Abstract: A novel method for quantifying a 25-hydroxyvitamin D concentration, a hydroxylase, a quantification composition, a quantification kit, an electrode, a sensor chip, and a sensor are provided. A method for quantifying 25-hydroxyvitamin D by adding a mediator and hydroxylase to a sample can be provided. Quantification of an oxidized mediator produced by an action of the hydroxylase, or oxygen or a reduced mediator consumed by an action of the hydroxylase may be included.

Abstract: The present invention provides a protein having pentosidine oxidase activity, a method for measuring pentosidine comprising: contacting the protein with a specimen; and detecting a change caused by the contact, and the like.

Abstract: There is provided a novel quantification method for quantifying a concentration of EAP, which is a biomarker of depression, an enzyme for quantitation, a composition for quantitation, a kit for quantitation or a sensor for quantitation. There is provided a quantification method of ethanolamine phosphate by adding oxidoreductase to a sample containing ethanolamine phosphate. A mediator may be reduced by adding the oxidoreductase, and the reduced mediator may be reacted with a reagent to determine a concentration of ethanolamine phosphate. In addition, hydrogen peroxide produced by adding the oxidase as the oxidoreductase may be reacted with a reagent to determine a concentration of the ethanolamine phosphate.

Abstract: An object of the present invention is to provide a device for evaluating a state of interstitial fluid, blood, urine, tears, sweat, saliva of human and non-human organisms, foods and drinks, brewed product, etc., a system, a program, and an evaluation method using these. The present invention is to provide a device for evaluating a state of a sample which comprises an action part for allowing lactate dehydrogenase to act on a sample, and a sensor for sensing the state of the sample on which lactate dehydrogenase is allowed to act, a system, a program, a method for evaluating the state of the sample using these, and an enzyme to be used therefor.

Abstract: A quantitation method of ethanolamine phosphate capable of measuring trace amounts of ethanolamine phosphate, or oxidoreductase used for the quantitation method thereof, a quantitation composition, a quantitation kit, a sensor chip, or a sensor is provided. According to an embodiment of the present invention, a quantitation method of ethanolamine phosphate including allowing phosphatase to act on a sample to convert ethanolamine phosphate contained in the sample into ethanolamine, and allowing oxidoreductase to act on the ethanolamine is provided.

Abstract: Provided is a composition by which glycated hemoglobin can be measured even in the presence of a stronger surfactant than a conventional case. Also provided is a buffer and/or stabilizer which maintains the residual activity of an amadoriase or lowers a reduction of residual activity. The present invention provides a composition for use in measuring glycated hemoglobin containing an amadoriase having substitution of one or more amino acid residues at a position(s) corresponding to an amino acid(s) selected from the group consisting of position 262, position 257, position 249, position 253, position 337, position 340, position 232, position 129, position 132, position 133, position 44, position 256, position 231 and position 81 of an amadoriase derived from the genus Coniochaeta and represented by SEQ ID No: 1 or 3, and having residual activity even in the presence of a surfactant.

Abstract: Provided is a method for measuring pentosidine in a specimen, the measurement method comprising the steps of: degrading the specimen with an amino acid degrading enzyme; contacting the specimen after the degradation step with a protein having activity that oxidatively degrades pentosidine; and detecting change resulting from the contact, wherein the amino acid degrading enzyme and the protein having activity that oxidatively degrades pentosidine are different from each other.

Abstract: Provided are an amadoriase that is less likely to be influenced by oxygen concentration and a method and a reagent kit for measurement of HbA1c using such amadoriase. Provided are an amadoriase that is obtained via substitution of one or more amino acid residues at a position or positions corresponding to the position(s) selected from the group consisting of positions 280, 267, 269, 54, and 241 of the amadoriase derived from the genus Coniochaeta, a method for measurement of HbA1c, a reagent kit for measurement, and a sensor using such amadoriase. The modified amadoriase according to the invention has a lowered oxidase activity and an enhanced dehydrogenase activity, and this enables the use of an electron mediator, and this reduces the influence of oxygen concentration. Thus, HbA1c can be measured with high sensitivity.

Abstract: A quantitation method of vitamin D derivative is provided including adding an oxidoreductase to a sample. The quantitation method of vitamin D derivative may further include reducing a mediator by adding the oxidoreductase, and reacting the reduced mediator with a reagent to determine a concentration of the vitamin D derivative.

Abstract: Provided is a compound which accelerates the enzymatic reaction catalyzed by an oxidase. The present invention provides an oxidase reaction accelerating agent comprising a compound represented by formula (I) and a method using the same.

Abstract: A new quantification method for measuring citrulline, which has an association with various diseases and is a biomarker particularly useful for early diagnosis of rheumatoid arthritis, an enzyme for quantification, a composition for quantification, and a kit for quantification are provided. A quantification method of citrulline is provided by adding a citrulline oxidoreductase to a sample. The oxidoreductase is an oxidase, and a concentration of the citrulline may be determined by quantifying hydrogen peroxide produced by addition of the oxidase. A concentration of the citrulline may be determined by reacting a reagent with hydrogen peroxide produced by addition of the oxidase.

