754 results about "Glycosyl" patented technology

The invention discloses a glycosyl transferase UGT76G1 mutant and a method for catalytically synthesizing rebaudioside M by using the glycosyl transferase UGT76G1 mutant, and relates to the technical field of biological catalytic synthesis. The glycosyl transferase UGT76G1 mutant is any one of the following components (A)-(C): (A) a protein obtained by performing any one or more of the following mutations on the basis of an amino acid sequence as shown in SEQ ID NO.1: the 89th amino acid is mutated into H from M; the 380th amino acid is mutated from L to M; the 411th amino acid is mutated from A to Y; (B) a protein which has 95% or 98% or more of identity with the amino acid sequence defined by (A) and has the same function as the amino acid sequence defined by (A); and (C) a fusion protein obtained by connecting a tag to the terminal of the protein defined in (A) or (B). The glycosyl transferase UGT76G1 mutant disclosed by the invention is obtained by mutating and screening glycosyl transferase UGT76G1, has higher catalytic activity, and can be used for efficiently synthesizing rebaudioside M by taking rebaudioside D and UDPG as substrates.

The invention provides infant formula milk powder for improving intestinal inflammation and / or microbial disorder as well as a preparation method and application of the infant formula milk powder. The invention provides infant formula milk powder for the first time, the infant formula milk powder comprises 2 '-fucosyllactose and lactose-N-neotetraose, and the mass ratio of the 2'-fucosyllactose to the lactose-N-neotetraose is (1-5.5): 1. The infant formula milk powder can improve intestinal inflammation and / or microbial disorder.

The invention relates to a gene modified cell and a method for producing fucosyllactose by using the gene modified cell, in particular to a saccharomyces cerevisiae gene modified cell and application thereof, and belongs to the technical field of biological gene engineering. The present invention provides a genetically modified cell comprising a recombinant nucleic acid sequence encoding a polypeptide having an [alpha]-1, 2-fucosyltransferase polypeptide ([alpha]-1, 2-fucosyltransferase) activity. The alpha-1, 2-fucosyltransferase polypeptide includes, but is not limited to, polypeptides having at least 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99% and 100% identical amino acid sequences with the amino acid sequences of SEQ ID NO: 1-25. According to the gene modified cell, the fucosyllactose synthesis capability of an original strain is improved.

The invention discloses construction and optimization of a gene editing tool based on CRISPR (clustered regularly interspaced short palindromic repeats)-associated transsposases and application of the gene editing tool in escherichia coli, and belongs to the field of synthetic biology and gene engineering. According to the invention, an efficient gene editing system is established in Escherichia coli, and the burden of a MUSCULAR-CAST system on strains is reduced through element optimization; by eliminating the self-targeting effect, large-fragment (> 10k bp) target gene expression cassettes can be efficiently integrated, and the editing degree of the gene editing system is improved. According to the invention, a MUSCULAR-CAST gene editing system is used for constructing the chassis strains for producing 3-fucosyllactose, L-tryptophan, 2 '-fucosyllactose and neotetraose, so that the chassis strains have equivalent or higher expression yield compared with plasmids, and the growth condition is better or the conversion rate is higher.

The invention provides an application of citrus flavonoid glycosyl transferase CitUGT73A78 in biosynthesis of flavonoid glycoside, and belongs to the technical field of gene engineering and enzyme engineering. According to the present invention, the function of the CitUGT73A78 gene is cloned and verified, and the in vitro enzyme activity test proves that the CitUGT73A78 recombinant protein has broad-spectrum catalytic activity, and can efficiently catalyze the glucosylation of a variety of flavonoids so as to generate the corresponding flavonoids 7-O-glucoside and / or flavonoids 4 '-O-glucoside. An in-vivo transient overexpression test also proves that the CitUGT73A78 gene has a promoting effect on the accumulation of the content of the citrus flavonoid 7-O-glucoside. The invention not only provides a preparation method for the production of flavonoid 4 '-O-glucoside, has the advantages of simplicity, convenience, high catalytic efficiency, low cost, greenness and safety, but also can be applied to nutritional quality improvement and germplasm innovation of citrus fruits.

