2059 results about "Enzyme catalysis" patented technology

An improved biosensor having at least a first working electrode and a first electrode material disposed on the first working electrode. The first electrode material is a mixture made by combining at least one enzyme where the at least one enzyme is a capable of reacting with the analyte to be measured, a redox mediator capable of reacting with a product of an enzymatic reaction or a series of enzymatic reactions involving the at least one enzyme, a peroxidase capable of catalyzing a reaction involving the redox mediator where the redox mediator is oxidized, a binder and a surfactant.

The present invention relates a graphene/metal oxide hybrid aerogel, a preparation method and applications thereof, and belongs to the field of nanometer material applications. The hybrid aerogel comprises a graphene network and a metal oxide network, wherein the two networks are mutually wound to form a hybrid aerogel, and the metal oxide network is further a crystalline state. The hybrid aerogel preparation comprises: preparing a graphene oxide organic solution, adding a soluble metal salt and an epoxide to obtain a uniform non-flowing hybrid wet gel, and carrying out drying and charring to obtain the graphene/metal oxide hybrid aerogel. The hybrid aerogel can be used as an energy storage material, an electromagnetic shielding material, a biological enzyme catalysis carrier and a CO2 absorption material, and has wide applications.

The invention discloses a biomacromolecule interpenetrating polymer network hydrogel and a preparation method of the biomacromolecule interpenetrating polymer network hydrogel. The biomacromolecule interpenetrating polymer network hydrogel is formed by crosslinking two kinds of enzymes in a catalysis mode, one is a polysaccharide macromolecule network formed by crosslinking polysaccharide macromolecules with introduced phenolic hydroxyl groups in an oxidation mode as oxidase and hydrogen peroxide catalyze phenolic hydroxyl groups, and the other is a protein or polypeptide macromolecule network formed crosslinking protein or polypeptide containing amino acid residues as transferase catalyzes peptide bonds. The two networks interpenetrate each other and form the novel interpenetrating polymer network hydrogel without bonding of chemical bonds. No chemical crosslinking agent is used in the hydrogel, and the hydrogel has excellent biocompatibility and mechanical property, can be shaped like a dry or wet film, like porous sponge or fibers, and can serve as a contact lens, a medicine release carrier, a scaffold for tissue engineering or materials for tissue repair.

The invention discloses a bio-macromolecular hydrogel prepared by enzyme catalysis and ion cross-linking, and a preparation method of the bio-macromolecular hydrogel. The bio-macromolecular hydrogel comprises a protein or polypeptide bio-macromolecular network formed by enzyme-catalyzed cross-linking of protein or polypeptide or amino acid residue-containing molecule, accounting for 1-99 wt% of total dry mass of the hydrogel; and a polysaccharide bio-macromolecular network formed by bivalent ion cross-linking of polysaccharide macromolecule, accounting for 1-99 wt% of total dry mass of the hydrogel. The above two networks are inter-penetrated without chemical bonding. The hydrogel has the advantages of excellent mechanical properties, no use of chemical cross-linking agent, simple and effective preparation method, good bio-compatibility and mechanical strength, and capability of steam sterilization; may be in the forms of wet or dry film, porous sponge, tube and particles; and can be used in cell/tissue culture, and used as tissue repair material, tissue engineered scaffold or drug release carrier.

The invention discloses a method for producing L-2-aminobutyric acid, and the method comprises the following step: catalyzing L-threonine utilized as a raw material through an enzyme catalysis system consisting of threonine deaminase, L-amino acid dehydrogenase and coenzyme regeneration systems, thus producing the L-2-aminobutyric acid. The method for producing theL-2-aminobutyric acid has the advantages that the raw material is low in price, the property is stable, and the production cost of the L-2-aminobutyric acid can be greatly lowered, the conversion rate and product concentricity are high, no influence caused by byproducts exists, and the method is suitable for industrialization application.

