Abstract: The invention relates to an ammonia elimination reagent for use in an enzymatic assay of a biological substance which produces ammonia as the reaction product. The reagent is an alkaline solution of pH 9 to 11 and contains Sulfolobus-derived thermostable isocitrate dehydrogenase, 2-oxoglutaric acid, a reducing coenzyme, isocitric acid, glutamate dehydrogenase, and a divalent metal salt. The reagent can be stored in solution and has excellent stability under conditions of alkaline pHs.

Abstract: The present invention relates to a .beta.AP decomposing agent or a medicine for preventing and curing Alzheimer's disease, which contains, as the active ingredient, gelatinase A, a limited decomposate of gelatinase A, progelatinase A, a complex to which any of them has bonded or a material containing any of them. .beta.AP is a substance which is considered to cause Alzheimer's disease.

Abstract: The present invention provides a gene encoding the type B subunit protein of avian lactate dehydrogenase. The gene encoding the type B subunit protein of avian lactate dehydrogenase of the present invention is obtained by plaque hybridization or the like from a cDNA library derived from avian heart muscle and encodes the type B subunit protein of avian lactate dehydrogenase having the sequences shown as SEQ ID NO. 1 or 2.

Abstract: GMT is produced by E. coli transformant with an expression vector having introduced therein cDNA of glycine-N-methyl transferase (GMT) derived from rat liver. This process can produce GMT of a high purity and a high activity on an industrial scale.

Abstract: A packing paper for baker's yeast, which is constituted by laminating, on one side of a base paper, at least a printing layer and a wax layer in this order and which has a carbon dioxide permeability of 400-2,000 cm.sup.3 /m.sup.2 .multidot.24 h.multidot.atm., an oxygen permeability of 100-600 cm.sup.3 /m.sup.2 .multidot.24 h.multidot.atm. and a moisture permeability of 50 g/m.sup.2 .multidot.24 h or less.

Abstract: A sample is treated with a phosphoglyceric acid mutase (PGAM) inhibitor (polythionic acid (salt) such as potassium tetrathionate) to inactivate the M-type isozyme activity and the B-type PGAM is quantified by determining PGAM isozymes by a rate assay. The B-type PGAM is a novel marker for cerebral apoplexy, and the diagnosis of cerebral apoplexy is enabled by assaying it.

Abstract: An accurate and effective measurement of copper in subject samples is rendered possible even for minute amounts of copper, by converting copper-bonded hologalactose oxidase to the apo-form by liberation of the copper, and measuring the copper of the sample in a reaction system containing the apogalactose oxidase.

Abstract: Calcium in a sample is brought into contact with a transglutaminase capable of being activated with calcium as an activating factor and the transglutaminase activity, which varies depending upon the calcium amount in the sample, is measured to thereby determine the calcium amount in the sample. By the method of the invention, accurate determination of calcium in various samples such as body fluids is possible without removal of proteins from them.

Abstract: The present invention relates to immunoglobulin-binding artificial proteins (repetitively linked-proteins) which result when either one of or several numbers of the IgG-binding domains in protein A molecule is defined as a unit, and repetitive multiple links are made thereof. These repetitive proteins exhibit a superior ability for IgG purification to naturally occurring protein A, and the mixture of these repetitive proteins may be used as excellent molecular weight markers.

Abstract: The present invention relates to a gelatinase A inhibitor comprising as an active ingredient a peptide analogue consisting of an active minimum unit of gelatinase A inhibition obtained from APP (.beta.-amyloid precursor) or a peptide analogue comprising it. Gelatinase A can be qualified and quantified using any of the gelatinase A inhibitors according to the present invention.

Abstract: This invention relates to an enzyme assay for quantitative analysis of biochemical substances using NAD(P)-NAD(P)H system and utilizing hydrogen peroxide, in which isocitric acid, metal ions and isocitrate dehydrogenase are previously added to a test sample, thereby consuming the endogenous substances that interfere the analysis, and at the same time regenerating NAD(P)H reduced.The isocitrate dehydrogenase is then inactivated by addition of a chelating agent, an enzyme or substrate that generates hydrogen peroxide as reaction product is added simultaneously or thereafter, and the amount of hydrogen peroxide thus formed is measured.Biochemical substances that generate hydrogen peroxide as reaction product can be correctly analyzed by this method with no adverse effect of endogenous substances because these interfering substances have been removed prior to measurement.

Abstract: The present invention measures serum iron by liberating iron from transferrin under acid conditions, and contacting a test sample with a reaction system which utilizes at least aconitase, a reducing reagent, citric acid, isocitrate dehydrogenase and (thio)NAD(P). According to the present invention, an accurate and efficient measurement of iron in the serum is possible, even for minute levels of iron. In addition, the present invention assays unsaturated iron binding capacity by adding excess iron to a test sample to bind iron to transferrin, binding the remaining unbound iron to aconitase, and measuring the activated aconitase. According to the present invention, a quick and easy assay of unsaturated iron binding capacity of body fluids, etc. is possible without the need for expert skill.

