L-threonine is an optically active form of threonine having L-configuration. ... It is an aspartate family amino acid, a proteinogenic amino acid, a threonine and a L-alpha-amino acid. It is a conjugate base of a L-threoninium.

Threonine, an essential amino acid, is a hydrophilic molecule. Threonine is an other hydroxyl-containing amino acid. It differs from serine by having a methyl substituent in place of one of the hydrogens on the β carbon and it differs from valine by replacement of a methyl substituent with a hydroxyl group.

L THREONINE FOR BIOCHEMISTRY