A bio-enzyme consists of pectinase, protease, lipase, cellulose, catalase and amylase; the application of bio-enzyme catalysis in residual sludge treatment is that: the residual sludge is treated by utilizing the high-efficiency biocatalysis of the bio-enzyme, odor molecules in the sludge are decomposed and deodorized through enzyme technology, pathogenic bacteria, ova and larvae are killed by utilizing an acid environment formed by inorganic acid generated by the sludge and a high temperature environment in the fermentation process, heavy metal ions in the sludge are stabilized by utilizing the chelation of the bio-enzyme, and the sludge is catalyzed by the enzyme, so that the sludge and water are quickly separated, a large amount of supernate is discharged, the sludge volume is reduced, and the sludge in inland river is reduced and is subjected to innocent treatment; meanwhile, through the bio-enzyme catalysis, long-chain molecules in the sludge are converted into short-chain molecules, polysaccharide and cellulose are converted into protein and amino acid, nutritional components of organic fertilizers are remained, the fertilizer efficiency is improved and the fermentation period can be shortened.

The subject invention relates to the identification of a gene involved in the elongation of polyunsaturated fatty acids containing unsaturation at the carbon 9 position (i.e., “Δ9-elongase”) and to uses thereof. In particular, Δ9-elongase may be utilized, for example, in the conversion of linoleic acid (LA, 18:2n-6) to eicosadienoic acid (EDA, 20:2n-6). The production of dihomo-γ-linolenic acid (DGLA, 20:3n-6) from eicosadienoic acid (EDA, 20:2n-6), and arachidonic acid (AA, 20:4n-6) from dihomo-γ-linolenic acid (DGLA, 20:3n-6) is then catalyzed by Δ8-desaturase and Δ5-desaturase, respectively. AA or polyunsaturated fatty acids produced therefrom may be added to pharmaceutical compositions, nutritional compositions, animal feeds, as well as other products such as cosmetics.

Cell lines having genetically modified glycosylation pathways that allow them to carry out a sequence of enzymatic reactions, which mimic the processing of glycoproteins in humans, have been developed. Recombinant proteins expressed in these engineered hosts yield glycoproteins more similar, if not substantially identical, to their human counterparts. The lower eukaryotes, which ordinarily produce high-mannose containing N-glycans, including unicellular and multicellular fungi are modified to produce N-glycans such as Man₅GlcNAc₂ or other structures along human glycosylation pathways. This is achieved using a combination of engineering and/or selection of strains which: do not express certain enzymes which create the undesirable complex structures characteristic of the fungal glycoproteins, which express exogenous enzymes selected either to have optimal activity under the conditions present in the fungi where activity is desired, or which are targeted to an organelle where optimal activity is achieved, and combinations thereof wherein the genetically engineered eukaryote expresses multiple exogenous enzymes required to produce “human-like” glycoproteins.

The invention discloses a method for regenerating ATP by enzymatic method, which comprises the following steps: (1) preparing and obtaining ATP regenerating enzyme; (2) regenerating ATP in reaction liquid; (3) separating products and ATP regenerating enzyme. According to the method for regenerating ATP of the present invention, it has the following beneficial effects: (1) adopt three kinds of ATP regenerating enzymes of novel Ppk, Adk and Pap, the ATP consumed in the enzymatic reaction can be recycled and regenerated, greatly reducing the amount of ATP used, regenerated The process is simple and efficient, the reaction is easy to control, and the stability is high. (2) The substrate polyphosphoric acid or its salt to be added to the reaction is cheap and less polluting. (3) The enzymatic reaction does not need to add expensive ATP to start the reaction, add ADP or cheap AMP. (4) ATP regenerating enzyme recovery system was established, which is suitable for large-scale industrial production.

The invention discloses an enzyme catalysis graft function finishing method of wool, comprising the steps of pretreatment, enzyme catalysis graft function finishing, hot water termination reaction, water-washing for 10 times, then drying at the temperature of 60 to 80 DEG C and the like. The method adopts transglutaminase catalytic functional primary amine to graft and finish the wool, thus improving the performances of antiflaming, antibiosis, uvioresistance, skin-friendly and easy nursing and the like of the wool. The additional value of the wool is added; and the enzyme catalysis function finishing method has good durability, is environment friendly, and has strong operability, lower processing temperature, and no influence to the whiteness and other performances of the wool, thus being an energy-saving, environment-friendly and clean wool after-finishing technology.

