関: bisphosphate、diphosphoric acid、pyrophosphate

WordNet

a salt or ester of pyrophosphoric acid

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/11/03 13:19:23」(JST)

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In chemistry, the anion, the salts, and the esters 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. As well as the normal pyrophosphates, a number of hydrogen pyrophosphates also exist, such as Na₂H₂P₂O₇.

Chemistry[edit]

Pyrophosphates were originally prepared by heating phosphates (pyro from the Greek, meaning "fire"). Pyrophosphates generally exhibit the highest solubilities among the phosphates;^[1] moreover, they are good complexing agents for metal ions (such as calcium and many transition metals) and have many uses in industrial chemistry. Pyrophosphate is the first member of an entire series of polyphosphates.

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.

In biochemistry[edit]

Main article: Biochemistry

Pyrophosphates are very important in biochemistry. The anion P₂O₇⁴⁻ is abbreviated PP_i and is formed by the hydrolysis of ATP into AMP in cells.

ATP → AMP + PP_i

For example, when a nucleotide is incorporated into a growing DNA or RNA strand by a polymerase, pyrophosphate (PP_i) 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 hydrolyzes into inorganic phosphate:

P₂O₇⁴⁻ + H₂O → 2 HPO₄²⁻

or in biologists' shorthand notation:

PP_i + H₂O → 2 P_i

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.^[2]

(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 PP_i irreversible, and biochemical reactions coupled to this hydrolysis are irreversible as well.

PP_i 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).^[3] Cells may channel intracellular PP_i into ECF.^[4] ANK is a nonenzymatic plasma-membrane PP_i channel that supports extracellular PP_i levels.^[4] Defective function of the membrane PP_i channel ANK is associated with low extracellular PP_i and elevated intracellular PP_i.^[3] Ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) may function to raise extracellular PP_i.^[4]

From the standpoint of high energy phosphate accounting, the hydrolysis of ATP to AMP and PP_i requires two high-energy phosphates, as to reconstitute AMP into ATP requires two phosphorylation reactions.

AMP + ATP → 2 ADP

2 ADP + 2 P_i → 2 ATP

References[edit]

^ C.Michael Hogan. 2011. Phosphate. Encyclopedia of Earth. Topic ed. Andy Jorgensen. Ed.-in-Chief C.J.Cleveland. National Council for Science and the Environment. Washington DC
^ Huebner PWA, Milburn RM (May 1980). "Hydrolysis of pyrophosphate to orthophosphate promoted by cobalt(III). Evidence for the role of polynuclear species". Inorg Chem. 19 (5): 1267–72. doi:10.1021/ic50207a032.
^ ^a ^b Ho AM, Johnson MD, Kingsley DM (Jul 2000). "Role of the mouse ank gene in control of tissue calcification and arthritis". Science. 289 (5477): 265–70. doi:10.1126/science.289.5477.265. PMID 10894769.
^ ^a ^b ^c Rutsch F, Vaingankar S, Johnson K, Goldfine I, Maddux B, Schauerte P, Kalhoff H, Sano K, Boisvert WA, Superti-Furga A, Terkeltaub R (Feb 2001). "PC-1 nucleoside triphosphate pyrophosphohydrolase deficiency in idiopathic infantile arterial calcification". Am J Pathol. 158 (2): 543–54. doi:10.1016/S0002-9440(10)63996-X. PMC 1850320. PMID 11159191.

External links[edit]

Look up diphosphate or pyrophosphate in Wiktionary, the free dictionary.

Pyrophosphates at the US National Library of Medicine Medical Subject Headings (MeSH)

UpToDate Contents

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English Journal

Sonochemical precipitation of amorphous uranium phosphates from trialkyl phosphate solutions and their thermal conversion to UP2O7.

