103 results about "Malate dehydrogenase" patented technology

The invention provides a gene engineering bacterial strain for producing L-malic acid as well as a construction method and application thereof. In the invention, key phosphoenolpyruvate carboxykinase(PEPCK) related to the L-malic acid, malate dehydrogenase (MDH) and fumarase (FumC) are transformed to obtain the gene engineering bacterial strain; a deactivation mutation is carried out on the fumCto cause the interruption of a metabolic flux at the converting position from the malic acid to the fumaric acid so as to accumulate the target product L-malic acid; before the mdh, the promoter of aninner source pepck gene is added to generate the metabolic flux biased towards the malic acid; in addition, through the inducement of monofluorine sodium acetate, the activity of the PEPCK is improved, and the product feedback inhibition is greatly reduced. The bacterial strain applied to the fermentative production of the L-malic acid so as to obviously improve the yield of L-malic acid. The invention has advantages of simple technology, obvious effect and low cost and can satisfy the demand of markets.

The invention discloses a plane expression vector for increasing the ability of resisting the aluminum toxicity and the application thereof, which belongs to plant genetic engineering field. The vector contains the Escherichia coli malate dehydrogenase (EMDH); the upstream of the malate dehydrogenase (EMDH) is Rubisco small subunit photoinduced promoter. The test shows that, the activity of EMDH of transgene tobacco obtained by transforming the tobacco by the vector is 1 to 3.3 times of that of the wild tobacco. Under the stress of 100 to 300uM aluminum toxicity, the EMDH transferred tobacco can secrete more malic acid; the root grows well, which has an enhanced tolerance for aluminum toxicity. The specific vector of the invention can increases the tolerance for aluminum toxicity of the plant, and has a great potential of application in improving the crops in particular in the acid soil of South China.

The invention discloses a nucleotide analogue and a synthesis and a application thereof. The constitutional formula of the nucleotide analogue is that: Tetra-O-Acetyl-D-Ribose is adopted as a raw material and generates the nucleotide analogue containing a triazole ring formwork through four steps of reaction, wherein R is C2-C15 saturated or unsaturated alkyl, or C2-C10 saturated or unsaturated alkyl containing hetero atoms; or R is R1 which is hydroxyl, alkoxy, amino or substituent amido; or R is R2 which is aryl or saturated or unsaturated alkyl; or R is R3 which is halogen, amono, methoxyl, methyl or other substituent. The nucleotide analogue can restrain the growth of microorganism such as escherichia coli, and can be used as an inhibitor of dehydrogenase such as malate dehydrogenase.

The invention discloses a kit for determining mitochondria aspartate aminotransferase, containing a reagent 1 and a reagent 2, wherein the reagent 1 contains aspartic acid protease, alpha- ketoglutaric acid, L-aspartic acid, malate dehydrogenase, lactate dehydrogenase, a preservative and PEG6000. The enzyme activity ratio of the aspartic acid protease to the malate dehydrogenase to the lactate dehydrogenase in the reagent 1 is (0.1-50):(0.1-50):(0.1-10); the ratio of the alpha- ketoglutaric acid to the malate dehydrogenase is (0.1-60)g:(0.1-50)KU; the mass ratio of the alpha- ketoglutaric acid to the L-aspartic acid to the preservative to the PEG6000 is (0.1-60):(5-200):(0.2-10):(1-100); and the mass ratio of NADH (Reduced Form of Nicotinamide-Adenine Dinucleotid) to a preservative to EDTA (Ethylene Diamine Tetraacetic Acid).2Na is (0.5-10):(0.2-10):(1-50). The kit for determining the mitochondria aspartate aminotransferase is used for determining the activity of the determining mitochondria aspartate aminotransferase, is free from the interference of high cell plasma aspartate aminotransferase and obtains accurate result.

The invention provides a genetically engineered bacterium for producing malic acid efficiently by means of xylose fermentation and a construction method and application of the genetically engineered bacterium. In the recombinant bacterium, hosphopentose isomerase, L-fuculokinase, L-fucose-1-phosphate aldolase, aldehyde dehydrogenase, glycolate oxidase and malate synthase are overexpressed, and meanwhile xylulokinase, malate dehydrogenase and fumarate hydratase are knocked out, so that a malic acid synthesis route is obtained. According to the recombinant bacterium, the malic acid yield and the xylose conversion rate in shake flask culture and fermentation tank culture can reach ideal levels, and a good industrialized application prospect is achieved.

The present invention finds the protective effect of the hydrophilic domain on the enzyme in the Dhp(DR1172) protein. The present invention expresses a core protein containing a complete hydrophilic domain. The experimental results showed that the protein was repeatedly frozen and thawed in liquid nitrogen and H ₂ O ₂ Both can protect the activities of malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) under shock stress conditions, and both can reduce the aggregation of LDH and prevent its structure from changing to protect its activity.

The invention discloses saccharomyces cerevisiae gene engineering bacteria for producing succinic acid and application thereof, and belongs to the fields of genetic engineering and fermentation engineering. Malate dehydrogenase gene RoMDH from rhizopus oryzae is adopted to replace PDC1, the yield of ethanol obtained by fermentation of wild saccharomyces cerevisiae reaches the maximum value 13.55 plus or minus 1.062g/L, and the yield of improved strain MP ethanol is 11.09 plus or minus 0.539g/L, and compared with the yield obtained by adopting the wild type, the yield is reduced by 18.15 percent. On the basis, SDH2 gene is knocked out. After culture medium optimization, MP Delta S deleted strain can accumulate succinic acid by 0.698 plus or minus 0.0285g/L, and by contrast, the wild saccharomyces cerevisiae does not accumulate succinic acid. The saccharomyces cerevisiae gene engineering bacteria can effectively reduce the loss of a carbon flow, creates a condition for the engineering yeast to efficiently produce succinic acid, and has a good industrial application value and prospect.

