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Alanine

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Alanine (Ala, A) also 2-aminopropanoic acid is a non-essential α-amino acid. It exists as two distinct enantiomers - L-alanine and D-alanine. L-alanine is one of the 20 amino acids most widely used in protein synthesis, second to leucine, accounting for 7.8% of the primary structure in a sample of 1,150 proteins Template:Ref N. D-alanine occurs in bacterial cell walls and in some peptide antibiotics.

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.

Biosynthesis

Alanine is most commonly made by reductive amination of pyruvate. Because transamination reactions are readily reversible, alanine can be easily formed from pyruvate and thus has close links to metabolic pathways such as glycolysis, gluconeogenesis, and the citric acid cycle.

Function

The methyl group of alanine is very non-reactive, and is thus rarely directly involved in protein function. However, alanine can play a role in substrate recognition or specificity, particularly in interactions with other non-reactive atoms such as carbon.

It goes through alanine cycle to generate glucose from protein.

Sources

Any protein-containing food such as meat, poultry, fish, eggs or dairy products is rich in alanine.

References

  1. Template:Note N 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.

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