The invention provides an enzyme modification method based on artificial intelligence. The enzyme modification method comprises the following steps: training an AlphaFold2 model to obtain a glycosyltransferase tertiary structure prediction model; performing multi-sequence comparison on the protein and nucleic acid sequence database and the non-redundant protein feature sequence database based on the active point location recognition model to obtain a comparison result; initializing a matrix of which the length is equal to that of a comparison result, so as to construct a PSSM matrix and screen out potential mutation sites; according to the screened potential mutation sites, constructing an initial mutation library to form a virtual screening mutation library; performing structure reconstruction on the sequence in the virtual screening mutation library based on a glycosyl transferase tertiary structure prediction model so as to predict the glycosyl transferase tertiary structure and perform molecular docking and dynamic simulation on the glycosyl transferase tertiary structure; the method is used for analyzing binding pockets of proteins and ligands and determining dynamic interaction of amino acid residues and ligands in the binding pockets, and the contact number of each amino acid residue and the ligands is used for modifying the tertiary structure of the glycosyltransferase.

The invention belongs to the technical field of organic compounds, and particularly relates to a multifunctional organic silicon glycosyl amide cationic surfactant as well as a preparation method and application thereof. The preparation method of the surfactant comprises the following steps: carrying out amine ester reaction on glucolactone and N, N-dimethyl dipropylene triamine to obtain a precursor; carrying out substitution reaction on the precursor and bromododecane to obtain an intermediate; the intermediate and 3-chloropropyl methyl dimethoxy silane or 3-chloropropyl methyl trimethoxy silane are subjected to a quaternization reaction, and the surfactant is obtained. The surfactant has good environmental protection property and biocompatibility, is non-toxic and non-irritant, can sterilize and improve the rewettability of the material surface, and has wide application prospects in the aspects of pesticide, textile, daily chemical industry and material transportation and storage.

The invention belongs to the field of nutrient substance research, and particularly relates to application of a nutrient composition to regulation of brain immunity. The invention provides application of a nutritional composition in preparation of food for regulating brain immunity. Wherein the nutritional composition comprises the following necessary components: lactoferrin and fucosyllactose, and in the nutritional composition, the mass ratio of the lactoferrin to the fucosyllactose is 1: (0.1-30). Research finds that after lactoferrin and fucosyllactose are combined according to a certain proportion, the lactoferrin and fucosyllactose have a synergistic effect of regulating brain immunity. Experimental data show that after the combination of lactoferrin and fucosyllactose is used for treating the BV2 cells, the trend that the BV2 cells are differentiated into M2 phenotype microglial cells is higher than the trend that the BV2 cells are differentiated into M1 phenotype microglial cells, and the amount of secreted inflammatory factors is obviously reduced.

The invention relates to 2 '-fucosyllactose, in particular to application of the 2'-fucosyllactose to preparation of immune balance drugs or food. The immune balance comprises regulation and control of the ratio of Th17 cells to Treg cells of Th17 / Treg immune imbalance offspring activated by maternal immune or induced by virus infection; according to the application disclosed by the invention, the fact that filial generations generated after the maternal body of a mammal generates immune reaction activation can regulate and control the proportion of Th17 and Treg cells through the influence of 2 '-fucosyllactose on intestinal flora is found, so that Th17 and Treg immune balance is realized; in addition, social and cognitive disorders and repetitive behaviors related to filial generation autism induced by Th17 / Treg immune imbalance can be improved.

The invention discloses a composition for improving bone density and application thereof, and belongs to the technical field of food. According to the invention, the 1, 3-dioleic acid-2-palmitin, the osteopontin and the oligosaccharide are compounded for use, and the components interact to promote mutual absorption and utilization, so that the growth and development of bones in the growth period of infants are improved, the mineral content and the bone mineral density of the bones are increased, the health of the bones is promoted, and the composition is safe and free of side effects. And by optimizing the variety of the oligosaccharide, the compound use of the galactooligosaccharide and the 2 '-fucosyllactose is found to be capable of better improving the growth and development of bones in the growth period of the infants.

