In the kidneys, the enzyme AGAT catalyzes the conversion of two amino acids — arginine and glycine — into guanidinoacetate (also called glycocyamine or GAA), which is then transported in the blood to the liver. A methyl group is added to GAA from the amino acid methionine by the enzyme GAMT, forming non-phosphorylated creatine. This is then released into the blood by the liver where it travels mainly to the muscle cells (95% of the body's creatine is in muscles), and to a lesser extent the brain, heart, and pancreas. Once inside the cells it is transformed into phosphocreatine by the enzyme complex creatine kinase.
Phosphocreatine is able to donate its phosphate group to convert adenosine diphosphate (ADP) into adenosine triphosphate (ATP). This process is an important component of all vertebrates' bioenergetic systems. For instance, while the human body only produces 250 g of ATP daily, it recycles its entire body weight in ATP each day through creatine phosphate.
Phosphocreatine can be broken down into creatinine, which is then excreted in the urine. A 70 kg man contains around 120 g of creatine, with 40% being the unphosphorylated form and 60% as creatine phosphate. Of that amount, 1–2% is broken down and excreted each day as creatinine.
Phosphocreatine is used intravenously in hospitals in some parts of the world for cardiovascular problems under the name Neoton, and also used by some professional athletes, as it is not a controlled substance.
Functionedit
Phosphocreatine can anaerobically donate a phosphate group to ADP to form ATP during the first five to eight seconds of a maximal muscular effort. [citation needed] Conversely, excess ATP can be used during a period of low effort to convert creatine back 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, creatine kinase myocardial band) in blood 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.
^Schlattner U, Tokarska-Schlattner M, Wallimann T (2006). "Mitochondrial creatine kinase in human health and disease". Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease. 1762 (2): 164–180. doi:10.1016/j.bbadis.2005.09.004. PMID 16236486.
^Saks, Valdur (2007). Molecular system bioenergetics: energy for life. Weinheim: Wiley-VCH. p. 2. ISBN978-3-527-31787-5.
^ abOchoa, Severo (1989). Sherman, E. J.; National Academy of Sciences (eds.). David Nachmansohn. Biographical Memoirs. Vol. 58. National Academies Press. pp. 357–404. ISBN978-0-309-03938-3.
^Eggleton, Philip; Eggleton, Grace Palmer (1927). "The inorganic phosphate and a labile form of organic phosphate in the gastrocnemius of the frog". Biochemical Journal. 21 (1): 190–195. doi:10.1042/bj0210190. PMC1251888. PMID 16743804.
^Fiske, Cyrus H.; Subbarao, Yellapragada (1927). "The nature of the 'inorganic phosphate' in voluntary muscle". Science. 65 (1686): 401–403. Bibcode:1927Sci....65..401F. doi:10.1126/science.65.1686.401. PMID 17807679.
phosphocreatine, also, known, creatine, phosphate, phosphorylated, form, creatine, that, serves, rapidly, mobilizable, reserve, high, energy, phosphates, skeletal, muscle, myocardium, brain, recycle, adenosine, triphosphate, energy, currency, cell, names, iupa. Phosphocreatine also known as creatine phosphate CP or PCr Pcr is a phosphorylated form of creatine that serves as a rapidly mobilizable reserve of high energy phosphates in skeletal muscle myocardium and the brain to recycle adenosine triphosphate the energy currency of the cell Phosphocreatine Names IUPAC name N Methyl N phosphonocarbamimidoyl glycine Other names Creatine phosphate phosphorylcreatine creatine P phosphagen fosfocreatine Identifiers CAS Number 67 07 2 Y 3D model JSmol Interactive imageInteractive image Abbreviations PCr Beilstein Reference 1797096 ChEBI CHEBI 17287 ChEMBL ChEMBL1204644 ChemSpider 567 Y DrugBank DB13191 ECHA InfoCard 100 000 585 EC Number 200 643 9 KEGG C02305 Y PubChem CID 587 UNII 020IUV4N33 Y CompTox Dashboard EPA DTXSID0058776 InChI InChI 1S 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 NKey DRBBFCLWYRJSJZ UHFFFAOYSA N NInChI 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 Key DRBBFCLWYRJSJZ UHFFFAOYAF SMILES OC CN C C N NP O O O OCN CC O O C N NP O O O Properties Chemical formula C 4H 10N 3O 5P Molar mass 211 114 g mol 1 Pharmacology ATC code C01EB06 WHO Hazards GHS labelling Pictograms Signal word Warning Hazard statements H315 H319 H335 Precautionary statements P261 P264 P271 P280 P302 P352 P304 P340 P305 P351 P338 P312 P321 P332 P313 P337 P313 P362 P403 P233 P405 P501 Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N verify what is Y N Infobox references Contents 1 Chemistry 2 Function 3 History 4 References 5 External linksChemistry editIn the kidneys the enzyme AGAT catalyzes the conversion of two amino acids arginine and glycine into guanidinoacetate also called glycocyamine or GAA which is then transported in the blood to the liver A methyl group is added to GAA from the amino acid methionine by the enzyme GAMT forming non phosphorylated creatine This is then released into the blood by the liver where it travels mainly to the muscle cells 95 of the body s creatine is in muscles and to a lesser extent the brain heart and pancreas Once inside the cells it is transformed into phosphocreatine by the enzyme complex creatine kinase Phosphocreatine is able to donate its phosphate group to convert adenosine diphosphate ADP into adenosine triphosphate ATP This process is an important component of all vertebrates bioenergetic systems For instance while the human body only produces 250 g of ATP daily it recycles its entire body weight in ATP each day through creatine phosphate Phosphocreatine can be broken down into creatinine which is then excreted in the urine A 70 kg man contains around 120 g of creatine with 40 being the unphosphorylated form and 60 as creatine phosphate Of that amount 1 2 is broken down and excreted each day as creatinine Phosphocreatine is used intravenously in hospitals in some parts of the world for cardiovascular problems under the name Neoton and also used by some professional athletes as it is not a controlled substance Function editPhosphocreatine can anaerobically donate a phosphate group to ADP to form ATP during the first five to eight seconds of a maximal muscular effort citation needed Conversely excess ATP can be used during a period of low effort to convert creatine back 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 creatine kinase myocardial band in blood 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 History editThe 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 edit Schlattner U Tokarska Schlattner M Wallimann T 2006 Mitochondrial creatine kinase in human health and disease Biochimica et Biophysica Acta BBA Molecular Basis of Disease 1762 2 164 180 doi 10 1016 j bbadis 2005 09 004 PMID 16236486 Saks Valdur 2007 Molecular system bioenergetics energy for life Weinheim Wiley VCH p 2 ISBN 978 3 527 31787 5 a b Ochoa Severo 1989 Sherman E J National Academy of Sciences eds David Nachmansohn Biographical Memoirs Vol 58 National Academies Press pp 357 404 ISBN 978 0 309 03938 3 Eggleton Philip Eggleton Grace Palmer 1927 The inorganic phosphate and a labile form of organic phosphate in the gastrocnemius of the frog Biochemical Journal 21 1 190 195 doi 10 1042 bj0210190 PMC 1251888 PMID 16743804 Fiske Cyrus H Subbarao Yellapragada 1927 The nature of the inorganic phosphate in voluntary muscle Science 65 1686 401 403 Bibcode 1927Sci 65 401F doi 10 1126 science 65 1686 401 PMID 17807679 External links editHuman Metabolome Database at the University of Alberta Retrieved from https en wikipedia org w index php title Phosphocreatine amp oldid 1142126049, wikipedia, wiki, book, books, library,
