Alanine

Either of two amino acids, one of which (a-alanine) is a constituent of proteins. An especially rich source of a-alanine is silk fibroin, from which the amino acid was first isolated in 1879. Alanine is one of several so-called nonessential amino acids for birds and mammals; i.e., they can synthesize it from pyruvic acid (formed in the breakdown of carbohydrates) and do not require