33results about How to "Retain enzyme activity" patented technology

The invention discloses an arginine deiminase mutant from an arthritis-type mycoplasma, a gene, a polyethylene glycol modified substance and an application thereof. The arginine deiminase mutant is a dipolymer which is formed by two protein subunits, wherein amino sequences of the protein subunits are represented as SEQ ID No.2 in a sequence table. The arginine deiminase mutant is increased in expression quantity in escherichia coli, is increased in renaturation efficiency, is not changed in enzyme activity and is suitable for industrial production. The polyethylene glycol modified substance of the arginine deiminase mutant can be used for preparing anti-tumor drugs, such as anti-hepatoma drugs, anti-leukemia drugs and anti-melanoma drugs.

The invention relates to a β-galactosidase GalA and its application. The amino acid sequence of the β-galactosidase GalA is shown in SEQ ID NO.1. The invention provides a preparation method for recombinant expression and purification of the β-galactosidase GalA, the enzyme activity of the fermentation broth can reach 3795.6 U / mL, the purity of one-step purification is >97%, and the recovery rate is 79.5%. The β-galactosidase GalA of the present invention has good thermal stability and storage stability, and the optimum reaction temperature is 50°C, and it still retains 89.7% of the enzyme activity after continuous incubation at 50°C for 24 h. At room temperature (30 ℃) stored for 30 days, still can retain 81.5% of the enzyme activity. The β-galactosidase GalA of the invention has high activity, good stability, strong ability to degrade lactose, and good application potential.

The invention relates to a manganese dioxide-based nanometer drug carrier, and innovatively combines starvation therapy and gas therapy for cancer treatment. Specifically, the use of amidation reaction was the first to introduce folic acid targeting molecules on human serum protein, and then the nano-manganese dioxide carrier was cultured in the protein by biomineralization method. Glucose oxidase and L-arginine were simultaneously loaded by physical adsorption. The advantages are: 1. The targeted drug delivery efficiency and dispersibility of the nano-manganese dioxide are greatly improved. 2. Use specific chemical reactions in cancer cells to consume endogenous glucose and release nitric oxide gas to kill cancer cells through starvation and gas therapy. 3. The synthetic carrier material is degradable, and the loaded enzymes and amino acids are endogenous substances in the human body, which have no toxic and side effects on the human body. 4. Significant anti-cancer effect, can kill cancer cells at a very small concentration of biological enzymes.

The invention discloses a method for preparing a super paramagnetic carrier of a cross-linking immobilized lipase. The preparation of the super paramagnetic carrier is realized by preparing a nano-magnetic microsphere Fe3O4, coating the nano-magnetic microsphere Fe3O4, functionally modifying the coated nano-magnetic microsphere Fe3O4. A thermo-sensitive material, namely N-isopropylacrylamide, is introduced into the super paramagnetic carrier prepared according to the method, and the structural performance of the carrier can be changed through temperature control, so that the lipase which is immobilized through the super paramagnetic carrier can get out of the interface performance control to realize direct reactions among alcohols, acids and lipids, and separation of the reaction products is facilitated; moreover, lipase activity control through alpha coverage is facilitated. The super paramagnetic carrier is a super paramagnetic polymer microsphere based on the mode of lipase interface activity action; the lipase can be immobilized through the super paramagnetic polymer microsphere; the immobilized lipase is high in magnetic separation performance; 90% or higher of the lipase activity is kept; the detect that the lipase activity in an enzymatic reaction depends on the interface effect is overcome.

The invention discloses a method for preparing an exosome biomimetic preparation that synergistically promotes wound healing and its preparation. The preparation of the preparation includes: preparation of catalase-photosensitizer micelles, carrying catalase-photosensitizer Micellar ROS-responsive liposome preparation, exosome extraction, separation and purification, mixing liposomes and exosomes, extrusion mediating membrane fusion between liposomes and exosomes, and membrane fusion The carrier is mixed with the gel and stirred evenly. The preparation prepared by the present invention combines photodynamic therapy and biological therapy, uses membrane fusion carrier to wrap catalase-photosensitizer micelles, eliminates accumulated hydrogen peroxide on the wound surface and supplements oxygen, and the photosensitizer produces a controllable singlet state Oxygen anti-inflammatory and sterilizing creates favorable conditions for exosomes to treat wounds. At the same time, the gel itself also provides a favorable moist environment for wound healing. It has high safety, good stability, convenient application, simple processing technology, and low cost. It has a good application prospect.

The invention relates to the field of the preparation of fruit and vegetable enzyme, and in particular relates to a preparation method of cactus fruit and vegetable enzyme and prepared cactus fruit and vegetable enzyme. The preparation method of the cactus fruit and vegetable enzyme comprises the following steps: selecting cactus as well as fruits and vegetables, chopping or slicing the cactus as well as the fruits and vegetables so as to obtain fermentation materials; mixing a culture with the fermentation materials; adding the fermentation materials to a fermentation container in a mode of one layer of the fermentation materials and one layer of edible sugar, wherein the fermentation materials account for 1 / 2-3 / 4 of the volume of the fermentation container, the top layer is edible sugar and the ratio of the addition of the edible sugar to the weight of the fermentation materials is at (0.5-0.6): 1; after filling the tank, spraying edible white vinegar to the surfaces to the materials in the tank, and then fermenting for 150-200 days in a sealed manner so as to obtain the cactus fruit and vegetable enzyme. The preparation method of the cactus fruit and vegetable enzyme disclosed by the invention can eliminate uncontrollable factors in original natural fermentation through mixed fermentation of one or more probiotics, so that the safety of a finished product is improved. A substance obtained from fermentation is rich in nutritional component, and is especially high in SOD (superoxide dismutase) activity.