The invention belongs to the technical field of nutritious food, and discloses a composition for simulating whole breast milk oligosaccharide and application of the composition. In the composition for simulating the whole breast milk oligosaccharide, the mass ratio of 2 '-fucosyllactose to lactose-N-neotetraose to 3'-sialyllactose is (3.9-8.1): (0.8-1.2): (0.8-1.2), and the breast milk oligosaccharide 2 '-fucosyllactose, the lactose-N-neotetraose and the 3'-sialyllactose are mutually matched to take effect in a synergistic manner, so that the whole breast milk oligosaccharide is obtained. The composition can improve the memory ability and cognitive ability of an eating object, can be added into infant food (including infant formula powder, complementary food and nutritional supplements) and nutritional supplements or food of children over 3 years old, teenagers and aged people, and has a wide application prospect.

The invention belongs to the technical field of food, and relates to application of breast milk oligosaccharide in regulating brain immunity. Specifically, the invention relates to the non-therapeutic purpose of adjusting brain immunity by adjusting polarization of microglial cells M1 / M2, and the breast milk oligosaccharide is any one of 3-fucosyllactose, lactose-N-tetraose, lactose-N-neotetraose, 3 '-sialic acid lactose and 6'-sialic acid lactose. Research results show that a specific variety of breast milk oligosaccharides (especially 3-FL) can obviously inhibit the generation of neurotoxic factors NO, inflammatory factors TNF-alpha and IL-1beta in microglial cells, and promote the generation of anti-inflammatory cytokines IL-10 in the microglial cells, so that the state of the microglial cells is improved, damage repair is promoted, and the microglial cells are prevented from being damaged. Therefore, the effect of regulating brain immunity is achieved.

The invention provides a composition for promoting bone health and bone formation as well as application and a product thereof, and belongs to the field of foods. The composition disclosed by the invention is prepared from the following components in parts by weight: 1 to 5 parts of osteopontin, 1 to 50 parts of 2 '-fucosyllactose and 0.05 to 50 parts of a calcium source. The composition disclosed by the invention shows a relatively good synergistic effect in promoting calcium absorption, and can be used for improving bone density, preventing and treating osteoporosis and the like.

The invention relates to the technical field of gene engineering, in particular to a glycosyl transferase mutant, a sucrose synthase mutant and application of the glycosyl transferase mutant and the sucrose synthase mutant in synthesis of rebaudioside M. Wild glycosyl transferase and wild sucrose synthase are modified according to a directed evolution theory to obtain a glycosyl transferase mutant and a sucrose synthase mutant. Rebaudioside M is obtained by catalyzing rebaudioside D through a glycosyl transferase mutant and sucrose synthase mutant co-expression strain, and the catalytic efficiency is superior to that of a wild enzyme. The rebaudioside M is obtained by completely catalyzing 110 g / L of rebaudioside D through the co-expression strain of the glycosyl transferase mutant and the sucrose synthase mutant, only 20 h is needed, the conversion rate reaches 97%, the yield of the rebaudioside M reaches 122 g / L, the raw material conversion rate and the yield of the rebaudioside M are effectively increased, and meanwhile the synthesis time is shortened.

The invention relates to the technical field of oilfield chemistry, in particular to a glycosyl anionic surfactant and a preparation method and application thereof, and the glycosyl anionic surfactant is prepared from glucose, long-chain alkyl primary amine and succinic anhydride sodium hydroxide. The glycosyl anionic surfactant has excellent surface activity, is simple in preparation method, high in product yield, safe and reliable, can be used for oil displacement agents, polymer surface oil displacement agents, emulsifiers, discharge aiding agents, heavy oil viscosity reducers and the like, is wide in application, and meets the green development requirements of oil fields. The acid fracturing discharge aiding agent using the glycosyl anionic surfactant as a raw material can effectively reduce the surface and interfacial tension of an aqueous solution, and meets the technical specification of the acid fracturing discharge aiding agent.

