Toyo Boseki Kabushiki Kaisha

Toyo Boseki Kaubshiki Kaisha

Shizuo Hattori

Yoshihisa Kawamura

Shigenori Emi

Yukihiro Sogabe

Kazumi Yamamoto

Shinichi Teshima

Takahide Kishimoto

Atsushi Sogabe

Noriyuki Hongo

Masanori Oka

Seiji Takeshima

Yoshihiro Yamamoto

The present invention provides a stable lyophilized PQQ-dependent glucose dehydrogenase composition comprising a PQQ-dependent glucose dehydrogenase together with (i) at least one compound selected from the group consisting of aspartic acid, glutamic acid, &#x3b1;-ketoglutaric acid, malic acid, &#x3b1;-ketogluconic acid, &#x3b1;-cyclodextrin and their salts and (ii) an albumin.

Stable PQQ-dependent glucose dehydrogenase composition

The present invention provides novel glutathione-dependent formaldehyde dehydrogenase that makes possible quantitative measurement of formaldehyde by cycling reaction, and a determination method of formaldehyde and biological components, such as creatinine, creatine, and homocysteine, which produces formaldehyde as a reaction intermediate. In addition, the present invention provides a reagent kit for the above-mentioned determination method. The present invention provides a novel determination method of a homocysteine using transferase utilizing homocysteine and other compound as a pair of substrates. Particularly, the present invention provides a determination method of homocysteine which includes bringing betaine-homocysteine methyltransferase and dimethylglycine oxidase into contact with a sample and measuring produced hydrogen peroxide or formaldehyde. Moreover, the present invention provides novel dimethylglycine oxidase stable to thiol compound, which is suitably used for the measurement. The present invention provides a reagent kit used for any of the above-mentioned determination methods of homocysteine.

Determination method of biological component and reagent kit used therefor

A novel glutamate dehydrogenase derived from the genus Pseudomonas which is specific to L-glutamic acid, requires NAD.sup.+ and NADH as coenzymes, does not act on NADP.sup.+ and NADPH, is with an optimum pH 10.5-11.5 (oxidative deamination), a pH stability of 5-10 (at 25.degree. C.; 20 hours), an optimum temperature of about 60.degree. C. (oxidative deamination) and a molecular weight of about 280,000 (gel filtration) or about 41,000 (SDS-PAGE) and is not activated by ADP. A reagent composition for measuring an amount of ammonia characterized in containing a glutamate dehydrogenase which is not activated by ADP and is NADH-dependent, .alpha.-ketoglutaric acid or a salt thereof and NADH; and a reagent composition wherein urease or creatinine deiminase is further added to the above-mentioned reagent composition.

Reagent composition of glutamate dehydrogenase from pseudomonas

A novel alkaline phosphatase and a method for the production of the alkaline phosphatase are described. A method for detecting a ligand in a sample and a method for analyzing the sequence of nucleic acid in a sample using the alkaline phosphatase are also described.

Alkaline phosphatase

Method and reagent for detecting a ligand in a sample

A novel glutamate dehydrogenase is derived from the genus Pseudomonas and is specific to L-glutamic acid, requires NAD.sup.+ and NADH as coenzymes, does not act on NADP.sup.+ and NADPH, has an optimum pH 10.5-11.5 (oxidative deamination), a pH stability of 5-10 (at 25.degree. C.; 20 hours), an optimum temperature of about 60.degree. C. (oxidative deamination) and a molecular weight of about 280,000 (gel filtration) or about 41,000 (SDS-PAGE) and is not activated by ADP.

Glutamate dehydrogenase from Pseudomonas

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 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.

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Tsuruga, Japan

Shizuo Hattori