alanine(redirected from Ala or A)
Also found in: Dictionary, Thesaurus, Medical.
alanine(ăl`ənēn'), organic compound, one of the 20 amino acidsamino acid
, any one of a class of simple organic compounds containing carbon, hydrogen, oxygen, nitrogen, and in certain cases sulfur. These compounds are the building blocks of proteins.
..... Click the link for more information. commonly found in animal proteins. Only the l-stereoisomer participates in the biosynthesis of proteins (see stereochemistrystereochemistry,
study of the three-dimensional configuration of the atoms that make up a molecule and the ways in which this arrangement affects the physical and chemical properties of the molecule.
..... Click the link for more information. ). Its side chain is a nonpolar, hydrophobic methyl group. The low reactivity of the amino acid permits silk, a protein which contains some 30% alanine, to have a simple, elongated structure with few cross-links. This contributes to the desirable features of the fiber-strength, resistance to stretching, and flexibility. Alanine is not essential to the human diet, since it can be synthesized from other cellular metabolites. It was discovered in protein in 1875.
C3H7NO2 A white, crystalline, nonessential amino acid of the pyruvic acid family.