The invention provides a children formula food for improving intestinal inflammation and / or microbial disorder as well as a preparation method and application of the children formula food. The invention firstly provides the infant formula food, the infant formula food is infant formula food or child formula food, the infant formula food comprises 2 '-fucosyllactose and lactose-N-neotetraose, and the mass ratio of the 2'-fucosyllactose to the lactose-N-neotetraose is (1-5.5): 1. The children formula food can improve intestinal inflammation and / or microbial disorder.

The invention discloses a preparation method of glucosyl stevioside, and relates to the technical field of glucosyl stevioside production, rebaudioside A or stevioside is taken as a raw material, cyclodextrin is taken as an auxiliary material, cyclodextrin glucosyltransferase is added for glycosylation reaction, a glucosyl stevioside solution I is cooled, and a glucosyl stevioside solution II is obtained; the method comprises the following steps: adding sucrose, UGT glycosyl transferase, sucrose synthase and uridine diphosphate into rebaudioside A or stevioside, continuously converting unreacted rebaudioside A or stevioside into rebaudioside D or rebaudioside E, inactivating after the reaction is finished, filtering by a plate frame, removing impurities through resin, analyzing the resin by using ethanol to obtain an analysis solution, and treating the analysis solution at 78-82 DEG C for 2-4 hours to obtain the rebaudioside D or rebaudioside E; and dealcoholizing at the vacuum degree of-0.1 MPa, concentrating and drying to obtain the glucosyl stevioside. The quality of the product is improved, the cost is reduced, and the taste of the product is integrally improved.

According to the invention, a glycosyl transferase mutant derived from Bacillus licheniformis ZSP01 is used as a research object, AlphaFold 2 is used for constructing a three-dimensional structure of a protein, then technologies such as molecular docking and molecular dynamics simulation are used for analyzing amino acids far away from a catalytic center in glycosyl transferase, site-directed mutagenesis is carried out on the amino acids, and the glycosyl transferase is obtained. The activity of the mutant for catalytically synthesizing the icariside D2 glycosyltransferase is improved.

The invention belongs to the field of food, and particularly relates to a nutritional composition of oligosaccharide and probiotics and application of the nutritional composition. The invention provides application of a nutritional composition in preparation of food beneficial to improvement of constipation and improvement of cognitive competence decline caused by constipation. Wherein the nutritional composition comprises the following components (i) and (ii): (i) a neutral fucosylated breast milk oligosaccharide, and (ii) a bifidobacterium probiotic; wherein the neutral fucosylated breast milk oligosaccharide at least comprises 2 '-fucosylated lactose, and the bifidobacterium probiotics at least comprise bifidobacterium longum subsp. Longum. According to the present invention, with the substance combination of the neutral fucosylated breast milk oligosaccharide and the bifidobacterium probiotic, the abnormal brain-intestine interaction can be improved, such that the constipation can be easily improved, and the cognitive ability reduction caused by the constipation can be easily improved;

The invention relates to recombinant escherichia coli and a method for synthesizing sialic acid lactose-N-tetrasaccharide c, and belongs to the technical field of microbial metabolism engineering. According to the research, engineering escherichia coli BAZ for producing LNTri II is taken as an initial strain, two key glycosyl transferases, namely beta 1, 4-galactosyl transferase and alpha 2, 6-sialyltransferase, and three CMP-Neu5Ac pathway enzymes, namely NeuC, NeuB and NeuA, are introduced, and related competitive genes are knocked out; under the conditions of shake-flask culture and fed batch culture, the LST c yield of 1.718 g / L and the LST c yield of 9.745 g / L are achieved through the engineering bacterium respectively, and the huge potential of a microbial cell factory in the aspect of efficient production of complex breast milk oligosaccharides is shown.

