292 results about "Acetylglucosamine" patented technology

The invention discloses N-acetylglucosamine transferase AcetRL-R349H and an application thereof, and belongs to the technical field of functional enzymes. The amino acid sequence of the N-acetylglucosamine transferase AcetRL-R349H is as shown in SEQ ID NO. 5 (sequence identifier number 5). The invention further discloses the application of the N-acetylglucosamine transferase AcetRL-R349H in the preparation of the chitosan oligosaccharide. The N-acetylglucosamine transferase AcetRL-R349H disclosed by the invention is obtained by carrying out mutation modification on the N-acetylglucosamine transferase AcetRL, and can be used for producing the chitosan oligosaccharide with the polymerization degree of 4 to 6, especially (GlcNAc) 6. The product spectrum of the N-acetylglucosamine transferase is widened, and the N-acetylglucosamine transferase can be used for preparing high-polymerization-degree chitosan oligosaccharide and has a wide application prospect.

The invention discloses an N-acetylglucosamine transferase AcetRS-R346D and an application thereof, and belongs to the technical field of functional enzymes. And the amino acid sequence of the N-acetylglucosamine transferase AcetRS-R346D is as shown in SEQ ID NO. 3. The invention further discloses the application of the N-acetylglucosamine transferase AcetRS-R346D in the preparation of the chitosan oligosaccharide. The N-acetylglucosamine transferase AcetRS-R346D disclosed by the invention is obtained by carrying out mutation modification on the N-acetylglucosamine transferase AcetRS, and can be used for producing the chitosan oligosaccharide with the polymerization degree of 4 to 7, especially (GlcNAc) 7. The product spectrum of the N-acetylglucosamine transferase is widened, and the N-acetylglucosamine transferase can be used for preparing high-polymerization-degree chitosan oligosaccharide and has a wide application prospect.

The invention relates to a construction method of escherichia coli engineering bacteria with high yield of N-acetylglucosamine. According to the method, the metabolic network of escherichia coli is directionally modified through metabolic engineering, the problems of'product re-decomposition ', by-product accumulation, poor genetic stability and the like of natural strains are solved, and efficient industrial production of GlcNAc is realized.

The invention provides a treatment method for promoting germination of Cinnamomum tamala seeds, and relates to the technical field of artificial breeding of Cinnamomum tamala. The treatment method mainly comprises the following steps: carrying out ice-water ultrasonic treatment on fresh Cinnamomum camphora fruits, removing fake peels to obtain seeds, carrying out shock cooling variable-temperature pretreatment on the seeds, preparing a nutrient solution from gibberellin, tocopheryl acetate, N-acetylglucosamine, compound vitamins and compound amino acids, wetting paper by using the nutrient solution, wrapping the seeds, carrying out sowing management and the like. According to the method, the defects in the prior art are overcome, the germination rate of fresh camellia oleifera seed sowing is effectively increased, growth of early germination seedlings of camellia oleifera is promoted, and a good guiding effect is provided for artificial breeding and planting of camellia oleifera.

The invention discloses corynebacterium glutamicum for producing N-acetylglucosamine and application of the corynebacterium glutamicum, and belongs to the technical field of synthetic biology. Specifically, the corynebacterium glutamicum overexpresses a GNA1 gene from a brewer's yeast S288C controlled by a tacM promoter, a glmS gene from corynebacterium glutamicum S9114 and a yqab gene from escherichia coli K12 MG1655, and simultaneously has five gene defect types of nagA, nagB, ldhA, msccg and msccg2 in a genome and two gene single base mutation types of odhA and glnA, and the codon of the glnA for coding the 405th amino acid is mutated from TAC to TTC. By blocking excretion of glutamic acid of corynebacterium glutamicum and enhancing conversion of glutamic acid to glutamine, the supply capacity of a precursor of corynebacterium glutamicum is enhanced, and an optimal way for synthesizing N-acetylglucosamine is obtained, so that efficient production of N-acetylglucosamine in corynebacterium glutamicum is realized, and the yield of N-acetylglucosamine in corynebacterium glutamicum is increased. The method has important economic value and social significance.

The invention discloses a composition for promoting cartilage repair and maintaining joint health as well as a preparation process and application thereof, and relates to the technical field of functional foods. The composition is prepared from the following components in parts by weight: 21.1 to 90 parts of a multi-protein complex, 0.1 to 3 parts of cherry powder, 0.01 to 2 parts of N-acetylglucosamine, 0.01 to 2 parts of radix puerariae powder, 0.1 to 1.5 parts of a calcium compound and 0.01 to 0.2 part of rhizoma curcumae longae, the multi-protein compound is prepared from 0.1 to 10 parts of ray collagen peptide, 1 to 30 parts of bone collagen peptide powder and 20 to 50 parts of fish collagen peptide. The composition provided by the invention can promote cartilage repair, achieves the purpose of daily maintenance of joint health, and has a good application prospect.

The invention provides recombinant escherichia coli for producing chondroitin sulfate A and application of the recombinant escherichia coli, and relates to the technical field of genetic engineering. According to the recombinant escherichia coli disclosed by the invention, chondroitin synthase, chondroitin 4-O-sulfotransferase, N-acetyl glucosamine epimerase, UDP-glucose dehydrogenase and chondroitin sulfate degrading enzyme are overexpressed; wherein the amino acid sequence of the chondroitin sulfate degrading enzyme is as shown in SEQ ID NO. 5. The recombinant escherichia coli is inoculated into a culture medium for fermentation culture, the average molecular weight of the obtained chondroitin sulfate A is 800Da, and the yield is about 12.5 g / L. Therefore, low-molecular-weight chondroitin sulfate A can be obtained and the yield of chondroitin sulfate A can be increased by fermenting the recombinant escherichia coli disclosed by the invention.

