Kikkoman Corporation

Ryoko Tajima

Atsushi Ichiyanagi

Kozo Hirokawa

Eriko Yoshihara

Keiichi Ichikawa

Yasuko Tanabe

Masanobu Yuzuki

Taro Yoshimura

A heat-resistant flavin-bound glucose dehydrogenase having a high substrate specificity for D-glucose, an method for producing the same, and a transformant used for the same. A flavin-bound glucose dehydrogenase gene encoding a flavin-bound glucose dehydrogenase derived fromis introduced into yeast,, to obtain a transformant. Subsequently, the yeast transformant is cultured to obtain a flavin-bound glucose dehydrogenase from the culture. The heat-resistant flavin-bound glucose dehydrogenase is less susceptible to the effects of dissolved oxygen and allows accurate measurement of glucose even in the presence of sugar compounds other than glucose in a sample.

Flavin-bound glucose dehydrogenases, a method for producing a flavin-bound glucose dehydrogenase, and yeast transformant used for the same

A flavin-bound glucose dehydrogenase (FAD-GDH) with high substrate specificity for D-glucose. A gene encoding a mutant FAD-GDH with its N-terminal region, containing an amino acid sequence corresponding to MKITAAIITVATAFASFASA that exists in the N-terminal region, deleted from the amino acid sequence of a wild-type FAD-GDH derived fromis introduced intoto obtain antransformant. Subsequently, thistransformant is cultured to obtain an FAD-GDH with a specific N-terminal region deleted. The transformant allows the production of a large amount of GDH in a short time as compared with the original microorganism. An FAD-GDH that is less susceptible to the effects of dissolved oxygen and allows accurate measurement of glucose even in the presence of sugar compounds other than glucose in a sample.

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A flavin-binding glucose dehydrogenase (FAD-GDH), which in addition to having high substrate specificity and adequate desirable heat stability, is suitable for efficient production, preferably using, yeast or molds and the like as host cells. The FAD-GDH has amino acid substitutions at positions equivalent to one or more locations selected from the group consisting of position 213, position 368 and position 526 in the amino acid sequence described in SEQ ID NO: 8. The FAD-GDH is acquired from a culture by inserting a gene encoding the FAD-GDH into host cells such as. A preferable example of the FAD-GDH is FAD-GDH, in which a signal peptide region present in an N-terminal region has been deleted from the amino acid sequence of Mucor-derived FAD-GDH, and which has the aforementioned amino acid substitutions. The FAD-GDH can be preferably used in clinical diagnosis.

Flavin-binding glucose dehydrogenase, method for producing flavin-binding glucose dehydrogenase, and glucose measurement method

A flavin-binding glucose dehydrogenase with a high substrate specificity for D-glucose. The flavin-binding glucose dehydrogenase which is derived from a microorganism belonging to the genus. The flavin-binding glucose dehydrogenase has a low reactivity for maltose, D-galactose and D-xylose compared to its reactivity for D-glucose, and therefore is relatively unaffected by these saccharide compounds. The flavin-binding glucose dehydrogenase is also relatively unaffected by dissolved oxygen, and allows accurate measurement of glucose amounts even in the presence of saccharide compounds other than glucose in samples.

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Noda, Japan

Ryoko Tajima