The invention relates to the technical field of biochemical detection, in particular to a detection kit for aspartate aminotransferase with good repeatability and a preparation and application methodthereof. The kit comprises a reagent R1 and a reagent R2. The reagent R1 comprises a buffer solution, a PH value adjusting agent, L-aspartic acid, potassium ferrocyanide, an AP5A, an EGTA, lithium chloride, a surfactant, levoglucosides, lactate dehydrogenase, malate dehydrogenase, and a preservative component. The reagent R2 comprises a buffer solution, a PH value adjusting agent, a BSA, a preservative, a-ketoglutarate, and NADH components. The kit is optimized in terms of removing reflection interference, increasing the activity of the reacted enzyme, improving the uniformity of the reactionsystem, and preferably selecting the excellent sub-wavelength. The kit remarkably improves the repeatability of reagents, especially the repeatability of low-value samples so as to improve the accuracy of clinical diagnosis results and achieve great clinical practical value.

The invention provides a stable reagent for determining glutamic oxalacetic transaminase. The reagent is a dual reagent and comprises TRIS (tris (hydroxymethyl) aminomethane), NADH (reduced form of nicotinamide-adenine dinucleotid), LDH (lactate dehydrogenase), MDH (malate dehydrogenase), EDTA (ethylene diamine tetraacetic acid), TritonX-100, BSA (bovine serum albumin) and Proclin. According to the reagent, the heat stability, onboard stability and transportation stability of an in-vitro diagnosis reagent of an NADH indicating system are effectively improved; and the shelf life of a reagent kit can be prolonged effectively.

The present invention relates to a method to calculate oxalate decarboxylase activity by detecting carbon dioxide concentration, which comprises 1) mixing substrate, oxalate decarboxylase, and HAC buffer at a temperature between of 30-37 degree C for 0.5 to 1 hour; 2) confecting Tris-HCl buffer at pH values between 7.3-8.5 containing phosphate enol type pyruvate, phosphoenolpyruvate carboxylase, NADH, malate dehydrogenase at a temperature between of 30-37 degree C, after incubation, detecting A1 at 380 nm location; 3) adding the reaction solution of step 1) into the solution of step 2), reacting at a temperature between of 30-37 degree C and detecting A2 at 380 nm location; 4) calculating NADH decrement according to the formula of delta A380nm=A1-A2, and calculating the generated carbon dioxide consistence according to the reaction principles to calculate oxalate decarboxylase activity. The said method is a good method for dectecting oxalate decarboxylase which is credibility, high sensitivity, and the valve detected thereby is close to the value detected by the classical method for detecting oxalate decarboxylase.

The invention discloses a tea tree cytoplasmic malate dehydrogenase gene and an encoding protein thereof, wherein the enzyme has an amino acid sequence shown by SEQ ID NO: 1. Compared with the prior art, the malate dehydrogenase containing a Cam-cyMDH gene can be widely used for separating D, L-malic acid and be applied to the tea tree F1 hybrid.

The invention discloses a synthesis method of 3[alpha],7[beta]-dihydroxy-5[alpha]-cholanic acid. The method takes allochenodeoxycholic acid as an initial raw material and includes the following steps: adding phosphate buffer, nicotinamide adenine dinucleotide phosphate, lactate dehydrogenase, 7-[alpha]hydroxysteroid dehydrogenase and sodium pyruvate, performing reaction, and performing cooling after enzyme was inactivated through high temperature; additionally adding L-sodium malate, malate dehydrogenase and 7-[beta]hydroxysteroid dehydrogenase to react, and performing cooling to room temperature after the enzyme was inactivated through high temperature; and obtaining the 3[alpha],7[beta]-dihydroxy-5[alpha]-cholanic acid through filtration, washing and drying. The overall process of the method includes the oxidation and reduction steps of the allochenodeoxycholic acid and the synthesis of the 3[alpha],7[beta]-dihydroxy-5[alpha]-cholanic acid. The whole reaction of the method is conducted in an aqueous solution without using organic solvents; the method is simple in technology and easy to operate; and the purity of the obtained 3[alpha],7[beta]-dihydroxy-5[alpha]-cholanic acid can reach more than 98.5%, and the obtained 3[alpha],7[beta]-dihydroxy-5[alpha]-cholanic acid can be used as samples of pharmaceutical properties such as toxicology and pharmacology in pharmaceutical research institutions and can also be used as impurity reference substances during quality research of ursodeoxycholic acid.

The invention relates to a method for performing secretory expression of glucose oxidase (GOD) based on the optimization of metabolic engineering, a recombinant bacterium and application thereof. The invention provides a method which can efficiently secretorily express GOD and improve the enzyme activity thereof. The GOD and malic acid dehydrogenase 1 coding gene (mdh1) or 6-phosphogluconolactonase coding gene (sol3) is co-expressed in a yeast strain, so that the efficient expression of the GOD is realized. Meanwhile, the invention also provides a recombinant bacterium for efficiently secreting the GOD built by adopting pichia pastoris as a host.

The invention relates to methods for the treatment of tumors and/or for immune suppression and/or sepsis by modulating the association of the glycolysis enzyme complex/M2-PK and/or by inhibition of transaminases and/or separation of the binding of the malate dehydrogenase to p36 comprising administering a pharmaceutical composition comprising a substance selected from the group consisting of amino acids, amino acid analogs, sugar phosphates, sugar phosphate analogs, and mixtures of said substances.