L-Threonine tert-butyl ester is a protected form of L-Threonine (T405500). L-Threonine is an essential amino acid that is commonly used as a feed and food additive. L-Threonine is produced in mass quantities by mutant Escherichia coli strains for research and food nutrition purposes. L-Threonine can be naturally found in fish and poultry, and is incorporated in some important proteins in the human body (such as hemoglobin and insulin).