1044 results about "Transaminase" patented technology

The invention discloses a method for preparing L-glufosinate-ammonium by use of amino acid dehydrogenase. The method comprises the following steps: taking 2-carbonyl-4-(hydroxymethylphosphonyl)butyric acid or a salt thereof as a substrate, taking a cell of the isolated glutamate dehydrogenase or in vitro expression glutamate dehydrogenase as a catalyst to perform reductive amination reaction under the condition of the existence of inorganic amino donor and reduced coenzyme, thereby acquiring the L-glufosinate-ammonium. The method disclosed by the invention is high in raw material conversion rate and high in yield, the product is easy to separate and purify, and the chirality purity is high; compared with the transaminase and like catalysis technology, the process is relatively simple, and the raw material conversion rate reaches up to 100%.

The invention discloses a production method of L-glufosinate. The method includes the steps that with 2-carbonyl-4-(hydroxyl methyl phosphoryl) butyric acid and salt thereof being a substrate, isolated transaminase or a cell catalysis substrate of in-vitro expression transaminase reacts with an amino donor under the condition that the amino donor exists, so that L-glufosinate is obtained, wherein the amino donor is alanine, and the amino acid sequence of transaminase is shown in SEQ ID NO.1-3. With 2-carbonyl-4-(hydroxyl methyl phosphoryl) butyric acid and salt thereof being the substrate and alanine being the amino donor, the transamination reaction occurs through the specific transaminase catalysis substrate, the substrate can be completely converted into L-glufosinate, and the conversion rate of raw materials is high and can reach 100%.

Relating to an enzyme capable of efficiently converting a ketone compound to an optically active amino compound by transamination, and a process for preparing an optically active amino compound using the enzyme. An (S)-alpha-phenethylamine:pyruvate transaminase, which acts on (S)-alpha-phenethylamine and a ketone compound, thereby catalyzing transamination for forming acetophenone and an amino compound corresponding to the ketone compound; a process for preparing an optically active amino compound using the transaminase; and a method for culturing a microorganism for producing the above transaminase, comprising adding to a medium one or more compounds selected from the group consisting of propylamine, 1-butylamine, 2-butylamine, 2-pentylamine, isopropylamine and isobutylamine as an inducer for the enzyme when a microorganism for producing (S)-alpha-phenethylamine:pyruvate transaminase is cultured.

The invention provides a method for improving fermentability and nutritional property of gluten protein-free dough. The method includes the steps of 1) activating glutamic acid transaminase, protease A and yeast; 2) peptizing food in water with temperature 50-100 degrees to be evenly mixed with whole flour free of gluten protein, proteins, starches, sugars and salts; 3) adding the activated glutamic acid transaminase and protease A to the mixture for evenly mixing; 4) adding and stirring the activated yeast in the mixture to form the dough; 5) fermenting the mixture within 40-90mins at the temperature of 36-40 degrees and at the humidity of 70-85%. The method is simple and greatly improves the nutritional property and the fermentability of the gluten protein-free dough at the same time. Thus fermentation size of the dough is increased by 1-3 times, contents of vitamin, protein, dietary fiber, mineral elements and the like are remarkably increased, structures and sizes of fermented products such as breads, steamed breads and steamed sponge cakes are improved, and nutritional value of the fermented products is increased.

The invention discloses a saccharomyces cerevisiae strain with high yield of ester and low yield of higher alcohol as well as a building method of the saccharomyces cerevisiae strain, and belongs to the technical field of bioengineering. According to the building method provided by the invention, through completely knocking out an amino acid transaminase gene BAT2 and an ester hydrolase gene IAH1 in an original strain, and selecting a strong promoter PGK1 over-expression alcohol acetyltransferase I gene ATF1 at the same time, the saccharomyces cerevisiae strain with high yield of ester and low yield of higher alcohol is obtained. Compared with a parent strain, other fermentation performances of built recombinant bacteria are not affected, the total quantity of acetic acid ester is obviously increased and reaches 1303.6mg/L, wherein the content of ethyl acetate is 52 times that of the original strain, isoamyl acetate is increased to 73.7mg/L, the content of main higher alcohol is 151.8mg/L and is reduced by 61.4 percent in comparison with that of the original strain. By using the saccharomyces cerevisiae, ester yield is significantly increased while the higher alcohol yield is reduced, the higher requirements of white spirit related fields on yeast are met and the application prospect is wide.

