Pyrophosphate
Encyclopedia
In chemistry
, the anion, the salt
s, and the ester
s of pyrophosphoric acid
are called pyrophosphates. Any salt or ester containing two phosphate groups is called a diphosphate. As a food additive
, diphosphates are known as E450.
s.
The term pyrophosphate is also the name of esters formed by the condensation
of a phosphorylated biological compound with inorganic phosphate as for dimethylallyl pyrophosphate
. This bond is also referred to as a high-energy phosphate bond.
The synthesis of tetraethyl pyrophosphate
was first described in 1854 by Philip de Clermount at a meeting of the French Academy of Sciences.
of ATP
into AMP
in cells
.
For example, when a nucleotide is incorporated into a growing DNA
or RNA
strand by a polymerase
, pyrophosphate (PPi) is released. Pyrophosphorolysis is the reverse of the polymerization
reaction in which pyrophosphate reacts with the 3'-nucleotidemonophosphate (NMP
or dNMP), which is removed from the oligonucleotide
to release the corresponding triphosphate (dNTP from DNA, or NTP from RNA).
The pyrophosphate anion has the structure P2O74−, and is an acid anhydride of phosphate
. It is unstable in aqueous solution
and hydrolyze
s into inorganic phosphate:
or in biologists' shorthand notation:
In the absence of enzymic catalysis, hydrolysis reactions of simple polyphosphates such as pyrophosphate, linear triphosphate, ADP
, and ATP normally proceed extremely slowly in all but highly acidic media.
(The reverse of this reaction is a method of preparing pyrophosphates by heating phosphates.)
This hydrolysis to inorganic phosphate effectively renders the cleavage of ATP to AMP and PPi irreversible
, and biochemical reactions coupled to this hydrolysis are irreversible as well.
PPi occurs in synovial fluid
, blood plasma
, and urine
at levels sufficient to block calcification
and may be a natural inhibitor of hydroxyapatite formation in extracellular fluid
(ECF). Cells may channel intracellular PPi into ECF. ANK
is a nonenzymatic plasma-membrane PPi channel that supports extracellular PPi levels. Defective function of the membrane PPi channel ANK is associated with low extracellular PPi and elevated intracellular PPi. Ectonucleotide pyrophosphatase/phosphodiesterase
(ENPP) may function to raise extracellular PPi.
From the standpoint of high energy phosphate
accounting, the hydrolysis of ATP to AMP and PPi requires two high-energy phosphates, as to reconstitute AMP into ATP requires two phosphorylation
reactions.
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
, the anion, the salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
s, and the ester
Ester
Esters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s of pyrophosphoric acid
Pyrophosphoric acid
Pyrophosphoric acid, also known under the name diphosphoric acid, is colorless, odorless, hygroscopic and is soluble in water, diethyl ether, and ethyl alcohol. It is produced from phosphoric acid by dehydration. Pyrophosphoric acid slowly hydrolyzes in the presence of water into phosphoric...
are called pyrophosphates. Any salt or ester containing two phosphate groups is called a diphosphate. As a food additive
Food additive
Food additives are substances added to food to preserve flavor or enhance its taste and appearance.Some additives have been used for centuries; for example, preserving food by pickling , salting, as with bacon, preserving sweets or using sulfur dioxide as in some wines...
, diphosphates are known as E450.
Chemistry
Pyrophosphates were originally prepared by heating phosphates (pyro- from the Greek, meaning fire). Pyrophosphates are good complexing agents and have many uses in industrial chemistry. Pyrophosphate is the first member of an entire series of polyphosphatePolyphosphate
Triphosphates are salts or esters of polymeric oxyanions formed from tetrahedral PO4 structural units linked together by sharing oxygen atoms. When two corners are shared the polyphosphate may have a linear chain structure or a cyclic ring structure. In biology the polyphosphate esters AMP, ADP...
s.
The term pyrophosphate is also the name of esters formed by the condensation
Condensation reaction
A condensation reaction is a chemical reaction in which two molecules or moieties combine to form one single molecule, together with the loss of a small molecule. When this small molecule is water, it is known as a dehydration reaction; other possible small molecules lost are hydrogen chloride,...
of a phosphorylated biological compound with inorganic phosphate as for dimethylallyl pyrophosphate
Dimethylallyl pyrophosphate
Dimethylallyl pyrophosphate is an intermediate product of both mevalonic acid pathway and DOXP/MEP pathway. It is an isomer of isopentenyl pyrophosphate and exists in virtually all life forms...
. This bond is also referred to as a high-energy phosphate bond.
The synthesis of tetraethyl pyrophosphate
Tetraethyl pyrophosphate
Tetraethyl pyrophosphate, abbreviated TEPP, is an organophosphate compound. It is used as a pesticide.This compound is a clear, colorless liquid. It is soluble in water, but hydrolyzes rapidly. It was first synthesized by Philippe de Clermont...
was first described in 1854 by Philip de Clermount at a meeting of the French Academy of Sciences.