The invention provides application of acidophilous glycosyltransferase in salidroside production, and belongs to the technical field of biological engineering. The problem of producing salidroside under the acidic condition is solved. Comprising an application of acidophilous glycosyl transferase with an amino acid sequence as shown in SEQ ID NO.1 in salidroside production under an acidic condition and an acidophilous escherichia coli engineering strain for producing salidroside. The escherichia coli engineering strain overexpresses a mutant 3-deoxy-D-arabinoheptulose-7-phosphate (DAHP) synthetase gene aroGfbr, a cyclohexadiene dehydrogenase gene tyrC, a glucose phosphate mutant enzyme gene pgm and a UDP-glucose pyrophosphorylase galU, overexpresses a phenylpyruvate decarboxylase gene ARO10 derived from saccharomyces cerevisiae, and can be used for producing a mutant 3-deoxy-D-arabinoheptulose-7-phosphate mutant enzyme. The kit comprises an ethanol dehydrogenase gene ADH6 and a glycosyl transferase gene LrUGT85AF8. The method is mainly used for producing salidroside under an acidic condition.

The invention relates to the technical field of fermentation engineering, in particular to a method for analyzing carbohydrates in a 2 '-fucosyllactose product. The carbohydrate analysis method comprises the following steps: aiming at a 2 '-fucosyllactose product, separating carbohydrates through ion exchange chromatography, and the conditions are as follows: a mobile phase A comprises 4-6mM NaOH and 1-3mM NaAC; the mobile phase B is prepared from 80 to 120 mM of NaOH and 80 to 120 mM of NaAC; the elution procedure is a specific gradient elution procedure. According to the carbohydrate analysis method of the 2 '-fucosyllactose product, provided by the invention, miscellaneous sugar with relatively high similarity with the 2'-fucosyllactose in the 2 '-fucosyllactose product can be effectively separated, so that the analysis efficiency and accuracy of carbohydrates in the 2'-fucosyllactose product can be effectively improved; the method has important significance in the related production field of 2 '-fucosyllactose.

The invention discloses a water-soluble bornyl ester compound and application thereof, the structure of the water-soluble bornyl ester compound is as shown in general formula I, R is acetic acid 2-oxoethyl ester of organic heterocyclic ring, amino acid 2-oxoethyl ester, glycolate of amino acid, acetal of monodisperse polyethylene glycol chain, carbonate, ester or glycosyl; the compound is good in water solubility, the problems that borneol is difficult to dissolve in water and difficult to prepare can be well solved, and in an inflammatory depression animal model, the bornyl ester compound shows good anti-inflammatory, anti-depression and cerebral apoplexy treatment effects and has great application prospects.

The invention belongs to the field of food, and particularly relates to application of a nutritional composition for assisting in improving memory ability. The invention provides application of a nutritional composition in preparation of food for assisting in improving memory ability of offspring. The nutritional composition comprises the following necessary components: active folic acid substances and fucosyllactose, moreover, in the nutritional composition, the mass ratio of the active folic acid substance to the fucosyllactose is (0.0001-0.0015): (0.5-10), the food is ingested by a mother to play the role of assisting in improving the memory ability of the offspring, the mother is in a gestation period and / or a lactation period, and the maternal is in the gestation period and / or the lactation period. The filial generation comprises a fetal-stage filial generation and / or an infant-stage filial generation and an optional child-stage filial generation. A large number of studies find that when active folic acid substances and fucosyllactose which are combined according to a certain proportion are supplemented to a mother at the beginning of the gestation period, the memory ability of offspring can be remarkably improved in an auxiliary mode.

The invention relates to the technical field of industrial microorganisms and food industry, and discloses an immobilized enzyme composition and application thereof in efficient preparation of rebaudioside M. The immobilized enzyme composition provided by the invention comprises immobilized UDP-glycosyl transferase UGT and immobilized UDP-glycosyl transferase UGT76G1 according to a mass ratio of (1 to 2): (1 to 3). By adopting the immobilized enzyme composition disclosed by the invention, the rebaudioside A can be synergistically and efficiently promoted to be converted into the rebaudioside M, and the conversion rate is up to 85% or above and can be up to 97% at most; the working efficiency of the enzyme is remarkably improved, and the rebaudioside M is efficiently prepared; meanwhile, the enzyme is good in stability and can be repeatedly used for at least five times, and the catalytic efficiency is still higher than 95%. The method has great popularization and application values.

