Patent ID: 8785147

Claim:
A method for analyzing the L-threonine contained in a specimen, comprising: A) mixing a sample comprising a specimen and L-threonine dehydrogenase, with the coenzyme NAD + ; and B) determining the quantity of a product after a time period, wherein the product is selected from the group consisting of NADH and 2-amino-3-oxybutyric acid; wherein said L-threonine dehydrogenase has L-threonine dehydrogenase activity that is oxidative and specific for L-threonine to 2-amino-3-oxobutyric acid, and is selected from the group consisting of: (i) L-threonine dehydrogenase from Cupriavidus necator; (ii) a protein comprising the amino acid sequence of SEQ ID NO: 1; (iii) a protein comprising the amino acid sequence of SEQ ID NO: 1, but having from 1 to 30 amino acid deletions, substitutions, and/or additions; and (iv) a protein comprising an amino acid sequence having 90% or greater homology with the amino acid sequence of SEQ ID NO: 1.