Patent ID: 8802366

Claim:
A method for measuring a glycated protein using a protease enzyme (A) that acts on the glycated protein and fructosyl amino acid oxidase (FAOD) enzyme (B) that specifically detects a glycated amino acid product (C) produced from the glycated protein, the method comprising steps of: i) preparing a reagent (D) in which the protease enzyme (A) and the fructosyl amino acid oxidase (FAOD) enzyme (B) coexist in the absence of the glycated protein; ii) bringing the glycated protein into contact with the reagent (D) to form a reaction mixture so that the protease enzyme (A) acts on the glycated protein to produce a glycated peptide product (E), on which fructosyl amino acid oxidase (FAOD) enzyme (B) does not substantially act; iii) producing a glycated amino acid product (C) by adding to the reaction mixture a protease enzyme (F) that is different from the protease enzyme (A) to act on the glycated peptide product (E); and iv) detecting the glycated amino acid product (C) in the reaction mixture with the fructosyl amino acid oxidase (FAOD) enzyme (B), peroxidase (POD) and a color-developing reagent to produce a detectable color.