Kikkoman Corporation

Eriko Yoshihara

Kozo Hirokawa

Ryoko Tajima

Atsushi Ichiyanagi

Keisuke Furukawa

Kazuhiko Shimoji

Yasuko Tanabe

Yukako Kodama

To reduce the effect of L-proline in the reaction of a sarcosine oxidase. A modified sarcosine oxidase having reduced reactivity to L-proline is provided.

Modified sarcosine oxidase, and gene and production method therefor

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.

[object Object]

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 Heike firefly luciferase having excellent thermostability and storage stability and a process for its production, wherein the amino acid corresponding to position 287 of Heike firefly luciferase is alanine.

Growing community of inventors

Noda, Japan

Eriko Yoshihara