The invention discloses a preparation method of a human milk substitute fat based on a triglyceride composition and an evaluating method of the human milk substitute fat. The preparation method comprises the following steps: with lard oil as a base raw material, adding sunflower seed oil, canola oil, palm kernel oil, palm oil, microbial oil and algae oil in the lard oil according to a certain proportion in accordance with composition and distribution of fatty acid of human milk fat to obtain mixed oil similar to the human milk fat on the composition and distribution of the fatty acid; and by adopting specific lipase at 1 and 3 sites as catalysts, and similarities between of mixed oil and human milk fat in aspects of composition and distribution of the fatty acid, composition of polyunsaturated fatty acids and triglyceride as indexes, adjusting the composition of the triglyceride of the mixed fat by using a manner of lactone exchanging to obtain a product with relatively high similarity to the human milk fat on the composition of the triglyceride. The human milk substitute fat is obtained by adopting physical mixing and enzyme catalysis ester exchange manners, the production cost can be greatly reduced, and the relatively high similarity is achieved for the product and the human milk fat.

The invention relates to a preparation method of a hydrogel rapidly crosslinked by enzyme catalysis, and application thereof. A precursor of the hydrogel consists of a mixture (hereinafter referred to as No. 1 solution) of good-biocompatibility macromonomer aqueous solution with an active phenolic hydroxyl unit and dioxygenase aqueous solution which is taken as a catalyst, and the aqueous solution of the precursor can rapidly react to form a 3D polymer cross-linked network after an oxidant (usually low-concentration oxydol, hereinafter referred to as No. 2 solution) is injected. As the No. 1 solution and the No. 2 solution have low-viscosity characteristic, are suitable for being transported and injected, and can rapidly crosslink to form a gel network, the hydrogel can be used for vascular embolization treatment, cancer treatment, family planning operation blocking agents, injectable tissue engineering scaffold materials, soft tissue fillers of human body, controlled release drug carriers, anti-adhesive membranes used in operations and the like after adding one or a plurality of components with specific properties to the No. 1 solution or the No. 2 solution or the gel network.

The invention discloses a method for preparing L-phosphinothricin through deracemization and by a biological enzyme method. According to the method, the L-phosphinothricin is obtained by taking D,L-phosphinothricin as a raw material and through catalysis by an enzyme catalysis system, and the enzyme catalysis system consists of D-amino acid oxidase, amino acid dehydrogenase and coenzyme regeneration systems. By the method, racemized D,L-phosphinothricin serves as the raw material, the D-phosphinothricin is oxidized into 2-carbonyl-4-(hydroxymethylphosphonyl)-butyric acid by the D-amino acid oxidase, and the L-phosphinothricin does not take part in the reaction and is completely retained; but the 2-carbonyl-4-(hydroxymethylphosphonyl)-butyric acid is catalytically reduced into the L-phosphinothricin by the amino acid dehydrogenase, so that in-situ deracemization of the D,L-phosphinothricin is realized, the obtained L-phosphinothricin does not contain other side products, the total yield of the products is more than or equal to 99 percent, and the optical purify can exceed 99 percent.

The invention discloses a preparation method and application of a non-enzymatic electrochemical immunosensor based on dopamine biomemetic modification and relates to the fields of nano-science, biological immune technology, electrochemical sensing and the like. An electrode is functionalized by utilizing dopamine biomemetic modification, and platinum, silver, palladium and other metal nanoparticles with enzymatic activity are synthesized in situ by utilizing the reduction characteristic of a poly-dopamine modification layer; an antibody is immobilized on the surface of the electrode by means of the interaction of the metal nanoparticles and poly-dopamine modification layer; electrochemical immunoassay on a tumor marker can be realized based on the electrocatalytic effect of the metal nanoparticles to an H2O2 reduction reaction and the identification effect of the antibody molecule to an antigen. The method is simple in steps, easy to operate and low in cost, has a high electrochemical activity and excellent response performance, can solve the problem of difficult nano-material synthesis in a conventional method and lack of simple and effective method, is applicable to preparation of multiple tumor marker immunosensor electrodes, and has a wide application prospect in scientific research and clinical application.

