Patent ID: 7091017

Claim:
An isolated fructosyl amino acid oxidase having the following physicochemical properties: (a) action and substrate specificity: catalyzing a reaction to generate glyoxylic acid or α-ketoaldehyde, an α-amino acid and hydrogen peroxide by oxidizing iminodiacetic acid, or a derivative thereof, in the presence of oxygen, but not acting on ε-fructosyl lysine; (b) optimum pH range: 7.5 to 8.5; (c) stable pH range: 5.0 to 10.0; (d) optimum temperature range for action: 40° C. to 50° C.; (e) thermal stability: showing 80% or more remaining activity when heat treatment is performed for 10 minutes at 50° C.; and (f) molecular weight: approximately 88,000 (determined by gel filteration), and approximately 44,000 (determined by SDS-PAGE).