In biochemistry
Pyrophosphates are very important in biochemistry. The anion P2O74− is abbreviated PPi and is formed by the hydrolysisHydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
of ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
into AMP
Adenosine monophosphate
Adenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...
in cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....
.
- ATP → AMPAdenosine monophosphateAdenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...
+ PPi
For example, when a nucleotide is incorporated into a growing DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
or RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
strand by a polymerase
Polymerase
A polymerase is an enzyme whose central function is associated with polymers of nucleic acids such as RNA and DNA.The primary function of a polymerase is the polymerization of new DNA or RNA against an existing DNA or RNA template in the processes of replication and transcription...
, pyrophosphate (PPi) is released. Pyrophosphorolysis is the reverse of the polymerization
Polymerization
In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains...
reaction in which pyrophosphate reacts with the 3'-nucleotidemonophosphate (NMP
NMP
NMP can be:*NMP , a visual art collective from the Republic of Macedonia*NMP , is a common abbreviation used as a response to email or memo messages, to flag that the previous message has been ignored....
or dNMP), which is removed from the oligonucleotide
Oligonucleotide
An oligonucleotide is a short nucleic acid polymer, typically with fifty or fewer bases. Although they can be formed by bond cleavage of longer segments, they are now more commonly synthesized, in a sequence-specific manner, from individual nucleoside phosphoramidites...
to release the corresponding triphosphate (dNTP from DNA, or NTP from RNA).
The pyrophosphate anion has the structure P2O74−, and is an acid anhydride of phosphate
Phosphate
A phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
. It is unstable in aqueous solution
Aqueous solution
An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...
and hydrolyze
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
s into inorganic phosphate:
- P2O74− + H2O → 2 HPO42−
or in biologists' shorthand notation:
- PPi + H2O → 2 Pi
In the absence of enzymic catalysis, hydrolysis reactions of simple polyphosphates such as pyrophosphate, linear triphosphate, ADP
Adenosine diphosphate
Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
, and ATP normally proceed extremely slowly in all but highly acidic media.
(The reverse of this reaction is a method of preparing pyrophosphates by heating phosphates.)
This hydrolysis to inorganic phosphate effectively renders the cleavage of ATP to AMP and PPi irreversible
Hydrolysis
Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...
, and biochemical reactions coupled to this hydrolysis are irreversible as well.
PPi occurs in synovial fluid
Synovial fluid
Synovial fluid is a viscous, non-Newtonian fluid found in the cavities of synovial joints. With its yolk-like consistency , the principal role of synovial fluid is to reduce friction between the articular cartilage of synovial joints during movement.-Overview:The inner membrane of synovial joints...
, blood plasma
Blood plasma
Blood plasma is the straw-colored liquid component of blood in which the blood cells in whole blood are normally suspended. It makes up about 55% of the total blood volume. It is the intravascular fluid part of extracellular fluid...
, and urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...
at levels sufficient to block calcification
Calcification
Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...
and may be a natural inhibitor of hydroxyapatite formation in extracellular fluid
Extracellular fluid
Extracellular fluid usually denotes all body fluid outside of cells. The remainder is called intracellular fluid.In some animals, including mammals, the extracellular fluid can be divided into two major subcompartments, interstitial fluid and blood plasma...
(ECF). Cells may channel intracellular PPi into ECF. ANK
ANKH
Progressive ankylosis protein homolog is a protein that in humans is encoded by the ANKH gene.-External links:*-Further reading:...
is a nonenzymatic plasma-membrane PPi channel that supports extracellular PPi levels. Defective function of the membrane PPi channel ANK is associated with low extracellular PPi and elevated intracellular PPi. Ectonucleotide pyrophosphatase/phosphodiesterase
Ectonucleotide pyrophosphatase/phosphodiesterase 1
Ectonucleotide pyrophosphatase/phosphodiesterase family member 1 is an enzyme that in humans is encoded by the ENPP1 gene.-Interactions:Ectonucleotide pyrophosphatase/phosphodiesterase 1 has been shown to interact with Insulin receptor....
(ENPP) may function to raise extracellular PPi.
From the standpoint of high energy phosphate
High energy phosphate
High-energy phosphate can mean one of two things:* The phosphate-phosphate bonds formed when compounds such as adenosine diphosphate and adenosine triphosphate are created....
accounting, the hydrolysis of ATP to AMP and PPi requires two high-energy phosphates, as to reconstitute AMP into ATP requires two phosphorylation
Phosphorylation
Phosphorylation is the addition of a phosphate group to a protein or other organic molecule. Phosphorylation activates or deactivates many protein enzymes....
reactions.
- AMP + ATP → 2 ADPAdenosine diphosphateAdenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
- 2 ADP + 2 Pi → 2 ATP
See also
- Adenosine monophosphateAdenosine monophosphateAdenosine monophosphate , also known as 5'-adenylic acid, is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid and the nucleoside adenosine. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine...
