phosphocreatine

Phosphocreatine
IUPAC name	N-Methyl-N-(phosphonocarbamimidoyl)glycine
Other names	creatine phosphate phosphorylcreatine creatine-P phosphagen
Identifiers
Abbreviations	PCr
CAS number	67-07-2 Y
PubChem	587
EC number	200-643-9
SMILES	OC(CN(C)C(N)=NP(O)(O)=O)=O
InChI	1/C4H10N3O5P/c1-7(2-3(8)9)4(5)6-13(10,11)12/h2H2,1H3,(H,8,9)(H4,5,6,10,11,12)/f/h8,10-11H,5H2/b6-4+
Properties
Molecular formula	C4H10N3O5P
Molar mass	211.11 g/mol
Y (what is this?)  (verify) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Phosphocreatine, also known as creatine phosphate or PCr (Pcr), is a phosphorylated creatine molecule that serves as a rapidly mobilizable reserve of high-energy phosphates in skeletal muscle and brain: Phosphocreatine can anaerobically donate a phosphate group to ADP to form ATP during the first 2 to 7 seconds following an intense muscular or neuronal effort. On the converse, excess 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 kinases. The presence of creatine kinase (CK-MB, MB for muscle/brain) in plasma is indicative of tissue damage and is used in the diagnosis of myocardial infarction.^[1] The cell's ability to generate phosphocreatine from excess ATP during rest, as well as its use of phosphocreatine for quick regeneration of ATP during intense activity, provides a spatial and temporal buffer of 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, ATP. Phosphocreatine plays a particularly important role in tissues that have high, fluctuating energy demands such as muscle and brain.

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, SAM is required) to creatine (in liver), and phosphorylation by creatine kinase (ATP is required) to phosphocreatine (in muscle); catabolism: hydrolysis to creatinine. Phosphocreatine is synthesized in the liver and transported to the muscle cells, via the bloodstream, for storage.

History

The discovery of phosphocreatine^[2][3] was reported by Grace and Philip Eggleton of the University of Cambridge^[4] and separately by Cyrus Fiske and Yellapragada Subbarow of the Harvard Medical School^[5] in 1927. A few years later David Nachmansohn, working under Meyerhof at the Kaiser Wilhelm Institute in Dahlem, Berlin, contributed to the understanding of the phosphocreatine's role in the cell.^[3]

References

See also

Human Metabolome Database at the University of Alberta

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