A reagent measuring a glycated protein, comprising a protease and a protein of any one of [1] to [4] below:[1] a protein comprising the amino acid sequence represented by SEQ ID NO:1[2] a protein comprising an amino acid sequence with one to ten amino acid deletions, substitutions, or additions in the amino acid sequence represented by SEQ ID NO:1, and having fructosyl peptide oxidase activity[3] a protein comprising an amino acid sequence having 99% or higher homology to the amino acid sequence represented by SEQ ID NO:1, and having fructosyl peptide oxidase activity and[4] a protein having fructosyl peptide oxidase activity, which is encoded by an expression plasmid harbored by the Escherichia coli XL1-Blue MRF′ strain deposited under Accession No. FERM BP-11026.