- Adenosine diphosphateAdenosine diphosphateAdenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
- Adenosine triphosphateAdenosine triphosphateAdenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
- ATPaseATPaseATPases are a class of enzymes that catalyze the decomposition of adenosine triphosphate into adenosine diphosphate and a free phosphate ion. This dephosphorylation reaction releases energy, which the enzyme harnesses to drive other chemical reactions that would not otherwise occur...
- ATP hydrolysisATP hydrolysisATP hydrolysis is the reaction by which chemical energy that has been stored and transported in the high-energy phosphoanhydridic bonds in ATP is released, for example in the muscles, to produce work. The product is ADP and an inorganic phosphate, orthophosphate...
- ATP synthaseATP synthaseright|thumb|300px|Molecular model of ATP synthase by X-ray diffraction methodATP synthase is an important enzyme that provides energy for the cell to use through the synthesis of adenosine triphosphate . ATP is the most commonly used "energy currency" of cells from most organisms...
- BiochemistryBiochemistryBiochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...
- BoneBoneBones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
- Calcium pyrophosphateCalcium pyrophosphateCalcium pyrophosphate is a chemical compound that can be formed by the reaction of pyrophosphoric acid and a calcium base or by strongly heating calcium phosphate or calcium ammonium phosphate....
- Calcium pyrophosphate dihydrate deposition disease
- CatalysisCatalysisCatalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
- DNADNADeoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
- High energy phosphateHigh energy phosphateHigh-energy phosphate can mean one of two things:* The phosphate-phosphate bonds formed when compounds such as adenosine diphosphate and adenosine triphosphate are created....
- Inorganic pyrophosphataseInorganic pyrophosphatasePyrophosphatase is an enzyme that catalyzes the conversion of one molecule of pyrophosphate to two phosphate ions. This is a highly exergonic reaction, and therefore can be coupled to unfavorable biochemical transformations in order to drive these transformations to completion...
- List of biochemical phosphate reactions
- List of human ATPase genes
- Nucleoside triphosphateNucleoside triphosphateNucleoside triphosphate is a nucleoside with three phosphates. Natural nucleoside triphosphates include adenosine triphosphate , guanosine triphosphate , cytidine triphosphate , 5-methyluridine triphosphate , and uridine triphosphate . These terms refer to those nucleoside triphosphates that...
- NucleotideNucleotideNucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
- OrganophosphateOrganophosphateAn organophosphate is the general name for esters of phosphoric acid. Phosphates are probably the most pervasive organophosphorus compounds. Many of the most important biochemicals are organophosphates, including DNA and RNA as well as many cofactors that are essential for life...
- Oxidative phosphorylationOxidative phosphorylationOxidative phosphorylation is a metabolic pathway that uses energy released by the oxidation of nutrients to produce adenosine triphosphate . Although the many forms of life on earth use a range of different nutrients, almost all aerobic organisms carry out oxidative phosphorylation to produce ATP,...
- PhosphatePhosphateA phosphate, an inorganic chemical, is a salt of phosphoric acid. In organic chemistry, a phosphate, or organophosphate, is an ester of phosphoric acid. Organic phosphates are important in biochemistry and biogeochemistry or ecology. Inorganic phosphates are mined to obtain phosphorus for use in...
- Phosphate homeostasis
- Phosphate reaction
- Phosphoric acidPhosphoric acidPhosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...
- Phosphoric acids and phosphatesPhosphoric acids and PhosphatesThere are various kinds of phosphoric acids and phosphates. Of the many phosphorus oxoacids, the phosphoric acids constitute the largest and most diverse group. The simplest phosphoric acid series begins with monophosphoric acid, continues with many oligophosphoric acids such as diphosphoric acid...
- Ribonucleoside monophosphate
- RNARNARibonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
- Sodium pyrophosphateSodium pyrophosphateTetrasodium pyrophosphate, also called sodium pyrophosphate, tetrasodium phosphate or TSPP, is a colorless transparent crystalline chemical compound with the formula Na4P2O7. It contains the pyrophosphate ion and sodium cation. Toxicity is approximately twice that of table salt when ingested...
- Structural phosphate
- Superphosphate
- Thiamine pyrophosphateThiamine pyrophosphateThiamine pyrophosphate , or thiamine diphosphate , is a thiamine derivative which is produced by the enzyme thiamine pyrophosphatase. Thiamine pyrophosphate is a coenzyme that is present in all living systems, in which it catalyzes several biochemical reactions...
- ToothToothTeeth are small, calcified, whitish structures found in the jaws of many vertebrates that are used to break down food. Some animals, particularly carnivores, also use teeth for hunting or for defensive purposes. The roots of teeth are embedded in the Mandible bone or the Maxillary bone and are...
- Zinc pyrophosphateZinc pyrophosphateZinc pyrophospate is an inorganic chemical compound. It is useful in gravimetric analysis of zinc. Zinc pyrophosphate is obtained by precipitating zinc as a phosphate, then heating over 1123 K....