| abstract |
Provided is an amadoriase which has high reactivity with an α-fructosyl hexapeptide (αF6P) originated from the β-chain amino terminal of glycated hemoglobin (HbA1c) and enables the satisfactory quantification of an αF6P that has been cleaved from HbA1c. A novel amadoriase produced by substituting at least one amino acid residue at a position corresponding to an amino acid residue selected from the group consisting of amino acid residues located at position-62, position-63, position-102, position-106, position-110, position-113, position-355 and position-419 in an amadoriase originated from a bacterium belonging to the genus Coniochaeta . The amadoriase enables the rapid, simple, highly accurate and satisfactory quantification of an αF6P that has been cleaved from HbA1c. Using the amadoriase, it is possible to provide: an HbA1c measurement method by an enzymatic method, which is based on the same principle as that in a conventional reference method and is superior with respect to the correlation with a reference method; and an HbA1c measurement kit. |