Toyo Boseki Kabushiki Kaisha

Toyo Boseki Kaubshiki Kaisha

Yukihiro Sogabe

Shigenori Emi

Shizuo Hattori

Atsushi Sogabe

Yoshiaki Nishiya

Takahide Kishimoto

Kazumi Yamamoto

Yukio Takii

Yuzuru Suzuki

Kayoko Furukawa

Michiyo Minami

Yoshihiro Yamamoto

Naoko Tanigaki

A protein having an .alpha.-glucosidase activity, wherein its N-terminal amino acid sequence is the sequence depicted in the Sequence Listing of the present invention at Sequence No. 1; a DNA having the genetic information of the protein having an .alpha.-glucosidase activity; a recombinant vector containing said DNA; a transformant transformed with said vector; and production of .alpha.-glucosidase comprising culture of said transformant in a medium so as to grow .alpha.-glucosidase, and harvesting said .alpha.-glucosidase. According to the present invention, .alpha.-glucosidase without contamination of amylase can be easily produced in high yields and in large amounts by genetic engineering.

Protein having .alpha.-glucosidase activity, DNA having genetic

The sorbitol oxidase of the present invention catalyzes the reaction in which D-sorbitol is oxidized D-glucose and hydrogen peroxide.

Sorbitol oxidase reagent from xanthomonas

A method for measuring carbon dioxide, comprising the steps of: (1) reacting bicarbonate ion in a sample with phosphoenolpyruvate carboxylase derived from an acetic acid bacterium in the presence of phosphoenolpyruvate; (2) reacting the resultant oxalacetic acid with malate dehydrogenase in the presence of NADH; and (3) measuring decreased NADH, and a reagent for measuring carbon dioxide, comprising phosphoenolpyruvate, phosphoenolpyruvate carboxylase derived from an acetic acid bacterium, malate dehydrogenase, NADH and a buffer. According to the present invention, a highly stable reagent for CO.sub.2 measurement, which permits a long-term storage in a liquid state, can be provided by the use of phosphoenolpyruvate carboxylase derived from a species of acetic acid bacteria.

Method for measuring carbon dioxide and reagent therefor

A method for determining .alpha.-amylase activity which involves bringing a sample into contact with an .alpha.-glucosidase in the presence of an .alpha.-amylase substrate and optically determining a liberated label, the substrate being a maltooligosaccharide composed of at least 3 glucose units, whose reducing terminal glucose is bonded to an optically measurable label at the 1-position by .alpha.-glucoside linkage or .beta.-glucoside linkage, and whose non-reducing terminal glucose is modified by a substituent other than glucose, and the .alpha.-glucosidase being substantially capable of acting on glucose to which the label is bonded at the 1-position by .alpha.-glucoside linkage and on all maltooligosaccharides having 2 to 7 glucose units; and a reagent for determining .alpha.-amylase activity comprising the .alpha.-glucosidase and said .alpha.-amylase substrate. The present invention permits, in the determination of .alpha.-amylase activity, efficient auxiliary action of adjuvant enzyme, a determination with good sensitivity, and little reagent blank reaction.

Method for determination of .alpha.-amylase activity

A protein having an .alpha.-glucosidase activity, wherein its N-terminal amino acid sequence is the sequence depicted in the Sequence Listing of the present invention at Sequence No: 1; a DNA having the genetic information of the protein having an .alpha.-glucosidase activity; a recombinant vector containing said DNA; a transformant transformed with said vector; and production of .alpha.-glucosidase comprising culture of said transformant in a medium so as to grow .alpha.-glucosidase, and harvesting said .alpha.-glucosidase. According to the present invention, .alpha.-glucosidase without contamination of amylase can be easily produced in high yields and in large amounts by genetic engineering.

DNA encoding .alpha.-glucosidase and method of producing same by genetic

A method for measuring carbon dioxide, comprising the steps of: (1) reacting bicarbonate ion in a sample with phosphoenolpyruvate carboxylase derived from an acetic acid bacterium in the presence of phosphoenolpyruvate; (2) reacting the resultant oxalacetic acid with malate dehydrogenase in the presence of NADH; and (3) measuring decreased NADH, and a reagent for measuring carbon dioxide, comprising phosphoenolpyruvate, phosphoenolpyruvate carboxylase derived from an acetic acid bacterium, malate dehydrogenase, NADH and a buffer. According to the present invention, a highly stable reagent for CO.sub.2 measurement, permitting a long-term storage in a liquid state can be provided by the use of phosphoenolpyruvate carboxylase derived from an acetic acid bacterium.

An isolated sorbitol oxidase from Xanthomonas maltophilia FERM BP-4512 is disclosed. The oxidase catalyzes the reaction of D-sorbitol+O.sub.2 .fwdarw.D-glucose+H.sub.2 O.sub.2, has a substrate specificity for D-sorbitol, D-mannitol, D-xylitol, and D-arabitol, has an optimum pH of 6.5 to 7.5, and has a molecular weight of 54 kD as determined by gel filtration or 43 kD as determined by SDS-PAGE. The enzyme can be used for measuring a polyol in a sample and as a reagent in a kit used for determining the presence of D-sorbitol.

Sorbitol oxidase from Xanthomonas maltophilia FERM BP-4512

A substantially purified glucose dehydrogenase is disclosed. The enzyme has activity at a temperature of from about 30.degree. C. to about 65.degree. C. at a pH of from about pH 6 to about pH 10 and has an optimum activity at a temperature from about 50.degree. C. to about 60.degree. C. at a pH of from about 8.5 to about 9.0. The enzyme is further characterized by retaining at least 90% residual activity after treatment at 50.degree. C. for 15 minutes, being NAD or NADP dependent, having a molecular weight of about 101,000 daltons as determined by gel filtration using TSK gel, having an isoelectric point of about 4.5 by ampholyte isoelectric focusing, and having a specificity for at least .beta.-D-glucose and 2-deoxyglucose. The preferred source of the enzyme is Pseudomonas sp. FH1227.

Glucose dehydrogenase from pseudomonas

A new thermostable xanthine oxidase obtained from a microbe belonging to the genus Arthrobacter and a method of its production are disclosed. The present invention affords a xanthine oxidase which is excellent in thermal stability and which retains at least 70% residual activity after heat treatment at 60.degree. C. for 30 minutes. Arthrobacter luteus ATCC 21606 is the preferred microbe. The enzyme has a molecular weight of about 160,000 daltons as determined by gel filtration and a pH optimum of about 7.5.

Growing community of inventors

Tsuruga, Japan

Yukihiro Sogabe