ALANINE


'Alanine' is an α-amino acid with the chemical formula HO2CCH(NH2)CH3. The L-isomer is one of the 20 proteinogenic amino acids, i.e. the building blocks of proteins. Its three letter code is ala, its one letter code is A, and its codons are GCU, GCC, GCA, and GCG.[1] It is classified as an nonpolar amino acid. L-alanine is second only to leucine, accounting for 7.8% of the primary structure in a sample of 1,150 proteins . D-alanine occurs in bacterial cell walls and in some peptide antibiotics.

Contents
Structure
Biosynthesis
Sources
References
External links

Structure


The α-carbon atom of alanine is bound with a methyl group (-CH3), making it one of the simplest α-amino acids with respect to molecular structure and also resulting in alanine being classified as an aliphatic amino acid. The methyl group of alanine is non-reactive and is thus almost never directly involved in protein function.

Biosynthesis


Alanine is most commonly produced by reductive amination of pyruvate. Because transamination reactions are readily reversible and pyruvate pervasive, alanine can be easily formed and thus has close links to metabolic pathways such as glycolysis, gluconeogenesis, and the citric acid cycle. It also arises together with lactate and generate glucose from protein via the alanine cycle.

Sources


Any protein-containing food such as meat, poultry, fish, eggs or dairy products is rich in alanine. Racemic alanine can be prepared via the addition of hydrogen cyanide and ammonia to acetaldehyde by the Strecker reaction.[2]

References


# Doolittle RF (1989). "Redundancies in protein sequences" in ''Prediction of Protein Structures and the Principles of Protein Conformation''. (Fasman GD, ed.), pp 599-623, Plenum Press, New York.
1. Nomenclature and Symbolism for Amino Acids and Peptides IUPAC-IUBMB Joint Commission on Biochemical Nomenclature
2. Kendall, E. C.; McKenzie, B. F. “dl-Alanine” Organic Syntheses, Collected Volume 1, p.21 (1941).http://www.orgsyn.org/orgsyn/pdfs/CV1P0021.pdf

External links



Computational Chemistry Wiki

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