Aspartic acid

Aspartic acid
Identifiers
CAS number 617-45-8 YesY
56-84-8 (L-isomer)
1783-96-6 (D-isomer)
PubChem 424
ChemSpider 411 YesY
UNII 28XF4669EP YesY
EC-number 200-291-6
KEGG C16433 YesY
ChEBI CHEBI:22660 YesY
ChEMBL CHEMBL139661 YesY
Jmol-3D images Image 1
Image 2
Properties
Molecular formula C4H7NO4
Molar mass 133.1 g mol−1
Hazards
MSDS External MSDS
EU Index not listed
Supplementary data page
Structure and
properties
n, εr, etc.
Thermodynamic
data
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Aspartic acid (abbreviated as Asp or D; Asx or B represent either aspartic acid or asparagine)[2] is an α-amino acid with the chemical formula HOOCCH(NH2)CH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins. Its codons are GAU and GAC.

Aspartic acid is, together with glutamic acid, classified as an acidic amino acid with a pKa of 4.0. Aspartate is pervasive in biosynthesis. As with all amino acids, the presence of acid protons depends on the residue's local chemical environment and the pH of the solution.

Contents

Discovery

Aspartic acid was first discovered in 1827 by Plisson, synthesized by boiling asparagine (which had been isolated from asparagus juice in 1806) with a base.[3]

Forms and nomenclature

The term "aspartic acid" refers to either of two forms or a mixture of two.[2] Of these two forms, only one, "L-aspartic acid", is directly incorporated into amino acids. The biological roles of its counterpart, "D-aspartic acid" are more limited. Where enzymatic synthesis will produce one or the other, most chemical syntheses will produce both forms, "DL-aspartic acid," known as a racemic mixture.

Role in biosynthesis of amino acids

Aspartate is non-essential in mammals, being produced from oxaloacetate by transamination. It can also be made in the Urea Cycle from Ornithine and Citrulline. In plants and microorganisms, aspartate is the precursor to several amino acids, including four that are essential for humans: methionine, threonine, isoleucine, and lysine. The conversion of aspartate to these other amino acids begins with reduction of aspartate to its "semialdehyde," O2CCH(NH2)CH2CHO.[4] Asparagine is derived from aspartate via transamidation:

-O2CCH(NH2)CH2CO2- + GC(O)NH3+ O2CCH(NH2)CH2CONH3+ + GC(O)O

(where GC(O)NH2 and GC(O)OH are glutamine and glutamic acid, respectively)

Other biochemical roles

Aspartate is also a metabolite in the urea cycle and participates in gluconeogenesis. It carries reducing equivalents in the malate-aspartate shuttle, which utilizes the ready interconversion of aspartate and oxaloacetate, which is the oxidized (dehydrogenated) derivative of malic acid. Aspartate donates one nitrogen atom in the biosynthesis of inosine, the precursor to the purine bases.

Neurotransmitter

Aspartate (the conjugate base of aspartic acid) stimulates NMDA receptors, though not as strongly as the amino acid neurotransmitter glutamate does.[5]

Sources

Dietary sources

Aspartic acid is not an essential amino acid, which means that it can be synthesized from central metabolic pathway intermediates in humans. Aspartic acid is found in:

Chemical synthesis

Racemic aspartic acid can be synthesized from diethyl sodium phthalimidomalonate, (C6H4(CO)2NC(CO2Et)2).[6]

The major disadvantage of the above technique is that equimolar amounts of each enantiomer are made, the body only utilises L-amino acids. Using biotechnology it is now possible to use immobilised enzymes to create just one type of enantiomer owing to their stereospecificity. Aspartic acid is made synthetically using ammonium fumarate and aspartase from E.coli, E.coli usually breaks down the aspartic acid as a nitrogen source but using excess amounts of ammonium fumarate a reversal of the enzyme's job is possible, and so aspartic acid is made to very high yields, 98.7 mM from 1 M.

