fixation.

In glycolysis

PEP is formed by the action of the enzyme enolase on 2-phosphoglycerate. Metabolism of PEP to pyruvate by pyruvate kinase (PK) generates 1 molecule of adenosine triphosphate (ATP) via substrate-level phosphorylation. ATP is one of the major currencies of chemical energy within cells.

Biochemical Reaction
reaction_A_major_substrate=2-phospho-D-glycerate
reaction_A_major_substrate_

reaction_A_foward_enzyme=Enolase
reaction_A_reverse_enzyme=Enolase
reaction_A_reaction_direction_(forward/reversible/reverse)=reversible
reaction_A_minor_reverse_product(s)=
reaction_A_minor_reverse_substrate(s)=H2O
reaction_A_minor_foward_substrate(s)=
reaction_A_minor_foward_product(s)=H2O
reaction_A_major_product=phosphoenolpyruvate
reaction_A_major_product_

reaction_B_foward_enzyme=Pyruvate kinase
reaction_B_reverse_enzyme=Pyruvate kinase
reaction_B_reaction_direction_(foward/reversible/reverse)=reversible
reaction_B_minor_foward_substrate(s)=ADP
reaction_B_minor_foward_product(s)=ATP
reaction_B_minor_reverse_product(s)=
reaction_B_minor_reverse_substrate(s)=
reaction_B_major_product=pyruvate
reaction_B_major_product_

In gluconeogenesis

PEP is formed from the decarboxylation of oxaloacetate and hydrolysis of one guanosine triphosphate molecule. This reaction is catalyzed by the enzyme phosphoenolpyruvate carboxykinase (PEPCK). This reaction is a rate-limiting step in gluconeogenesis: [cite web |url=http://www.ebi.ac.uk/interpro/IEntry?ac=IPR008209 |title=InterPro: IPR008209 Phosphoenolpyruvate carboxykinase, GTP-utilising |accessdate=2007-08-17 |format= |work=]

:GTP + oxaloacetate → GDP + phosphoenolpyruvate + CO2

In plants

PEP may be used for the synthesis of chorismate through the shikimate pathway. [cite web |url=http://www.biocarta.com/pathfiles/chorismatePathway.asp |title=BioCarta - Charting Pathways of Life |accessdate=2007-08-17 |format= |work=] Chorismate may then be metabolized into the aromatic amino acids (phenylalanine, tryptophan and tyrosine) and other aromatic compounds.

In addition, in C₄ plants, PEP serves as an important substrate in carbon fixation. The chemical equation, as catalyzed by phosphoenolpyruvate carboxylase (PEP carboxylase), is:

:PEP + CO2 → oxaloacetate

References


Wikimedia Foundation. 2010.

Игры ⚽ Поможем решить контрольную работу

Look at other dictionaries:

  • Phosphoenolpyruvate carboxylase — Identifiers EC number 4.1.1.31 CAS number 9067 77 0 …   Wikipedia

  • Phosphoénolpyruvate carboxylase — ] PEPC d’E. coli. PDB 1FIY …   Wikipédia en Français

  • Phosphoenolpyruvate carboxykinase — Not to be confused with Phosphoenolpyruvate carboxylase. Phosphoenolpyruvate carboxykinase PDB rendering based on 1khb. Identifiers Symbol …   Wikipedia

  • Phosphoenolpyruvate mutase — In enzymology, a phosphoenolpyruvate mutase (EC number|5.4.2.9) is an enzyme that catalyzes the chemical reaction:phosphoenolpyruvate ightleftharpoons 3 phosphonopyruvateHence, this enzyme has one substrate, phosphoenolpyruvate, and one product,… …   Wikipedia

  • Phosphoenolpyruvate-protein phosphotransferase — In enzymology, a phosphoenolpyruvate protein phosphotransferase (EC number|2.7.3.9) is an enzyme that catalyzes the chemical reaction:phosphoenolpyruvate + protein histidine ightleftharpoons pyruvate + protein Npi phospho L histidineThus, the two …   Wikipedia

  • Phosphoenolpyruvate phosphatase — In enzymology, a phosphoenolpyruvate phosphatase (EC number|3.1.3.60) is an enzyme that catalyzes the chemical reaction:phosphoenolpyruvate + H2O ightleftharpoons pyruvate + phosphateThus, the two substrates of this enzyme are phosphoenolpyruvate …   Wikipedia

  • Phosphoenolpyruvate-glycerone phosphotransferase — In enzymology, a phosphoenolpyruvate glycerone phosphotransferase (EC number|2.7.1.121) is an enzyme that catalyzes the chemical reaction:phosphoenolpyruvate + glycerone ightleftharpoons pyruvate + glycerone phosphateThus, the two substrates of… …   Wikipedia

  • phosphoenolpyruvate carboxykinase (GTP) — phos·pho·enol·py·ru·vate car·boxy·ki·nase (GTP) (fos″fo e″nol piґroo vāt kahr bok″se kiґnās) [EC 4.1.1.32] an enzyme of the lyase class that catalyzes the decarboxylation and phosphorylation of oxaloacetate to form… …   Medical dictionary

  • phosphoenolpyruvate — noun Date: 1956 a salt or ester of phosphoenolpyruvic acid …   New Collegiate Dictionary

  • Phosphoenolpyruvate — Phosphoénol pyruvate Pour les articles homonymes, voir PEP. Phosphoénol pyruvate …   Wikipédia en Français

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”