THERMOSTABLE 1,5-ANHYDROGLUCITOL DEHYDROGENASE, AND METHOD FOR MEASUREMENT OF 1,5-ANHYDROGLUCITOL BY USING THE SAME

摘要

The protein (1) or (2) shown below can act specifically on 1,5-anhydroglucitol (1,5-AG), and has thermal stability and therefore exhibits excellent storage stability. Thus, the protein is an extremely useful enzyme for the commercialization of a quantification reagent or an enzyme sensor for 1,5-AG to achieve the convenient and practical 1,5-AG measurement. (1) A protein comprising an amino acid sequence having at least one mutation selected from a Gly-4 to Ala mutation, a Glu-6 to His mutation, a Ser-14 to Thr mutation, an Ala-3 7 to Thr or Arg mutation, a Pro-50 to Gln mutation, a Glu-67 to Gly mutation, an Asp-80 to Tyr mutation, a Val-93 to Met mutation, an Arg-156 to Pro mutation, a Leu-164 to Met mutation, an Asn-202 to Asp mutation, a Thr-235 to Ala mutation, an Asn-348 to Tyr mutation, a Gly-362 to Arg mutation and a Val-473 to Ala mutation in the amino acid sequence depicted in SEQ II NO:4. (2) A thermostable protein which comprises an amino acid sequence having the addition, deletion or substitution of one to several amino acid residues other than the mutated amino acid residue(s) in the amino acid sequence having at least one mutation as mentioned in item (1) above, and which has an 1,5-anhydroglucitol dehydrogenase activity.