Abstract: Urea, creatinine, creatine, triglycerides, or the like in a specimen can be accurately determined by terminating an isocitrate dehydrogenase reaction by addition of a chelating agent in a system wherein NADP.sup.+ formed from NADPH is reproduced into NADPH in the conjoint presence of an isocitrate, metallic ions such as magnesium or manganese ions, and isocitrate dehydrogenase in assaying a substance by means of a reaction of NADPH to NADP.sup.+.

Abstract: The present invention relates to a process for producing yeast extract which comprises adding chitosan to yeast thereby to accelerate autolysis. Organic solvents have been added in the past. However, organic solvents are frequently not naturally occurring substances in the concentrations used. When yeast extract is used for food, there are problems with toxicity, flavor, etc. should organic solvents not be completely removed. Accordingly the present invention prepares an excellent yeast extract using chitosan derived from natural substances thereby to accelerate autolysis of yeast without the unwanted problems of organic solvents.

Abstract: A new method of rapidly analyzing plural substances in the presence of biological catalyzers is disclosed. The method is practiced by way of the steps of injecting both pH buffer solution and specimen into a reaction cell, successively adding a plurality of enzymes to induce up-take reaction of dissolved oxygen, causing the plurality of substances to be subjected to selective oxidation in the stepwise manner, obtaining a stepdown curve of dissolved oxygen by automatically recording the oxidative process by means of a dissolved oxygen sensor, qualitatively determining each of the substances with reference to the kind of added enzymes and the order of their addition and quantitatively determining the same with reference to the extent of decrease in dissolved oxygen. Typically, oxidation of the substances is carried out by way of two or three or further more steps.

Abstract: The plasmid of the present invention contains Leu 2 gene (.beta.-isopropylmaleate dehydrogenase gene) from Saccharomycopsis lipolytica and an autonomously replicating sequence (hereafter referred to as ARS) and can be a shuttle vector between Escherichia coli and Saccharomycopsis lipolytica since it is produced from shuttle vector pVC 1 of Escherichia coli and Saccharomyces cerevisiae. An exogenous useful gene is inserted into the plasmid of the present invention, namely, shuttle vector to transform Escherichia coli, whereby a large quantity of plasmids are obtained. It becomes possible to produce a useful substance in Saccharomycopsis lipolytica as a host using the plasmid.

Abstract: Disclosed is a method of assaying the content of Mg ions in a human body fluid such as serum, urine or saliva by the use of a reactant solution containing isocitrate dehydrogenase, NADP.sup.+, isocitrate and an excess amount of a chelating agent. Almost all Mg ions as existing in a human body fluid sample to be examined are bonded with the chelating agent, and the remaining Mg ions react with NADP.sup.+ to form NADPH. Increase of the thus formed NADPH is measured to obtain a standard curve of a straight line, and the content of Mg ions in the same is determined on the basis of the standard curve. If such an excess amount of a Mg-chelating agent is not added to the reactant solution, the intended standard could not be in the form of a straight line but is in the form of a tangent curve. Using the tangent curve, the content of Mg ions in the human body fluid sample cannot be assayed accurately.

Abstract: This invention relates to a method of diagnosing cancerous diseases, which comprises measuring the amount of UDP-N-acetylglucosamine:glycoprotein N-acetylglucosaminyl-transferase in body fluid and evaluating the increase in its amount for the diagnosis of hepatic diseases.AFP, CEA and .gamma.-glutamyltranspeptidase have hitherto been used as tumor markers for the diagnosis of hepatic cancer. But these conventional tumor markers show a positivity rate of about 60%, making early diagnosis almost impossible.The method of this invention employs UDP-N-acetylglucosamine:glycoprotein N-acetylglucosaminyltransferase as tumor marker, whereby early diagnosis of hepatic cancer can be made almost completely.

Abstract: New .alpha.-amylase inhibitor from wheat (WAI-53). The inhibitor is characterized especially by having molecular weight of 24,000 as determined by gel filtration, giving a single band at an electrophoretic mobility of 0.53 on polyacrylamide gel electrophoresis according to the Davis Disc Electrophoresis Method and producing saturation curves of WAI-53 with human salivary alpha-amylase and with human pancreatic alpha-amylase with a ratio of the amount of WAI-53 required to produce 50% inhibition of human salivary .alpha.-amylase to that of human pancreatic amylase above 1:250. The alpha-amylase inhibitor is used for quantitative analysis of alpha-amylase isozymes in body fluid.

Abstract: Urea, creatinine, creatine, triglycerides, or the like in a specimen can be accurately determined by terminating an isocitrate dehydrogenase reaction by addition of ATP and/or a chelating agent in a system wherein NAD.sup.+ formed from NADH is reproduced into NADH in the conjoint presence of an isocitrate, metallic ions such as magnesium or manganese ions, and isocitrate dehydrogenase in assaying a substance by means of a reaction of NADH to NAD.sup.+.