Abstract: The present invention relates to a method for purifying target protein which contains electron transfer protein, from a protein solution containing the target protein, by means of liquid chromatography. The liquid chromatography is performed as follows: First, the protein solution is introduced into a column which is filled with a packing agent, thereby causing the packing agent to bond to the target protein. Then, impurities are removed, and then the target protein is eluted from the packing agent in an eluent which contains a hydroxy-cholate. An example of the target protein is glucose dehydrogenase which contains a protein having glucose dehydrogenation activity. The liquid chromatography is performed as a combination of hydrophobic chromatography and anion exchange chromatography.

Abstract: The present invention relates to a method for purifying target protein which contains electron transfer protein, from a protein solution containing the target protein, by means of liquid chromatography. The liquid chromatography is performed as follows: First, the protein solution is introduced into a column which is filled with a packing agent, thereby causing the packing agent to bond to the target protein. Then, impurities are removed, and then the target protein is eluted from the packing agent in an eluent which contains a hydroxy-cholate. An example of the target protein is glucose dehydrogenase which contains a protein having glucose dehydrogenation activity. The liquid chromatography is performed as a combination of hydrophobic chromatography and anion exchange chromatography.

Abstract: A process for producing glucose dehydrogenases. This process comprises transferring a DNA containing a sequence represented by SEQ ID NO:1 which encodes an ? subunit having a glucose dehydrogenase activity and a ? subunit being an electron transfer protein into a microorganism belonging to the genus Pseudomonas to thereby construct a transformant, and culturing this transformant so as to allow the production of a first glucose dehydrogenase containing the above-described ? subunit and a second glucose dehydrogenase free from the ? subunit. The ? subunit as described above has a molecular weight of about 60 kDa measured by, for example, SDS-polyacrylamide gel electrophoresis under reducing conditions, while the ? subunit as described above has a molecular weight of about 43 kDa measured by, for example, SDS-polyacrylamide gel electrophoresis under reducing conditions.

Abstract: A glucose dehydrogenase complex is produced by culturing an Escherichia bacterium, which is introduced with DNAs encoding the ?-subunit and the ?-subunit of glucose dehydrogenase of Burkhorderia cepacia in an expressible form, and in which expression of the ccm system (cytochrome c maturation system) is enhanced, to express the aforementioned DNAs and produce a glucose dehydrogenase complex, and collecting the complex.

Abstract: A method of purifying a target protein from a solution, in which the target protein containing an electron transfer protein is dissolved, with the use of liquid chromatography. The liquid chromatography is performed by introducing the above-described protein solution into a tank filled with a packing agent, thus bonding the target protein to the packing agent, removing impurities, and then eluting the target protein from the packing agent with the use of an eluent containing a hydroxycholanoic acid salt. As an example of the above protein, glucose dehydrogenase containing a protein having an activity of dehydrogenating glucose is cited. The liquid chromatography is performed by combining hydrophobic chromatography with anion exchange chromatography.

Abstract: A gene encoding thermostable glucokinase, a recombinant vector comprising this gene, a transformant transformed with the recombinant vector, and a process for producing thermostable glucokinase with the use of the transformant.

Abstract: A novel sorbitol dehydrogenase having excellent substrate affinity and substrate specificity which can be used to measure D-sorbitol which occurs in human erythrocytes and serum in a slight amount or D-sorbitol or D-fructose contained in foods, a microorganism for producing such an enzyme, and a process for the production of the enzyme using such a microorganism. Also disclosed is provides a method for the measurement of sorbitol using the foregoing sorbitol dehydrogenase and a reagent for the quantitative determination therefor.

Abstract: A gene encoding thermostable glucokinase, a recombinant vector comprising this gene, a transformant transformed with the recombinant vector, and a process for producing thermostable glucokinase with the use of the transformant.

Abstract: A reagent system and method are described for optically measuring direct bilirubin by the reaction of a bilirubin oxidase, oxidizing agent or diazonium salt, with the direct bilirubin, wherein a tetrapyrrole compound is provided in the presence of the bilirubin oxidase, oxidizing agent or diazonium salt. It is possible to accurately measure the direct bilirubin, which is known to increase considerably in the biological fluids of patients having obstructive jaundice, etc. The reagent system and method are useful in clinical settings, etc.