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(Redirected from Aspartate)
'Aspartic acid' is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CO2H. The L-isomer is a protonated varient of one of the 20 proteinogenic amino acids, i.e. the building blocks of proteins. Its three letter code is asp, its one letter code is D, and its codons are GAU and GAC.[1] It is classified as an acidic amino acid, together with glutamic acid. Aspartic acid is pervasive in biosynthesis.
Aspartic acid is non-essential in mammals, being produced from oxaloacetate by transamination. In plants and microorganisms, aspartic acid is the precursor to several amino acids, including four that are essential: methionine, threonine, isoleucine, and lysine. The conversion of aspartic acid to these other amino acids begins with reduction of aspartic acid to its "semialdehyde," HO2CCH(NH2)CH2CHO.[2] Asparagine is derived from aspartic acid via transamidation:
:HO2CCH(NH2)CH2CO2H + ''G''C(O)NH2 HO2CCH(NH2)CH2CONH2 + ''G''C(O)OH
(where ''G''C(O)NH2 and ''G''C(O)OH are glutamine and glutamic acid, respectively)
Aspartic acid 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. Aspartic acid donates one nitrogen atom in the biosynthesis of inositol, the precursor to the purine bases.
Aspartate (the conjugate base of aspartic acid) stimulates NMDA receptors, though not as strongly as the amino acid neurotransmitter glutamate does.[3] It serves as an excitatory neurotransmitter in the brain and is an excitotoxin.
As a neurotransmitter, aspartic acid may provide resistance to fatigue and thus lead to endurance, although the evidence to support this idea is not strong.
Racemic aspartic acid can be synthesized from diethyl sodium phthalimidomalonate, (C6H4(CO)2NC(CO2Et)2).[4]
1. Nomenclature and Symbolism for Amino Acids and Peptides IUPAC-IUBMB Joint Commission on Biochemical Nomenclature
2. Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. ISBN 1-57259-153-6.
3. Philip E. Chen, Matthew T. Geballe, Phillip J. Stansfeld, Alexander R. Johnston, Hongjie Yuan, Amanda L. Jacob, James P. Snyder, Stephen F. Traynelis, and David J. A. Wyllie. 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. ''Molecular Pharmacology''. Volume 67, Pages 1470-1484.
4. Dunn, M. S.; Smart, B. W. “DL-Aspartic Acid”Organic Syntheses, Collected Volume 4, p.55 (1963). http://www.orgsyn.org/orgsyn/pdfs/CV4P0055.pdf
★ Aspartate transaminase
★ Sodium poly(aspartate), a synthetic polyamide
'Aspartic acid' is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CO2H. The L-isomer is a protonated varient of one of the 20 proteinogenic amino acids, i.e. the building blocks of proteins. Its three letter code is asp, its one letter code is D, and its codons are GAU and GAC.[1] It is classified as an acidic amino acid, together with glutamic acid. Aspartic acid is pervasive in biosynthesis.
| Contents |
| Role in biosynthesis of amino acids |
| Other biochemical roles |
| Neurotransmitter |
| Synthesis |
| References |
| See also |
| External links |
Role in biosynthesis of amino acids
Aspartic acid is non-essential in mammals, being produced from oxaloacetate by transamination. In plants and microorganisms, aspartic acid is the precursor to several amino acids, including four that are essential: methionine, threonine, isoleucine, and lysine. The conversion of aspartic acid to these other amino acids begins with reduction of aspartic acid to its "semialdehyde," HO2CCH(NH2)CH2CHO.[2] Asparagine is derived from aspartic acid via transamidation:
:HO2CCH(NH2)CH2CO2H + ''G''C(O)NH2 HO2CCH(NH2)CH2CONH2 + ''G''C(O)OH
(where ''G''C(O)NH2 and ''G''C(O)OH are glutamine and glutamic acid, respectively)
Other biochemical roles
Aspartic acid 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. Aspartic acid donates one nitrogen atom in the biosynthesis of inositol, 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.[3] It serves as an excitatory neurotransmitter in the brain and is an excitotoxin.
As a neurotransmitter, aspartic acid may provide resistance to fatigue and thus lead to endurance, although the evidence to support this idea is not strong.
Synthesis
Racemic aspartic acid can be synthesized from diethyl sodium phthalimidomalonate, (C6H4(CO)2NC(CO2Et)2).[4]
References
1. Nomenclature and Symbolism for Amino Acids and Peptides IUPAC-IUBMB Joint Commission on Biochemical Nomenclature
2. Nelson, D. L.; Cox, M. M. "Lehninger, Principles of Biochemistry" 3rd Ed. Worth Publishing: New York, 2000. ISBN 1-57259-153-6.
3. Philip E. Chen, Matthew T. Geballe, Phillip J. Stansfeld, Alexander R. Johnston, Hongjie Yuan, Amanda L. Jacob, James P. Snyder, Stephen F. Traynelis, and David J. A. Wyllie. 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. ''Molecular Pharmacology''. Volume 67, Pages 1470-1484.
4. Dunn, M. S.; Smart, B. W. “DL-Aspartic Acid”Organic Syntheses, Collected Volume 4, p.55 (1963). http://www.orgsyn.org/orgsyn/pdfs/CV4P0055.pdf
See also
★ Aspartate transaminase
★ Sodium poly(aspartate), a synthetic polyamide
External links
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