Disclosed are compositions and a method for of amplifying nucleic acid sequences useful for detecting the presence of molecules of interest. The method is useful for detecting specific nucleic acids in a sample with high specificity and sensitivity. The method also has an inherently low level of background signal. A preferred form of the method consists of a DNA ligation operation, an amplification operation, and a detection operation. The DNA ligation operation circularizes a specially designed nucleic acid probe molecule. This operation is dependent on hybridization of the probe to a target sequence and forms circular probe molecules in proportion to the amount of target sequence present in a sample. The amplification operation is rolling circle replication of the circularized probe. A single round of amplification using rolling circle replication results in a large amplification of the circularized probe sequences. Following rolling circle replication, the amplified probe sequences are detected and quantified using any of the conventional detection systems for nucleic acids such as detection of fluorescent labels, enzyme-linked detection systems, antibody-mediated label detection, and detection of radioactive labels. Because, the amplified product is directly proportional to the amount of target sequence present in a sample, quantitative measurements reliably represent the amount of a target sequence in a sample. Major advantages of this method are that the ligation step can be manipulated to obtain allelic discrimination, the DNA replication step is isothermal, and signals are strictly quantitative because the amplification reaction is linear and is catalyzed by a highly processive enzyme. In multiplex assays, the primer oligonucleotide used for the DNA polymerase reaction can be the same for all probes. Also described are modes of the method in which additional amplification is obtained using a cascade of strand displacement reactions.

The invention relates to a simple preparing method of molecularly imprinted polymeric microspheres applicable to an aqueous solution system. Crosslinking degree of the molecularly imprinted polymeric microspheres is larger than 50%, grain size of each molecularly imprinted polymeric microsphere ranges from 0.2-5 micrometers, and hydrophilic macromolecule brushes are grated on the surfaces of the molecularly imprinted polymeric microspheres. The molecularly imprinted polymeric microspheres are synthesized in one step via a reversible addition-fragmentation chain transfer (RAFT) precipitation polymerization technology induced by hydrophilic macromolecular chain transfer agent. The preparing method is simple in synthesis, wide in application range, pure in product and the like. The molecularly imprinted polymeric microspheres prepared by the method have wide application prospect in multiple fields including chromatographic support, biological sample analysis, medical clinical immunoassay, food and environmental monitoring, mimic enzyme catalysis, biomimetic sensor and the like.

The invention belongs to the technical field of deep processing and modification of oil, and particularly discloses a method for preparing glyceride rich in EPA and DHA through enzyme catalysis .Fish oil rich in EPA and DHA is used as the raw material, efficient selective catalysis of fish oil hydrolysis is conducted with lipase, and glyceride rich in EPA and DHA is obtained through molecular distillation separation purification by strictly controlling hydrolysis conditions including enzyme adding amount, pH, water-oil ratio, temperature and time .To increase the utilization rate of raw materials, EPA and DHA in a free fatty acid product obtained through molecular distillation are recovered with the urea coating method, so that transesterification can be conducted between EPA and DHA subjected to ethyl esterification and glyceride obtained through molecular distillation and rich in EPA and DHA, and the content of triacylglycerol, the content of EPA and the content of DHA in glyceride are further increased .The content of EPA and the content of DHA in triacylglycerol type fish oil obtained with the method can be increased by 25% and 15% or more respectively.