References

  1. ^ a b "862. Aspartic acid". The Merck Index (11th ed.). 1989. p. 132. ISBN 091191028X. 
  2. ^ a b "Nomenclature and symbolism for amino acids and peptides (IUPAC-IUB Recommendations 1983)", Pure Appl. Chem. 56 (5): 595–624, 1984, doi:10.1351/pac198456050595 .
  3. ^ R.H.A. Plimmer (1912) [1908]. R.H.A. Plimmer & F.G. Hopkins. ed. The chemical composition of the proteins. Monographs on biochemistry. Part I. Analysis (2nd ed.). London: Longmans, Green and Co.. p. 112. http://books.google.com/?id=7JM8AAAAIAAJ&pg=PA112. Retrieved January 18, 2010. 
  4. ^ Lehninger, Albert L.; Nelson, David L.; Cox, Michael M. (2000), Principles of Biochemistry (3rd ed.), New York: W. H. Freeman, ISBN 1-57259-153-6 .
  5. ^ Chen, Philip E.; Geballe, Matthew T.; Stansfeld, Phillip J.; Johnston, Alexander R.; Yuan, Hongjie; Jacob, Amanda L.; Snyder, James P.; Traynelis, Stephen F. et al. (2005). "Structural Features of the Glutamate Binding Site in Recombinant NR1/NR2A N-Methyl-D-aspartate Receptors Determined by Site-Directed Mutagenesis and Molecular Modeling". Mol. Pharmacol. 67 (5): 1470–84. doi:10.1124/mol.104.008185. PMID 15703381. http://molpharm.aspetjournals.org/cgi/content/full/67/5/1470. 
  6. ^ Dunn, M. S.; Smart, B. W. (1950), "DL-Aspartic Acid", Org. Synth. 30: 7, http://www.orgsyn.org/orgsyn/orgsyn/prepContent.asp?prep=CV4P0055 ; Coll. Vol. 4: 55 .

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See also


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Look at other dictionaries:

  • aspartic acid — [as pär′tik] n. [coined from ASPARAGUS] a nonessential amino acid, COOHCH2CH(NH2)COOH …   English World dictionary

  • aspartic acid — HOOC CH2 CH(NH2) COOH; the l isomer is one of the amino acid s occurring naturally in proteins. The d isomer is found in cell walls of many bacteria. * * * as·par·tic acid ə .spärt ik n a crystalline amino acid C4H7NO4 that is obtained from many… …   Medical dictionary

  • aspartic acid — /euh spahr tik/, Biochem. a nonessential amino acid, C4H7NO4, produced by the hydrolysis of asparagine and proteins, found chiefly in young sugar cane and sugar beet molasses, and used in the preparation of culture media and as a dietary… …   Universalium

  • aspartic acid — asparto rūgštis statusas T sritis chemija formulė HOOCCH₂CH(NH₂)COOH santrumpa( os) Asp, D atitikmenys: angl. asparagic acid; aspartic acid rus. аспарагиновая кислота ryšiai: sinonimas – aminobutano dirūgštis …   Chemijos terminų aiškinamasis žodynas

  • aspartic acid — /əspatɪk ˈæsəd/ (say uhspahtik asuhd) noun an amino acid, HOO CCH2 CH(NH3+)COO , found especially in young sugar cane and sugar beet. {Aspartic, from asparagus, because it is obtained from an amino acid found in asparagus} …   Australian English dictionary

  • aspartic acid — [ə spα:tɪk] noun Biochemistry an acidic amino acid present in many proteins and in sugar cane, important in the metabolism of nitrogen in animals and also acting as a neurotransmitter. Origin C19: aspartic from Fr. aspartique, L. asparagus (see… …   English new terms dictionary

  • aspartic acid — noun a crystalline amino acid found in proteins and occurring naturally in sugar beets and sugar cane • Hypernyms: ↑amino acid, ↑aminoalkanoic acid …   Useful english dictionary

  • aspartic acid — noun A nonessential amino acid, L α amino succinic acid, (CHNO), found in animal protein and in sugar beet etc. Syn: Asp See Also: aspartate …   Wiktionary

  • aspartic acid — noun Etymology: International Scientific Vocabulary, irregular from Latin asparagus Date: 1863 a crystalline amino acid C4H7NO4 found especially in plants …   New Collegiate Dictionary

  • aspartic acid — nonessential crystalline dicarboxylic amino acid found in plant proteins and manufactured within humans and animals (Biochemistry) …   English contemporary dictionary


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