A key gluconeogenic amino acid is:

Alanine is a key gluconeogenic amino acid. The rate of hepatic gluconeogenesis from alanine is far higher than from all other amino acids. The capacity of the liver for gluconeogenesis from alanine does not reach saturation until the alanine concentration reaches 20 to 30 times its normal physiologic level. Ref: Harper’s illustrated biochemistry. 30th edition page no: 289