The invention provides a transaminase mutant and applications of the transaminase mutant. The amino acid sequence of the transaminase mutant is the amino acid sequence with mutation as shown in SEQ IDNO:1, the amino acid sites with mutation comprise the T7C+S47C site. For the transaminase mutant with the mutation sites, the enzyme activity and/or stability are/is greatly improved, and the transaminase mutant can be applied in the relatively extreme environment. In addition, the transaminase mutant with the mutation sites can be further prepared into immobilized enzyme through the immobilization technology, the activity and the stability of the immobilized enzyme are relatively high, and the immobilized enzyme can be recycled for a plurality of times, and is suitable for being applied to continuous flow reaction of a packed bed.

To provide a method for preparing optically active compounds, which mainly contain (R)-amino compounds, by microbial enzymes efficiently and inexpensively; a polypeptide having stereoselective transaminase activity which can be suitably used for the above preparation method; and a DNA encoding the polypeptide. A method for preparing an optically active amino compound, characterized in stereoselectively transaminating by acting a transaminase on an amino group acceptor, a ketone compound in the presence of an amino group donor, a primary amine; a DNA comprising a nucleotide sequence encoding a polypeptide having stereoselective transaminase activity; and a polypeptide having stereoselective transaminase activity obtainable from a culture of a microorganism belonging to the genus Arthrobacter.

The invention discloses a transaminase mutant and application thereof. The amino acid sequence of the transaminase mutant is formed after mutation of an amino acid sequence as shown in SEQ ID No. 1, and a mutant amino acid site is one or more selected from a group consisting of F89, K193, P243, V234, I262, Q280, V379, R416, A417 and C418. The transaminase mutant with at least one mutant amino acidsite selected from the above group is greatly improved in enzymatic activity and/or stability.

The invention discloses an omega-aminotransferase mutant gene and an application thereof, and belongs to the field of the molecular biological technology. The nucleotide sequence of the omega-aminotransferase mutant gene is shown as SEQ ID NO.1. The omega-aminotransferase amino acid sequence embodied by the code of the omega-aminotransferase mutant gene is shown as SEQ ID NO.2. The omega-aminotransferase mutant gene is firstly provided, and the omega- aminotransferase corresponding to the code of the omega-aminotransferase mutant gene has a high enzyme amount, so that the biological catalysis and conversion efficiency is improved in industrial production. The invention further provides the application of the omega-aminotransferase embodied by the code of the omega-aminotransferase mutant gene in preparation of trifluoro-propylamine. The trifluoro-propylamine is added to a buffer solution to serve as the substrate for the reaction, and then products of trifluoromethyl amine compounds are collected from the reaction liquid. The method for preparing the trifluoro-propylamine has the obvious advantages that the reaction conditions are mild, no pollution is caused, and the process is simple.

A preparation method of soybean protein isolate transparent hydrogel with high gel strength and a high swelling property is provided, comprising: using defatted soybean meal as a raw material, preparing high-purity soybean protein isolate by alkali extraction and acid precipitation; ultrasonic pretreatment, performing ultrasonic treatment on a soybean protein isolate dispersion liquid with concentration of 5% (w/v) for 30 to 90 min; preparing a protein/polysaccharide aggregate solution, mixing chitosan with the soybean protein isolate subjected to the ultrasonic treatment in a mass ratio of 2-7%, performing heat treatment at temperature of 95 DEG C for 30 min, and then cooling to room temperature; adding a glutamine transaminase to the foregoing thermal aggregate solution in a mass ratio of 4-8% (enzyme/protein, m/m); eliminating air bubbles by centrifugation; performing incubation at temperature of 55 DEG C for 4 h; performing enzyme deactivation by heating in water bath at temperature of 95 DEG C for 10 min; performing ice-bath cooling; and placing the mixture in a refrigerator of 4 DEG C for 24 h. The invention is added to food production as a substitute for food additives, and improves an additional value and quality of soybean food, thereby implementing low-carbon sustainable production.

