Pronunciation: (al'u-nēn", -nin), [key]
any of several isomers of a colorless, crystalline, water-soluble amino acid, CH3CH(NH2)COOH, found in many proteins and produced synthetically: used chiefly in biochemical research. Abbr.: Ala; Symbol: A
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.