Abstract: In one embodiment, an object of the present invention is to provide a firefly luciferase having improved thermostability. In one embodiment, the present invention relates to a luciferase mutant having improved thermostability that is a mutant of firefly luciferase comprising an amino acid sequence in which the amino acid residue at the position corresponding to position 393 of SEQ ID NO 1 is substituted, a polynucleotide encoding the luciferase mutant, and a production method of the luciferase mutant.

Abstract: Provided is a compound capable of accelerating the enzymatic reaction catalyzed by peroxidase. The present invention provides a peroxidase reaction accelerating agent comprising a compound represented by formula (I) and a method for measuring hydrogen peroxide using the same.

Abstract: There is provided a novel quantification method for quantifying a concentration of EAP, which is a biomarker of depression, an enzyme for quantitation, a composition for quantitation, a kit for quantitation or a sensor for quantitation. There is provided a quantification method of ethanolamine phosphate by adding oxidoreductase to a sample containing ethanolamine phosphate. A mediator may be reduced by adding the oxidoreductase, and the reduced mediator may be reacted with a reagent to determine a concentration of ethanolamine phosphate. In addition, hydrogen peroxide produced by adding the oxidase as the oxidoreductase may be reacted with a reagent to determine a concentration of the ethanolamine phosphate.

Abstract: This invention provides an HbA1c dehydrogenase that is capable of directly acting on hemoglobin A1c and is less likely to be influenced by oxygen concentration and a method for measurement and a kit of assay reagents using such HbA1c dehydrogenase. The HbA1c dehydrogenase having dehydrogenase activity and capable of directly acting on HbA1c is obtained by substitution of one or more amino acid residues at positions corresponding to positions 280, 269, 54, 241, and 267 of the amadoriase that is capable of directly acting on hemoglobin A1c and is derived from, for example, the genus Coniochaeta. This invention also provides a method for measurement of HbA1c, a kit of assay reagents, and a sensor using such HbA1c dehydrogenase. Such HbA1c dehydrogenase is capable of directly acting on hemoglobin A1c and has lowered oxidase activity and/or enhanced dehydrogenase activity.

Abstract: This invention provides an amadoriase that acts on the ?-chain of hemoglobin A1c (HbA1c) and generates hydrogen peroxide, a method for measurement of HbA1c using such amadoriase, and a reagent kit for measurement of HbA1c using such amadoriase. The method for measurement of HbA1c involves the use of an amadoriase that has specific activity of 0.1 U/mg or greater to ?F6P and oxidizes the HbA1c ?-chain amino terminus so as to generate hydrogen peroxide, and the reagent kit for measurement of HbA1c comprises such amadoriase. The method and the kit for measurement of HbA1c enable quantification of HbA1c to be performed rapidly, simply, and accurately.

Abstract: In one embodiment, an object of the present invention is to provide a firefly luciferase having improved thermostability. In one embodiment, the present invention relates to a luciferase mutant having improved thermostability that is a mutant of firefly luciferase comprising an amino acid sequence in which the amino acid residue at the position corresponding to position 393 of SEQ ID NO 1 is substituted, a polynucleotide encoding the luciferase mutant, and a production method of the luciferase mutant.

Abstract: This invention provides an amadoriase having improved specific activity on a glycated substrate, compared with conventional amadoriase. Provided is an amadoriase comprising a substitution of the amino acid at the position corresponding to position 64 of the amino acid sequence as shown in SEQ ID NO: 1 with an amino acid selected from the group consisting of glycine, serine, methionine, leucine, threonine, valine, and isoleucine, a method for measurement of HbA1c, and a reagent kit for measurement of HbA1c using such amadoriase. Such method and kit for measurement enable rapid, simple, and accurate quantification of HbA1c.

Abstract: The present invention provides a protein having pentosidine oxidase activity, a method for measuring pentosidine comprising: contacting the protein with a specimen; and detecting a change caused by the contact, and the like.

Abstract: Provided is a glycated hemoglobin oxidase with small measurement error or without deviation of the measured value from the true value regarding a sample containing glycated abnormal hemoglobin. Provided are a glycated hemoglobin oxidase comprising an amino acid sequence in which the amino acid at the position corresponding to position 113, 109, 106, or 102 of the amino acid sequence of SEQ ID NO: 1 is substituted with an amino acid other than a positively-charged amino acid, such as glutamic acid, alanine, or aspartic acid as well as a method and a reagent kit for measurement of glycated hemoglobin using such glycated hemoglobin oxidase. The glycated hemoglobin is capable of reacting with various genotypes and enables highly accurate measurement of glycated hemoglobin in a sample containing glycated abnormal hemoglobin.