1. A white crystalline amino acid CH3CH(NH2)COOH that is known in three optically different forms, that is formed by the hydrolysis of proteins and made synthetically, and that takes part in transamination reactions in the living organism; a-amino-propionic acid.
2. A white crystalline amino acid NH2CH2CH2COOH found in muscle in the form of carnosine and anserine, made synthetically, and used in making pantothenic acid: a-amino-propionic acid.
ref: Webster's International Unabridged Dictionary