| 词条 | Pyroglutamic acid |
| 释义 |
| Verifiedfields = changed | Watchedfields = changed | verifiedrevid = 464377606 | ImageFile = Pyroglutamic acid.svg | ImageSize = 140px | PIN = 5-Oxoproline | SystematicName = 5-Oxopyrrolidine-2-carboxylic acid | OtherNames = {{ubl|2-Pyrrolidone-5-carboxylic acid| Pidolic acid |5-Oxo-proline}} | Section1 = {{Chembox Identifiers | IUPHAR_ligand = 4703 | Abbreviations = Glp | InChI = 1S/C5H7NO3/c7-4-2-1-3(6-4)5(8)9/h3H,1-2H2,(H,6,7)(H,8,9)/t3-/m0/s1 | InChIKey1 = ODHCTXKNWHHXJC-VKHMYHEASA-N | InChI1 = 1S/C5H7NO3/c7-4-2-1-3(6-4)5(8)9/h3H,1-2H2,(H,6,7)(H,8,9)/t3-/m0/s1 | CASNo = 149-87-1 | CASNo_Comment = (R/S) | CASNo_Ref = {{cascite|correct|??}} | CASNo1_Ref = {{cascite|correct|??}} | CASNo1 = 4042-36-8 | CASNo1_Comment = (R) | CASNo2_Ref = {{cascite|correct|CAS}} | CASNo2 = 98-79-3 | CASNo2_Comment = (S) | PubChem = 499 | PubChem_Comment = (R/S) | PubChem1 = 439685 | PubChem1_Comment = (R) | PubChem2 = 7405 | PubChem2_Comment = (S) | ChemSpiderID2 = 7127 | ChemSpiderID2_Comment = (S) | ChemSpiderID2_Ref = {{chemspidercite|correct|chemspider}} | ChemSpiderID1 = 388752 | ChemSpiderID1_Comment = (R) | ChemSpiderID1_Ref = {{chemspidercite|correct|ChemSpider}} | ChemSpiderID = 485 | ChemSpiderID_Ref = {{chemspidercite|correct|ChemSpider}} | ChemSpiderID_Comment = (R/S) | UNII = SZB83O1W42 | UNII_Ref = {{fdacite|correct|FDA}} | EINECS = 205-748-3 | DrugBank_Ref = {{drugbankcite|changed|drugbank}} | DrugBank = DB03088 | KEGG_Ref = {{keggcite|changed|kegg}} | KEGG = C02237 | MeSHName = Pyrrolidonecarboxylic+acid | ChEBI_Ref = {{ebicite|changed|EBI}} | ChEBI = 16010 | ChEBI_Comment = (R/S) | ChEBI1 = 16924 | ChEBI1_Comment = (R) | ChEBI2 = 18183 | ChEBI2_Comment = (S) | RTECS = TW3710000 | SMILES = O=C(O)[C@H]1NC(=O)CC1 | ChEMBL_Ref = {{ebicite|changed|EBI}} | ChEMBL = 284718 | StdInChI_Ref = {{stdinchicite|changed|chemspider}} | StdInChI = 1S/C5H7NO3/c7-4-2-1-3(6-4)5(8)9/h3H,1-2H2,(H,6,7)(H,8,9) | StdInChIKey_Ref = {{stdinchicite|changed|chemspider}} | StdInChIKey = ODHCTXKNWHHXJC-UHFFFAOYSA-N | Gmelin = 1473408 | Beilstein = 82134 | 3DMet = B01555 | Section2 = {{Chembox Properties | C=5 | H=7 | N=1 | O=3 | MeltingPtC = 184 | LogP = -0.89 | pKa = -1.76, 3.48, 12.76 | pKb = 15.76, 10.52, 1.24 | IsoelectricPt = 0.94}} }} Pyroglutamic acid (also known as PCA, 5-oxoproline, pidolic acid) is a ubiquitous but little studied natural amino acid derivative in which the free amino group of glutamic acid or glutamine cyclizes to form a lactam.[1] The names of pyroglutamic acid conjugate base, anion, salts, and esters are pyroglutamate, 5-oxoprolinate, or pidolate. It is a metabolite in the glutathione cycle that is converted to glutamate by 5-oxoprolinase. Pyroglutamate is found in many proteins including bacteriorhodopsin. N-terminal glutamic acid and glutamine residues can spontaneously cyclize to become pyroglutamate, or enzymatically converted by glutaminyl cyclases.[1] This is one of several forms of blocked N-termini which present a problem for N-terminal sequencing using Edman chemistry, which requires a free primary amino group not present in pyroglutamic acid. The enzyme pyroglutamate aminopeptidase can restore a free N-terminus by cleaving off the pyroglutamate residue.[2] Pyroglutamic acid exists as two distinct enantiomers:
MetabolismAs first discovered in 1882, pyroglutamic acid can be formed by heating glutamic acid at 180 °C, which results in the loss of a molecule of water. In living cells, it is derived from glutathione through the action of an enzyme, γ-glutamyl cyclotransferase.[1] Pyroglutamic acid may function in glutamate storage, and acts to oppose the action of glutamate, including in the brain.[1] It also acts on the brain's cholinergic system;[3] Amyloid β containing pyroglutamic acid is increased in Alzheimer's disease; this may be part of the disease process.