Home Page   
Home PageE
Today is
Java Applets
BIOLOGY
CHEMISTRY
HIGH SCHOOL CHEMISTRY
BIOCHEMISTRY
MATHEMATICS
JUST MOLECULES
PHYSICS

 

 

interactive Library

asparagine molecule  

Asparagine

Asparagine (abbreviated as Asn or N; Asx or B represent either asparagine or aspartic acid) is one of the 20 most common natural amino acids on Earth. It has carboxamide as the side chain's functional group. It is not an essential amino acid. Its codons are AAU and AAC.[1] A reaction between asparagine and reducing sugars or reactive carbonyls produces acrylamide (acrylic amide) in food when heated to sufficient temperature. These products occur in baked goods such as french fries, potato chips, and roasted coffee.

History

Asparagine was first isolated in 1806 from asparagus juice, in which it is abundant -- hence its name -- becoming the first amino acid to be isolated. The characteristic smell observed in the urine of individuals after their consumption of asparagus is attributed to various metabolic byproducts of asparagine.

Structural function in proteins

Since the asparagine side chain can form hydrogen bond interactions with the peptide backbone, asparagine residues are often found near the beginning and the end of alpha-helices, and in turn motifs in beta sheets. Its role can be thought as "capping" the hydrogen bond interactions which would otherwise be satisfied by the polypeptide backbone. Glutamines, with an extra methylene group, have more conformational entropy and thus are less useful in this regard. Asparagine also provides key sites for N-linked glycosylation, modification of the protein chain with the addition of carbohydrate chains.

Dietary Sources

Asparagine is not an essential amino acid, which means that it can be synthesized from central metabolic pathway intermediates in humans and is not required in the diet. Asparagine is found in: Animal sources: dairy, whey, beef, poultry, eggs, fish, lactalbumin, seafood Vegetarian sources: asparagus, potatoes, legumes, nuts, seeds, soy, whole grains

References

IUPAC-IUBMB Joint Commission on Biochemical Nomenclature. "Nomenclature and Symbolism for Amino Acids and Peptides". Recommendations on Organic & Biochemical Nomenclature, Symbols & Terminology etc. Retrieved on 2007-05-17.

 

Some or all of this text has been obtained from Wikipedia, the free encyclopedia. All text is available under the terms of the GNU Free Documentation License (see Copyrights for details). Disclaimers. Wikipedia is powered by MediaWiki, an open source wiki engine.

3d Molecules
COMPLETE DATABASE OF 3D MOLECULES
WATER
ICE
METHANE
CARBON MONOXIDE
DIAMOND
FULLERENE
SALT
SOAP
DNA
--- 3D molecules using Jmol

 

 


Questions or Comments?
Copyright © 1999 EdInformatics.com
All Rights Reserved.