The invention establishes aminopherase through genetic engineering. Compared with ochrobactrum anthropi based wild w-aminopherase coming from ochrobactrum anthropi, the enzyme activity of aminopherase is remarkably improved, and aminopherase can be used for industrially producing L-2-aminobutyric acid.

The present invention relates generally to the field of molecular biology and concerns a method for enhancing various economically important yield-related traits in plants. More specifically, the present invention concerns a method for enhancing yield-related traits in plants by modulating expression in a plant of a nucleic acid encoding an ASPAT (Asparatate AminoTransferase) polypeptide. The present invention also concerns plants having modulated expression of a nucleic acid encoding an ASPAT polypeptide, which plants have enhanced yield-related traits relative to control plants. The invention also provides hitherto unknown ASPAT-encoding nucleic acids and constructs comprising the same, useful in performing the methods of the invention. Furthermore, the present invention relates generally to the field of molecular biology and concerns a method for increasing various plant yield-related traits by increasing expression in a plant of a nucleic acid sequence encoding a MYB91 like transcription factor (MYB91 ) polypeptide. The present invention also concerns plants having increased expression of a nucleic acid sequence encoding an MYB91 polypeptide, which plants have increased yield- related traits relative to control plants. The invention additionally relates to nucleic acid sequences, nucleic acid constructs, vectors and plants containing said nucleic acid sequences. Even furthermore, the present invention relates generally to the field of molecular biology and concerns a method for improving various plant growth characteristics by modulating expression in a plant of a nucleic acid encoding a GASA (Gibberellic Acid-Stimulated Arabidopsis). The present invention also concerns plants having modulated expression of a nucleic acid encoding a GASA, which plants have improved growth characteristics relative to corresponding wild type plants or other control plants. The invention also provides constructs useful in the methods of the invention. Yet furthermore, the present invention relates generally to the field of molecular biology and concerns a method for enhancing various economically important yield-related traits in plants. More specifically, the present invention concerns a method for enhancing yield-related traits in plants by modulating expression in a plant of a nucleic acid encoding an AUX/IAA (auxin/indoleacetic acid) polypeptide. The present invention also concerns plants having modulated expression of a nucleic acid encoding IAA polypeptide, which plants have enhanced yield-related traits relative to control plants. The invention also provides constructs comprising AUX/IAA-encoding nucleic acids, useful in performing the methods of the invention.

The invention discloses lactobacillus plantarum which was collected in China General Microbiological Culture Collection Center on 25th, Sep., 2013. The collection number is CGMCC No.8242, and the collection address is No. 3, 1 Beichen West road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences. The lactobacillus plantarum provided by the invention has high activities of peptidase and aminotransferase. When the lactobacillus plantarum used as an auxiliary leavening agent is added into a cheddar cheese model, contents of water-soluble nitrogen, 5% PTA-SN and 12% TCA-SN in cheese are higher, protein decomposition degree can be improved effectively, flavoring characteristics of aged cheddar cheese can be formed in a short period of time, sensory scores of nut and sulphur taste of the aged cheese in the cheddar cheese model are increased, ripening period of cheddar cheese is shortened and the cost of storage can be saved.

The invention provides immobilized transaminase. The immobilized transaminase is obtained by fixing transaminase, with histidine tag, derived from Mycobacterium vanbaalenii PYR-1 onto an enzyme immobilization carrier; the enzyme immobilization carrier is obtained by derivatization of epoxy resin through IDA (imino diethyl acetic acid) and cobalt chloride or derivatization of ionic chelate resin through cobalt chloride. The immobilized transaminase has the advantages of firmness in combination, low enzyme activity loss, simplicity in separation and high reusability; low cost of an asymmetric conversion process, mild reaction conditions, environment friendliness, simplicity and convenience in operation, easiness in industrial expanding and promising industrial application prospect are realized.