[4] Increased levels of pyroglutamic acid in the blood, or 5-oxoprolinuria, can occur following paracetamol overdose, as well as in certain inborn errors of metabolism, causing an acidosis known as high anion gap metabolic acidosis.[5][6] UsesThe sodium salt of pyroglutamic acid — known either as sodium pyroglutamate, sodium PCA, or sodium pidolate — is used for dry skin and hair products, as it is a humectant. It has low toxicity and is not a skin irritant, but its use in products is limited by a high price.[7][8] L-pyroglutamic acid is sold online as a nootropic dietary supplement.[9][10]Magnesium pidolate, the magnesium salt of pyroglutamic acid, is found in some mineral supplements. References1. ^{{citation |last1= Schilling |first1= S. |last2= Wasternack |first2= C. |last3= Demuth |first3= H.U. |title= Glutaminyl cyclases from animals and plants: a case of functionally convergent protein evolution |journal= Biol. Chem. |volume= 389 |issue=8 |pages= 983–91 |year= 2008 |pmid= 18979624 |doi= 10.1515/BC.2008.111}}. {{Protein primary structure}}2. ^{{citation |last1= Podell |first1= David N. |last2= Abraham |first2= George N. |title= A technique for the removal of pyroglutamic acid from the amino terminus of proteins using calf liver pyroglutamate amino peptidase |journal= Biochem. Biophys. Res. Commun. |volume= 81 |issue=1 |pages= 176–85 |year= 1978 |pmid= 26343 |doi= 10.1016/0006-291X(78)91646-7}}. 3. ^{{cite journal|url=http://www.sciencedirect.com/science/article/pii/0278584689901127|title=Nootropic drugs and brain cholinergic mechanisms|journal=Prog Neuropsychopharmacol Biol Psychiatry|date=1989|volume=13 |issue=Supplement 1|pages=S77–88|last1=Pepeu|first1=Giancarlo|last2=Spignoli|first2=Giacomo|doi=10.1016/0278-5846(89)90112-7}} 4. ^{{cite journal|url=http://www.jbc.org/content/286/45/38825.long|journal=J Biol Chem|date=November 11, 2011|volume=286|issue=45|pages=38825–32|doi= 10.1074/jbc.R111.288308|pmid=21965666|title=Pyroglutamate amyloid-β (Aβ): a hatchet man in Alzheimer disease |last1=Jawhar|first1=S|last2=Wirths|first2=O|last3=Bayer|first3=TA|pmc=3234707}} 5. ^1 2 3 {{cite journal|url=http://www.currentscience.ac.in/Volumes/102/02/0288.pdf|title=Pyroglutamic acid: throwing light on a lightly studied metabolite|first1=Akhilesh|last1=Kumar|first2=Anand K.|last2=Bachhawat|volume=102|issue=2|page=208|date=January 25, 2012}} 6. ^{{cite journal|last1=Liss|first1=DB|last2=Paden|first2=MS|last3=Schwarz|first3=ES|last4=Mullins|first4=ME|title=What is the clinical significance of 5-oxoproline (pyroglutamic acid) in high anion gap metabolic acidosis following paracetamol (acetaminophen) exposure?|journal=Clin Toxicol|date=November 2013|volume=51|issue=9|pages=817–27|doi=10.3109/15563650.2013.844822|pmid = 24111553}} 7. ^{{cite web|url=https://www.evidence.nhs.uk/formulary/bnf/current/13-skin/132-emollient-and-barrier-preparations/1321-emollients/proprietary-emollient-preparations/hydromol|title=Hydromol® (Alliance)|work=British National Formulary|accessdate=December 5, 2015}} 8. ^{{cite book|chapter-url=https://books.google.co.uk/books?id=kGTsPEMNLt0C&pg=RA1-PA424|title=Glycerine: A Key Cosmetic Ingredient|chapter=Alternatives to Glycerine|editors=Eric Jungermann, Norman O.V. Sonnta|page=424|isbn=9780824784652|author1=Jungermann|first1=Eric|last2=Sonntag|first2=Norman O.V|date=1991-07-19}} 9. ^{{cite journal|pmc=3875272|title=Inaccurate Serelaxin Chemical Structure|first=Matthew J.|last=DellaVecchia|journal=Pharmacy and Therapeutics|date=December 2013|volume=38|issue=12|page=763|pmid=24391398}} 10. ^{{cite journal|pmc=2398696|title=Utility of Nutraceutical Products Marketed for Cognitive and Memory Enhancement|journal=J Holist Nurs|first1=Graham J.|last1=McDougall, Jr.|first2=Vonnette|last2=Austin-Wells|first3=Teena|last3=Zimmerman|date=December 2005|volume=23|issue=4|pages=415–433|doi=10.1177/0898010105280097|pmid=16251490}} (table 1) 5 : Pyrrolidones|Amino acids|Glutamates|Non-proteinogenic amino acids|Cyclic amino acids |
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