According to the present invention, glycosyl transferase UGTBL1 derived from Bacillus licheniformis ZSP01 is adopted as a research object, AlphaFold 2 is adopted to carry out modeling, molecular docking, molecular dynamics simulation and other technologies, amino acids in an active pocket region of glycosyl transferase are analyzed, site-directed mutagenesis is performed on the amino acids to obtain a series of glycosyl transferase mutants, and salidroside can be highly selectively catalyzed and synthesized.

The invention discloses an efficient extraction method of large-molecular-weight astragalus polysaccharide, which belongs to the technical field of plant extraction, and comprises the following steps: cleaning astragalus, filtering, and crushing; the preparation method comprises the following steps: mixing a beta-1, 3-glucanase aqueous solution and trehalose ethylene diamine, and stirring for 10-30 minutes to obtain an enzyme protection system; soaking the radix astragali powder in a citric acid solution, adding an enzyme protection system, applying a bipolar pulsed electric field, and reacting at 40-60 DEG C for 30-40 minutes; adjusting the concentration of the ethanol to 40-50%, standing, centrifuging and collecting crude astragalus polysaccharide; purifying, decolorizing, concentrating, freeze-drying and crushing the crude astragalus polysaccharide to obtain refined astragalus polysaccharide; the mass ratio of the trehalose ethylene diamine to the beta-1, 3-glucanase is (15: 1) to (30: 1). The enzyme protection system maintains the activity of the enzyme, the enzyme and the pulsed electric field act synergistically, the extraction time is shortened, and the extraction rate is increased while the astragalus polysaccharide with large molecular weight is obtained.

The invention discloses a method for constructing an N-glycosylation spectrum type biological age evaluation model based on plasma immunoglobulin G and application of the biological age evaluation model. Based on a glycosyl quantitative result, a clinical biochemical detection index, a lifestyle measurement index, a multi-dimensional health score and the like, a glycosyl metabolic index, a glycosyl inflammation index, a glycosyl cardiovascular index, a glycosyl stroke index, a glycosyl liver index and a glycosyl kidney index are fitted. And inputting the obtained different glycosyl data into the model, and speculating the aging process and health risk of each organ system of the detected person according to the risk threshold in the early-stage crowd. The method can predict a'glycosyl biological age system 'which can reflect health level and disease risk better than'calendar age', has individual specificity, is very sensitive to change of inflammatory response in vivo, is relatively stable in a short time, can be used as an index for early detection and screening of senescence, and can be used as an index for early detection and screening of senescence. And thus, effective reference is provided for individualized health suggestions of the detected personnel.

The invention belongs to the field of chemical synthesis, and particularly relates to four acinetobacter baumannii cell wall oligosaccharide fragments as well as a synthesis method and application thereof. Four acinetobacter baumannii core oligosaccharide fragments are synthesized by adopting a divergent synthesis strategy, compounds 1-3 take orthogonally protected alpha-(2-> 5)-Kdo-Kdo disaccharide as key precursors, protecting groups at different sites are selectively removed, glycosyl is introduced through a stereoselective glycosylation reaction, and thus a target molecular skeleton is constructed. The method disclosed by the invention and the four finally prepared acinetobacter baumannii core oligosaccharide fragments have huge industrial application potential.

The invention discloses recombinant escherichia coli capable of increasing the yield of fucosyllactose and a construction method and application of a fucosyltransferase mutant of the recombinant escherichia coli, and belongs to the field of synthetic biology and metabolic engineering. According to the invention, recombinant escherichia coli B20 and B21 are constructed based on key enzyme engineering transformation. Under the shake flask condition, the 3-FL production capacity of the recombinant strain is obviously improved to 6.20 g / L and 6.34 g / L from the initial 3.45 g / L, and the amplification reaches 79.7% and 83.8% respectively. The yields of 3-FL of the strain B20 and the strain B21 respectively reach 53.88 g / L and 54.64 g / L under the culture condition of a 3L fermentation tank. The recombinant escherichia coli for expressing the 2 '-FL is constructed, and the yield of the 2'-FL reaches 64.86 g / L in a 3L fermentation tank. The invention provides a new technical scheme for efficient microbial synthesis of the 3-FL.