The invention discloses a transaminase mutant and application thereof. An amino acid sequence of the transaminase mutant is an amino acid sequence obtained by mutation of an amino acid sequence shownin SEQ ID NO:1, and mutation at least comprises one of the following mutation site combinations: T7C+S47C, Q78C+A330C, V137C+G313C, A217C+Y252C and L295C+C328C; or the amino acid sequence of the transaminase mutant is an amino acid sequence which has a mutation site in a mutant amino acid sequence and has 80% homology or above with the mutant amino acid sequence. The transaminase mutant realizes change of protein structure and functions, reduces enzyme dose, increased the ee value of the product and reduces after treatment difficulty, so that the transaminase mutant can be suitable for industrial production.

The invention discloses transaminase derived from actinomyces, a mutant, recombinant bacteria and application. A biological preparation method of R-3-aminobutanol, provided by the invention, takes butanone alcohol as a raw material the price is cheap. A large amount of needed recombinant transaminase can be prepared through constructing escherichia coli genetic engineering bacteria and then fermenting, and is relatively easy to obtain and cheap. Reaction is one-pot-boiling type reaction; after a substrate and an enzyme are added, the reaction is started and a final product R-3-aminobutanol isdirectly obtained; the industrial cost is low. Compared with a wild type, an actinomyces transaminase mutant provided by the invention has better catalytic activity. Under an optimal system, the conversion rate on the 100mM substrate reach 90 percent and the ee value reaches 99.9 percent; the conversion rate on the 500mM substrate reach 78 percent and the ee value reaches 99.9 percent; compared with the wild type, the actinomyces transaminase mutant has the advantage that the conversion rates on the substrates are respectively improved by 12 percent to 25 percent.

The invention discloses a medicine with anti-inflammatory, anti-hepatitis, anti-tumour and organism immunity improving functions and preparation method thereof, solving the technical problems of improving curative effect of treatment on hepatitis and tumour diseases. The medicine of the invention comprises the following traditional Chinese medicine materials by weight proportion: 800-1200g of sculellaria barbata, 400-600g of dedyotis diffusa and 400-600g of Chinese lobelia. The preparation method thereof includes: the raw materials crude slices are decocted and concentrated, ethyl alcohol is added and standing at room temperature is carried out, filtering is carried out, pH is adjusted to be 8.0, filtrate is recovered until no ethyl alcohol is remained, then ethyl alcohol is added for standing, filtrate is recovered until no ethyl alcohol is remained, pH value is adjusted to be 7.5, and filtration is carried out. Compared with the prior art, the invention has the advantages that sculellaria barbata, dedyotis diffusa and Chinese lobelia have the efficacies of clearing heat and detoxicating, eliminating blood stasis for analgesic and inducing diuresis for reducing edema, combination of the three not only can realize anti-inflammatory, anti-hepatitis, anti-tumour functions but also can improve organism immunity, liver and spleen can be obviously shrunk for hepatitis patients, and transaminase and other liver function indexes can be improved in an all-round way.

The invention discloses transaminase, a mutant and application thereof in production of L-glufosinate ammonium. The mutant is characterized in that isoleucine at the 62nd site of amino acid in SEQ IDNO:2 is substituted by valine; serine at the 74th site is substituted by threonine; methionine at the 93rd site is substituted by isoleucine; tyrosine at the 167th site is substituted by phenylalanine; alanine at the 220th site is substituted by proline; arginine at the 282nd site is substituted by lysine; alanine at the 353rd site is substituted by serine; isoleucine at the 355th site is substituted by valine. The transaminase is characterized in that 4-(methyl hydroxyphosphoryl)-2-carbonyl-butyric acid is used as a primer to prepare the L-glufosinate ammonium, the transaminase product ee isgreater than 99.9%; the 4h primer conversion rate is 56.31%; the transaminase mutant product ee is greater than 99.9%, and the 4h primer conversion rate is 95.42%.

Provided is an omega-transaminase mutant with improved activity using a point mutation in an active site of an omega-transaminase. Specifically, provided is a method for improving activity and extending a substrate spectrum of omega-transaminase by introducing a point mutation into a wild-type omega-transaminase rendered by replacing tryptophan at position 58 with the other amino acid.