Aspartic acid

Aspartic acid

Names
IUPAC names Trivial: Aspartic acid Systematic: 2-Aminobutanedioic acid
Other names Aminosuccinic acid, asparagic acid, asparaginic acid
Identifiers
CAS Number	617-45-8 Y 56-84-8 (L-isomer) N 1783-96-6 (D-isomer) N
3D model (Jmol)	Interactive image Interactive image
ChEBI	CHEBI:22660 Y
ChEMBL	ChEMBL139661 Y
ChemSpider	411 Y
ECHA InfoCard	100.000.265
EC Number	200-291-6
KEGG	C16433 Y
PubChem	424
UNII	28XF4669EP Y
InChI InChI=1S/C4H7NO4/c5-2(4(8)9)1-3(6)7/h2H,1,5H2,(H,6,7)(H,8,9) Y Key: CKLJMWTZIZZHCS-UHFFFAOYSA-N Y InChI=1/C4H7NO4/c5-2(4(8)9)1-3(6)7/h2H,1,5H2,(H,6,7)(H,8,9) Key: CKLJMWTZIZZHCS-UHFFFAOYAE
SMILES O=C(O)CC(N)C(=O)O C(C(C(=O)O)N)C(=O)O
Properties
Chemical formula	C4H7NO4
Molar mass	133.10 g·mol−1
Appearance	colourless crystals
Density	1.7 g/cm3
Melting point	270 °C (518 °F; 543 K)
Boiling point	324 °C (615 °F; 597 K) (decomposes)
Solubility in water	4.5 g/L
Acidity (pKa)	3.9
Magnetic susceptibility (χ)	-64.2·10−6 cm3/mol
Hazards
Safety data sheet	See: data page
NFPA 704	1 1 0
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Aspartic acid (abbreviated as Asp or D; encoded by the codons [GAU and GAC]), also known as aspartate, is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH+
3 form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO⁻ form under biological conditions), and a side chain CH₂COOH. Under physiological conditions in proteins the sidechain usually occurs as the negatively charged aspartate form, −COO⁻. It is semi-essential in humans, meaning the body can synthesize it from oxaloacetate.

In proteins aspartate sidechains are often hydrogen bonded, often as asx turns or asx motifs, which often occur at the N-termini of alpha helices.

Asp's L-isomer is one of the 23 proteinogenic amino acids, i.e., the building blocks of proteins. Asp (and glutamic acid) is classified as acidic, with a pK_a of 3.9, however in a peptide this is highly dependent on the local environment (as with all amino acids), and could be as high as 14. Asp is pervasive in biosynthesis.

L-aspartic acid is one of the two main ingredients of the artificial sweetener aspartame, along with L-phenylalanine.

Aspartic acid was first discovered in 1827 by Auguste-Arthur Plisson and Étienne Ossian Henry, derived from asparagine, which had been isolated from asparagus juice in 1806, by boiling with a base.

There are two forms or enantiomers of aspartic acid. The name "aspartic acid" can refer to either enantiomer or a mixture of two. Of these two forms, only one, "L-aspartic acid", is directly incorporated into proteins. 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.