Doroshenko I1, Zurkova J2, Moravec Z2, Bezdicka P3, Pinkas J4.
Ultrasonics sonochemistry.Ultrason Sonochem.2015 Sep;26:157-62. doi: 10.1016/j.ultsonch.2015.01.016. Epub 2015 Jan 23.
Insoluble amorphous precipitates containing uranyl and phosphate ions are obtained by sonication of solutions of three uranyl precursors, UO2(X)2, X=NO3, CH3COO, CH3C(O)CHC(O)CH3 (acetylacetonate, acac), in triesters of phosphoric acid, OP(OR)3, R=Me (trimethyl phosphate, TMP), Et (triethyl phosphat
PMID 25640684

Evaluation of ionic liquids as alternative solvents for aldolase activity: Use of a new automated SIA methodology.

Cunha E1, Pinto PC2, Saraiva ML3.
Talanta.Talanta.2015 Aug 15;141:293-9. doi: 10.1016/j.talanta.2015.04.028. Epub 2015 Apr 16.
An automated methodology is proposed for the evaluation of a set of ionic liquids (ILs) as alternative reaction media for aldolase based synthetic processes. For that, the effect of traditionally used organic solvents and ILs on the activity of aldolase was studied by means of a novel automated meth
PMID 25966417

The kinetic characterization and X-ray structure of a putative benzoylformate decarboxylase from M. smegmatis highlights the difficulties in the functional annotation of ThDP-dependent enzymes.

Andrews FH1, Horton JD1, Shin D2, Yoon HJ1, Logsdon MG1, Malik AM1, Rogers MP1, Kneen MM1, Suh SW3, McLeish MJ4.
Biochimica et biophysica acta.Biochim Biophys Acta.2015 Aug;1854(8):1001-9. doi: 10.1016/j.bbapap.2015.04.027. Epub 2015 Apr 30.
Benzoylformate decarboxylase (BFDC) is a thiamin diphosphate (ThDP)-dependent enzyme that catalyzes the nonoxidative decarboxylation of benzoylformate. It is the penultimate enzyme in both the mandelate pathway and the d-phenylglycine degradation pathway. The ThDP-dependent Enzyme Engineering Databa
PMID 25936776

Japanese Journal

古細菌イソプレノイド生合成に関わるタイプ2イソペンテニル二リン酸イソメラーゼにおけるフラビン補酵素の特異な機能

邊見久
ビタミン 85(1), 1-8, 2011-01-25
… Type 2 isopentenyl diphosphate isomerase is a flavoenzyme that catalyzes interconversion between isopentenyl diphosphate and dimethylallyl diphosphate, which are precursors for the biosynthesis of diverse isoprenoid compounds. … From our studies using type 2 isopentenyl diphosphate isomerase from a thermoacidophilic archaeon Sulfolobus shibatae, consumption of only a catalytic amount of NAD(P)H and actual requirement for reduced FMN as a coenzyme were shown. …
NAID 110008440790

ユニークなフラビン酵素--タイプ2イソペンテニル二リン酸イソメラーゼ

邊見久
生化学 83(4), 304-307, 2011-04
NAID 40018837340

Related Pictures

★リンクテーブル★

リンク元	「二リン酸」「二リン酸エステル」「pyrophosphate」「bisphosphate」「二リン酸塩」
拡張検索	「ribonucleoside diphosphate reductase」「nucleoside diphosphate sugar」「adenosine diphosphate sugar」「guanosine diphosphate sugar」

「二リン酸」

Pyrophosphate
	Other names Diphosphate
Identifiers
PubChem	644102
ChemSpider	559142
DrugBank	DB04160
ChEBI	CHEBI:18361
Jmol-3D images	Image 1
	SMILES [O-]P(=O)([O-])OP(=O)([O-])[O-] ;
	InChI InChI=1S/H4O7P2/c1-8(2,3)7-9(4,5)6/h(H2,1,2,3)(H2,4,5,6)/p-4 ; Key: XPPKVPWEQAFLFU-UHFFFAOYSA-J InChI=1/H4O7P2/c1-8(2,3)7-9(4,5)6/h(H2,1,2,3)(H2,4,5,6)/p-4; Key: XPPKVPWEQAFLFU-XBHQNQODAI ;
Properties
Molecular formula	P2O74−
	(verify) (what is: /?); Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
	Infobox references