10 results about "Microbial transglutaminase" patented technology

The invention discloses starch-collagen composite hydrogel as well as a preparation method and application thereof. Collagen is catalyzed by microbial transglutaminase to form a covalent cross-linked network, and meanwhile, hydroxypropyl starch is introduced to construct a physical interpenetrating network through molecular chain penetration and hydrogen-bond interaction; and chondroitin sulfate is further integrated to strengthen the network structure and biological activity through electrostatic interaction. The method is mild in condition and does not need a toxic chemical cross-linking agent, the obtained composite hydrogel has an interpenetrating double-network structure and has excellent mechanical properties, enzymatic degradation resistance and cell affinity, the compression modulus of the composite hydrogel is remarkably improved, the composite hydrogel can keep structural stability for a long time in a collagenase environment, cell adhesion and proliferation can be effectively promoted, and the composite hydrogel has a good application prospect. The hydrogel can be widely applied to tissue engineering scaffolds, wound dressings, drug sustained-release carriers and cartilage repair materials.

The invention belongs to the field of marine food processing, and provides a marine food containing yellow croaker and a preparation method thereof.The marine food containing yellow croaker is prepared by adopting collaborative design of a minced yellow croaker protein-polysaccharide composite nano colloid powder intermediate and low-molecular fish collagen, through microbial transglutaminase cross-linking and cryoprotectant compounding regulation and control, and the marine food containing yellow croaker and the preparation method of the marine food containing yellow croaker are obtained. A minced fillet protein continuous phase network structure with uniformly dispersed nano-particles is constructed, the gel strength is 900-1300 g.cm, the gel strength retention rate is not lower than 80% after 6 times of freezing and thawing cycles are frozen for 3-5 times, the unfreezing drip loss is not higher than 8 wt%, the hardness is 1500-2500 g, and the taste characteristics of high strength and good elasticity are obtained. The technical problems that high gel strength and freeze-thaw stability of a traditional surimi product are difficult to consider, the taste is worse easily due to improvement of mechanical properties, nano-particles are difficult to uniformly disperse in a high-solid-content system and the like are solved, and the surimi product has wide application value in the fields of surimi products, quick-frozen prepared foods and marine functional foods.

The invention discloses cheese powder based on milk powder and a preparation method thereof, and the preparation method comprises the following steps: fully dissolving milk powder and casein micelle concentrate in water at 40-50 DEG C to form milk powder base liquid with the solid content of 25-30%; the addition amount of the casein micelle concentrate is 2-6% of the total mass of the milk powder base solution; 0.07-0.23% of a compound enzyme preparation is added into the milk powder base liquid for an enzymolysis reaction; adding 0.1-0.3% of microbial transglutaminase into the milk powder base solution subjected to enzymolysis, and carrying out a cross-linking reaction; sequentially adding a flavor enhancer and a stabilizer into the reacted milk powder base liquid; and carrying out spray drying on the milk powder base liquid to obtain cheese powder. The preparation method disclosed by the invention not only solves the problem of dependence on natural cheese resources in the prior art, but also effectively improves the product quality stability and the production efficiency.

The invention belongs to the technical field of biomedical materials, and particularly relates to mTG hemostatic gel for digestive tract endoscopy and a preparation method of the mTG hemostatic gel, and the mTG hemostatic gel is prepared from the following raw materials in parts by mass: 45-65 parts of tyrosine grafted gelatin nanofiber, 10-20 parts of catechoyl alanine, 3-6 parts of glycerol, 0.2-0.4 part of calcium lactate, 8-42 parts of physiological buffer solution and 5-10 parts of microbial transglutaminase. The preparation method comprises the following steps: uniformly mixing the raw materials, and performing catalytic cross-linking formation under a neutral condition to form a gel network with strong tissue adhesion and good biocompatibility, so that the prepared gel can be quickly cured in a complex liquid environment of gastrointestinal tracts, the hemostasis efficiency and stability are remarkably improved, and the gel has the advantages of high gel forming speed, high shear strength, easiness in operation and stable structure in liquid; the device is suitable for local wound surface sealing and rapid hemostasis in endoscopic surgery, and has good clinical popularization value.

This application relates to site-specific conjugation of antibody lysine residues using solid phase immobilized microbial transglutaminase MTG and MTG in solution. Site-specific modification of proteins using microbial transglutaminase (MTG) is a powerful and versatile strategy for controlled modification of proteins under physiological conditions. We present evidence that solid phase microbead immobilization can be used to site-specifically and efficiently link different functional molecules important for further downstream applications to therapeutically relevant proteins, including scFV, Fab fragments and antibodies. We demonstrate that MTG remains firmly immobilized and there is no detectable column bleed and the enzyme activity is maintained during continuous operation, which allows for convenient recycling of the enzyme, thus outperforming solution phase MTG conjugation. Furthermore, it is shown that immobilized MTG exhibits an enhanced selectivity for certain residues in the presence of several reactive residues, all of which are targeted if conjugation is performed in solution. Site-specific lysine conjugation of antibodies using immobilized and solution MTG with a highly efficient glutamine-containing peptide is also reported. In addition, the generation of bis-site-specific conjugated IgGl with site-specific conjugation of both glutamine and lysine residues of an IgGl antibody using immobilized and solution MTG is reported. Site-specific glutamine conjugation with small peptides containing lysine residues and functional moieties is also described.

