Nippon Kayaku Kabushiki Kaisha

Ikeda Food Research Co., Ltd.

Shuhei Tsukamoto

Minoru Masuda

Hideki Yoshioka

Hironori Omura

Hirokazu Sanada

Emi Ishimaru

Masahiko Yabuuchi

Yoshihiko Umegae

Reiko Machida

The object of the present invention is to provide a method of determining 1,5-anhydroglucitol, including using (a) a protein which consists of the amino acid sequence of SEQ ID NO: 2; (b) a protein which consists of an amino acid sequence having deletion, substitution and/or addition of one or more amino acid residues in the amino acid sequence of SEQ ID NO: 2 and which has sorbose dehydrogenase activity; or (c) a protein which consists of an amino acid sequence having a homology of at least 60% with the amino acid sequence of SEQ ID NO: 2 and which has sorbose dehydrogenase activity.

Method of determining 1,5-anhydroglucitol, and reagent composition for determining 1,5-anhydroglucitol

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-37 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 derived from the amino acid sequence having at least one variation described in (1) and having 1,5-anhydroglucitol dehydrogenase activity. These proteins act specifically on 1,5-anhydroglucitol (1,5-AG), have thermal stability and exhibit excellent storage stability.

Thermostable 1,5-anhydroglucitol dehydrogenase, and method for measurement of 1,5-anhydroglucitol by using the same

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Takasaki, Japan

Shuhei Tsukamoto