View source for Phosphocreatine

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| ImageFile1 = Fosfocreatine Wiki str.png
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| IUPACName = 2-[Methyl-(N'-phosphonocarbamimidoyl)<br>amino]acetic acid
| OtherNames = Creatine phosphate<br>Phosphorylcreatine<br>Creatine-P
| Section1 = {{Chembox Identifiers
| Abbreviations = PCr
| CASNo = 67-07-2
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| PubChem = 587
| SMILES = OC(CN(C)C(N)=NP(O)(O)=O)=O
| InChI = 1/C4H10N3O5P/c1-7(2-3(8)9)<br>4(5)6-13(10,11)12/h2H2,1H3,(H,8,9)<br>(H4,5,6,10,11,12)/f/h8,10-11H,5H2/b6-4+
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| Section2 = {{Chembox Properties
| Formula = C<sub>4</sub>H<sub>10</sub>N<sub>3</sub>O<sub>5</sub>P
| MolarMass = 211.113 g/mol
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== Overview ==
'''Phosphocreatine''', also known as '''creatine phosphate''' (CP) or '''PCr''' ('''Pcr'''), is a [[phosphorylation|phosphorylated]] [[creatine]] molecule that serves as a rapidly mobilizable reserve of high-energy phosphates in skeletal [[muscle]] and the [[brain]].

==Chemistry==
Phosphocreatine is formed from parts of three amino acids: [[arginine]] (Arg), [[glycine]] (Gly), and [[methionine]] (Met). It can be synthesized by formation of [[guanidinoacetate]] from Arg and Gly (in [[kidney]]) followed by [[methylation]] ([[S-adenosyl methionine]] is required) to creatine (in [[liver]]), and [[phosphorylation]] by [[creatine kinase]] ([[Adenosine triphosphate|ATP]] is required) to phosphocreatine (in muscle); catabolism: dehydration to form the cyclic [[Schiff base]] [[creatinine]]. Phosphocreatine is synthesized in the [[liver]] and transported to the muscle cells, via the bloodstream, for storage.

The [[creatine phosphate shuttle]] facilitates transport of high energy phosphate from [[mitochondria]].

==Function==
Phosphocreatine can anaerobically donate a phosphate group to [[Adenosine diphosphate|ADP]] to form [[Adenosine triphosphate|ATP]] during the first 2 to 7 seconds following an intense muscular or neuronal effort. Conversely, excess [[Adenosine triphosphate|ATP]] can be used during a period of low effort to convert [[creatine]] to phosphocreatine. The reversible phosphorylation of creatine (i.e., both the forward and backward reaction) is catalyzed by several [[creatine kinase]]s. The presence of creatine kinase ([[CK-MB]], MB for muscle/brain) in [[blood plasma]] is indicative of tissue damage and is used in the diagnosis of myocardial infarction.<ref>{{cite journal
| author = Schlattner, U.; Tokarska-Schlattner, M., and Wallimann, T.
| title = Mitochondrial creatine kinase in human health and disease
| year = 2006
| journal = Biochimica et Biophysica Acta - Molecular Basis of Disease
| volume = 1762
| pmid = 16236486
| issue = 2
| pages = 164–180
| doi = 10.1016/j.bbadis.2005.09.004
}}</ref> The cell's ability to generate phosphocreatine from excess [[Adenosine triphosphate|ATP]] during rest, as well as its use of phosphocreatine for quick regeneration of [[Adenosine triphosphate|ATP]] during intense activity, provides a spatial and temporal buffer of [[Adenosine triphosphate|ATP]] concentration. In other words, phosphocreatine acts as high-energy reserve in a coupled reaction; the energy given off from donating the phosphate group is used to regenerate the other compound - in this case, [[Adenosine triphosphate|ATP]]. Phosphocreatine plays a particularly important role in tissues that have high, fluctuating energy demands such as muscle and brain.

== History ==
The discovery of phosphocreatine<ref>{{cite book
| author = Saks, Valdur
| year = 2007
| title = Molecular system bioenergetics: energy for life
| place = Weinheim
| publisher = Wiley-VCH
| page = 2
| isbn = 978-3-527-31787-5
}}</ref><ref name=ochoa>{{Cite book
| last = Ochoa
| first = Severo
| author-link =
| year = 1989
| date =
| publication-date =
| contribution =
| contribution-url =
| editor-last = Sherman
| editor-first = E. J.
| editor-link =
| editor2-last =National Academy of Sciences
| editor2-first =
| editor2-link =
| title = David Nachmansohn
| edition =
| series = Biographical Memoirs
| place =
| publication-place =
| publisher = National Academies Press
| volume = 58
| pages = 357–404
| isbn = 978-0-309-03938-3
| url =
}}</ref> was reported by Grace and Philip Eggleton of the [[University of Cambridge]]<ref>{{cite journal 
| first1 = Philip 
| last1 = Eggleton
| first2 = Grace Palmer
| last2 = Eggleton
| title = The inorganic phosphate and a labile form of organic phosphate in the gastrocnemius of the frog
| year = 1927
| journal = Biochemical Journal
| volume = 21
| issue = 1
| pages = 190–195
| url = http://www.biochemj.org/bj/021/bj0210190.htm 
| pmid = 16743804 
| pmc = 1251888}}</ref> and separately by [[Cyrus Fiske]] and [[Yellapragada Subbarow]] of the [[Harvard Medical School]]<ref>{{cite journal 
| last1 = Fiske
| first1 = Cyrus H.
| last2 = Subbarao
| first2 = Yellapragada
| title = The nature of the 'inorganic phosphate' in voluntary muscle
| year = 1927
| journal = Science
| volume = 65
| issue = 1686
| pages = 401–403
| url = http://www.sciencemag.org/content/vol65/issue1686/index.dtl#articles 
| doi = 10.1126/science.65.1686.401 
| pmid = 17807679}}</ref>  in 1927. A few years later [[David Nachmansohn]], working under [[Otto Fritz Meyerhof|Meyerhof]] at the [[Kaiser Wilhelm Institute]] in Dahlem, Berlin, contributed to the understanding of the phosphocreatine's role in the cell.<ref name=ochoa/>

== References ==
{{Reflist|2}}

==External links==
* [http://www.hmdb.ca/metabolites/HMDB01511 Human Metabolome Database] at the [[University of Alberta]]

[[Category:drug]]
[[Category:Biomolecules]]
[[Category:Guanidines]]
[[Category:Phosphoramidates]]