Aspartic acid
- Aspartic
- Aminosuccinic acid
- 2- Aminobutandisäure
- ( S) - ( )- aminosuccinic acid
- (S)- aminosuccinic acid
- Abbreviations: Asp ( Three letter code)
- D ( single letter code )
- 56-84-8 (L- enantiomer)
- 1783-96-6 (D - enantiomer)
- 617-45-8 (DL- aspartic acid)
V06DD
Colorless leaflets or rods
Fixed
270-271 ° C ( decomposition)
- PK, α -COOH = 1.99
- PK, β -COOH = 3.90
- PK, NH2 = 9.90
Poorly in water ( 4 g · l-1 at 20 ° C)
Template: Infobox chemical / molecular formula search available
Aspartic acid, abbreviated to Asp or D, is one of the 20 proteinogenic α -amino acids in their natural L-form. The acid anion is referred to as aspartate ion. Since amino acids in the body are normally present more deprotonated, only the term L-aspartate is used frequently in biochemistry instead of L -aspartic acid. In this article, the information on the physiology relate solely to the L- aspartic acid [ synonym: (S) -aspartic acid ]. If it is mentioned in this text and in the scientific literature without any addition " aspartic acid " is always meant L- aspartic acid. The racemic DL -aspartic acid [ Synonym: ( RS)- aspartic acid ] and the enantiomerically pure D -aspartic acid [ synonym: (R) -aspartic acid ] are synthetically accessible and only have little practical significance. The partial racemization of L- amino acids can be used for amino acid dating - are used - a dating fossil bone material.
Properties
Aspartic acid is acidic due to its two carboxyl groups. Therefore, this amino acid lies physiologically - depending on the pH value - usually as an inner salt in the form of an aspartate ago.
Occurrence
L-aspartic acid was first obtained by the hydrolysis of asparagine that is present in the legume seedlings. Vegetables Asparagus (Asparagus officinalis) also contains relatively high levels of L- aspartic acid.
Biosynthesis and industrial production
The biosynthesis of L- aspartic acid occurs, for example from the homologous keto acid oxaloacetate by transamination. Industrially, L- aspartic acid is obtained by means of biotechnological processes enantioselective addition of ammonia to the C = C double bond of fumaric acid. Here, a microorganism with the enzyme L- aspartase is used.
Functions
L- Aspartate ( the conjugate base of aspartic acid ) is in vertebrates act as a transmitter together with glutamic acid in more than 50 percent of all synapses of the central nervous system, including the climbing fibers of the cerebellum and the mossy fibers of the hippocampal formation. It works via the stimulation of the NMDA receptors. However the effect is not as strong as with glutamate.
In addition, L -aspartic acid is combined in the urea cycle by the enzyme argininosuccinate synthetase with citrulline with cleavage of ATP to AMP and PPi to argininosuccinate. This is then split by the argininosuccinate lyase in the L- arginine, and fumarate. L-arginine is then from urea as fumarate is converted back in the TCA cycle to oxaloacetic, can be transaminated to the back L- aspartate ( Aminogruppenübertragung of α -amino acids via transamination of oxaloacetate on urea ).
Use
Significant amounts of L-aspartic acid are used for the production of the sweetener aspartame. Further L-aspartic acid is used as starting material for the stereoselective synthesis of a variety of other chiral organic- chemical compounds. N-substituted polyaspartic esters are used as reactive components in modern paint systems.
Furthermore, L-aspartic acid is used as a component of infusion solutions for parenteral nutrition and salt formers.