This invention belongs to the field of biomedical materials, and particularly relates to a hydrogel for cartilage repair and its preparation method. The preparation method of the hydrogel includes the following steps: (1) adding cross-linked modified chitosan and 8-O-acetylganoside methyl ester to a collagen solution, adjusting the pH to obtain a collagen polysaccharide solution; (2) adding metal ion microspheres to the collagen polysaccharide solution of step (1), stirring and reacting, then adding microbial transglutaminase for heating and reacting, adjusting the pH to obtain a mixed solution; (3) adding 1,4-butanediol diglycidyl ether and growth factors to the mixed solution of step (2), adjusting the pH, water bath, and dialysis to obtain the hydrogel. This preparation method is simple, and the obtained hydrogel has excellent mechanical strength and adhesion properties.

The invention discloses a DNA aptamer for recognizing microbial transglutaminase and a screening method of the DNA aptamer, and belongs to the technical field of molecular biological detection. According to the invention, the high-affinity and high-specificity DNA aptamer aiming at microbial transglutaminase (MTGase) is obtained through screening for the first time, and the blank of the target in the aptamer recognition field is filled. The reverse screening step is introduced in the screening process, so that non-specific binding sequences with coexisting proteins are effectively removed, and the selectivity of the aptamer is remarkably improved. By combining multiple means such as FP, ITC, CD and molecular docking, the binding capacity and mechanism of the aptamer are systematically verified, and the reliability and scientificity of a screening result are ensured. The obtained aptamer has excellent affinity with MTGase, the dissociation constant can reach the nanomole level, and a molecular basis is provided for subsequent development of related recognition and detection technologies.

The application belongs to the field of biomedical materials, and particularly relates to a hydrogel for cartilage repair and a preparation method thereof. The preparation method of the hydrogel comprises the following steps: (1) adding cross-linking modified chitosan and 8-O-acetylmagnol methyl ester into a collagen solution, adjusting pH to prepare a collagen polysaccharide solution; (2) adding metal ion microspheres into the collagen polysaccharide solution in step (1), stirring and reacting, then adding microbial transglutaminase for heating reaction, adjusting pH to prepare a mixed solution; and (3) adding 1,4-butanediol diglycidyl ether and growth factors into the mixed solution in step (2), adjusting pH, water-bathing and dialysis to prepare the hydrogel. The preparation method is simple in process, and the obtained hydrogel has excellent mechanical strength and adhesion.

The application relates to the technical field of biomaterials, and discloses a high-biocompatibility hydrogel based on enzyme catalysis cross-linking and a preparation method thereof, which comprises the following steps: mixing a polypeptide mother liquor containing a tyrosine residue, functional nanoparticle tyrosinase and an MES buffer solution to obtain precursor solution A; mixing gelatin, recombinant elastin and a phosphate buffered saline solution to obtain a polymer mother liquor, and adding microbial transglutaminase into the polymer mother liquor to obtain precursor solution B; and mixing and reacting the precursor solution A and the precursor solution B to obtain the high-biocompatibility hydrogel based on enzyme catalysis cross-linking. In the application, the interpenetrating network constructed by the tyrosinase and the microbial transglutaminase sequentially catalyzes a significant synergistic enhancement effect. In a hyperglycemic environment, a mesoporous silica nanoparticle built-in level connection system is automatically activated, realizing multiple effects of antibiosis, anti-inflammation and promotion of angiogenesis.

The present invention relates to a method for producing antibody-payload conjugates by microbial transglutaminase (MTG).SOLUTION: The method comprising conjugating a linker comprising the structure (shown in the N → C direction) (Sp1) - RK - (Sp2) - B - (Sp3) or (Sp1) - B - (Sp2) - RK - (Sp3) to Gln residues comprised in the antibodies, wherein (Sp1) is a chemical spacer or absent; (Sp2) is a chemical spacer or absent; (Sp3) is a chemical spacer or absent; R is arginine or an arginine derivative or arginine mimic, K is lysine or a lysine derivative or lysine mimic; B is a linking moiety or a payload, and the linker is conjugated to a Gln residue comprised in the antibody via a primary amine comprised in the side chain of the lysine residue, lysine derivative or lysine mimic.SELECTED DRAWING: None