The invention relates to a sensor, in particular to a polymer liquid film potential sensor for detecting enzymatic activity and a detection method thereof. A potential detector is respectively connected with an internal reference electrode and an external reference electrode through wires, the internal reference electrode is inserted in a working electrode filled with internal liquid, the working electrode and the external reference electrode are inserted in a detection pool with detection liquid, the working electrode is an electrode carrier on which a polymer sensitive film is fixed, and a power device with a solution disturbance function is arranged in the detection pool. According the detection method, the potential detector is used for detecting the change of the potential of the polymer sensitive film at the bottom of the working electrode before and after enzymatic reaction, and the enzymatic activity concentration can be detected on the basis of a standard working curve according to a potential change signal. The potential sensor has the advantages of high generality, good selectivity, high sensitivity and low cost and is suitable for detection under a complicated matrix condition.

The invention relates to a surface-hydrophilic molecularly imprinted polymer microsphere and a preparation method thereof. The molecularly imprinted polymer microsphere has the crosslinking degree of over 60 percent and a grain size of 1 to 5mu m. The surface of the microsphere is provided with a hydrophilic polymer brush, and the microsphere has excellent molecular recognition performance on template molecules in a pure aqueous solution system. The microspheres are synthesized by a two-step process in reversible addition fragmentation chain transfer (RAFT) controlled free radical polymerization technology. The invention has the advantages of simple synthesis method, wide application range, pure products and the like. The prepared molecularly imprinted polymer microsphere has a wide application prospect in the fields of chromatographic stationary phases, biological sample analysis, medically clinical immunoassay, food and environment monitoring, mimic enzyme catalysis, bionic sensors and the like.

The invention discloses a method for preparing functional grease by enzyme catalysis and modification on tea oil, comprising the following steps of: mixing tea oil and middle carbon chain fatty acid which are used as raw materials in the mole ratio of 1:(1-1):12; adding water accounting for 0.01-2 percent of the weight of the raw materials; not taking organic solvent as a medium in a nonaqueous phase system, passing through a packed column filled with 1,3-specific immobilized lipase in reverse flow way; reacting at 30DEG C-80 DEG C for 0.5h-3h; and separating the product to obtain grease withrapid energy supply and low heat quantity function, wherein in the functional grease, the middle carbon chain fatty acid is mainly positioned on the sn-1,3 site of triglycercide and unsaturated oleicacid of the fatty acid is mainly positioned on sn-2 site of the triglycercide. The invention can achieve favorable effects of maintaining the stable catalytic activity of enzyme and prolonging the service period of the enzyme by adding a proper amount of water in the raw materials.

The invention discloses an alcohol dehydrogenase, a gene thereof, a recombinant expression vector and a recombinant expression transformant respectively containing the gene, a recombinase of the alcohol dehydrogenase, and an application of the alcohol dehydrogenase in asymmetric reduction synthesis of chiral diaryl secondary alcohol as a catalyst, and belongs to the technical field of bioengineering. The alcohol dehydrogenase is from Kluyveromyces sp. CCTCCM2011385, has a carbonyl group reduction function, and also has a hydroxy group oxidation function. Extra addition of glucose dehydrogenase and other enzymes used for cofactor circulation is not needed when the alcohol dehydrogenase is used in the reduction of diaryl ketone into the chiral diaryl secondary alcohol as a biocatalyst, and the alcohol dehydrogenase has the advantages of high catalysis efficiency, mild reaction conditions, easy product recovery and low cost, so the alcohol dehydrogenase has very good application and exploitation prospect in the production of antihistamine medicines.

A method for catalyzing and synthetizing modified stevioside by using microwave auxiliary cyclodextrin glucosyltransferase relates to the technical field of biosynthesis of organic compounds, and comprises the following steps: taking stevioside aqueous solution and starch hydrolyzates as raw materials, and synthetizing stevioside replaced by glucose residue under the combined action of microwave radiation and CGTase catalysis in a microwave reaction device. In the process condition provided by the invention, enzyme catalysis reaction can be remarkably quickened, and the phenomenon that microwave of a water system enable enzyme to be inactive under the usual condition. Through tasting, the bitter taste of the synthetic modified stevioside is greatly reduced.