The present invention provides a genetically engineered bacterium for synthesizing N-acetylglucosamine, a preparation method thereof, and an application thereof. The genetically engineered bacterium uses Escherichia coli as an initial bacterium, and related genes for the catabolism of N-acetylglucosamine are knocked out on the genome of the initial bacterium, and related genes for the metabolic synthesis of N-acetylglucosamine are overexpressed, so as to improve the production level of N-acetylglucosamine. Among them, the related genes for the catabolism of N-acetylglucosamine include any one or a combination of at least two of nagB, nagA, manX, nagE, nagK, or ptsG, and the related genes for the metabolic synthesis of N-acetylglucosamine include any one or a combination of at least two of glmS, gna1, glnA, yqaB, icaC, galP, or glk.

An acne clearing composition for optimizing skin grease mass, comprising the following components in parts by mass: 0.1-5 parts of a mango leaf extract, 0.1-10 parts of a guaiacum officinale extract, 0.1-10 parts of N-acetylglucosamine, 0.1-10 parts of a yeast extract, and 0.01-5 parts of EUK-134. The components of the acne clearing composition can cooperate with each other, so that optimization of sebum components, maintenance of the stability of proportions of saturated fatty acids / unsaturated fatty acids of the sebum components and inhibition of sebum peroxidation are realized on the whole, thereby achieving the effects of mildly clearing acnes and repairing a sebum layer barrier, and the acne clearing composition has excellent antibacterial performance. Moreover, the acne clearing composition can be added into cosmetics as an active ingredient, so that the cosmetics are mild and non-irritating, and the preparation method for the acne clearing composition is simple and uses easily obtained raw materials, thereby facilitating actual production.

The invention provides a genetically engineered bacterium for synthesizing N-acetylglucosamine and a preparation method and application thereof.The genetically engineered bacterium takes escherichia coli as an initial bacterium, genes related to N-acetylglucosamine catabolism are knocked out on a genome of the initial bacterium, genes related to N-acetylglucosamine metabolism synthesis are overexpressed, and the genetically engineered bacterium is obtained. Therefore, the production level of the N-acetylglucosamine is improved; wherein the related gene for catabolism of N-acetylglucosamine comprises any one or a combination of at least two of nagB, nagA, manX, nagE, nagK or ptsG, and the related gene for metabolic synthesis of N-acetylglucosamine comprises any one or a combination of at least two of glmS, gna1, glnA, yqaB, icaC, galP or glk.

This invention provides a composition for improving bone and joint health, its preparation method, and its application, relating to the field of bone and joint health products technology. By weight, the composition for improving bone and joint health comprises the following components: 0.5-5 parts collagen peptides, 5-30 parts mangosteen extract, 0.5-3 parts non-denatured type II collagen peptides, 0.1-2 parts milk mineral salts, 0.3-3 parts bone collagen peptides, 0.1-2 parts cartilage extract, 0.1-2 parts N-acetylglucosamine, 0.1-2 parts sodium hyaluronate, and 0.3-3 parts turmeric extract. This invention, through multiple combinations of mangosteen extract and turmeric extract, and cartilage extract and sodium hyaluronate, obtains a composition that is low in cost, highly safe, and has a good effect on the prevention or improvement of bone and joint diseases.

The present invention relates to antibody conjugates which are particularly suitable for targeting CEA-expressing cells, in particular tumor cells. An antibody conjugate according to the present invention has the structure (1): AB-[(L6) b-{Z-L-D} x] y (1) wherein AB is an antibody capable of targeting a tumor expressing CEA; l is a joint connecting Z to D; z is a linking group; l6 is-GlcNAc (Fuc) w-(G) j-S-(L7) w-wherein G is a monosaccharide, j is an integer in the range of 0 to 10, S is a sugar or a sugar derivative, GlcNAc is N-acetylglucosamine, and Fuc is fucose, w is 0 or 1, w'is 0, 1 or 2, and L7 is-N (H) C (O) CH2-,-N (H) C (O) CF2-or-CH2-; d is selected from the group consisting of an anthracycline, a camptothecin, a tubulysin, an endiyne, an amanitine, a duocarmycin, a maytansinoid, an aurestatin, eribulin, a BCL-XL inhibitor, a miscanthus hemiphyllum, a KSP inhibitor, a TLR agonist, an indolo-benzodiazepine # imgabs 0 # dimer or a pyrrolo-benzodiazepine # imgabs 1 # dimer (PBD), and analogs or prodrugs thereof; b is 0 or 1; x is 1 or 2; and y is 1, 2, 3 or 4. The invention further relates to a method for preparing said antibody conjugate of structure (1) and to the use of said antibody conjugate of structure (1).

The invention provides a genetically engineered bacterium for producing lactose-N-neotetraose as well as a construction method and application of the genetically engineered bacterium. The genetically engineered bacterium meets the following conditions: (1) exogenous expression of an MFS transport protein, beta-1, 3-N-acetylglucosamine transferase and beta-1, 4-galactosyl transferase is carried out; and (2) over-expression of a galactoside osmose enzyme and a UDP-galactose-4-epimerase is carried out. According to the genetically engineered bacterium disclosed by the invention, the MFS transporter, the beta-1, 3-N-acetylglucosamine transferase and the beta-1, 4-galactosyl transferase are exogenously introduced, and the expression quantity of galactosidase and UDP-galactose-4-epimerase in a genome is enhanced, so that the residual quantity of LNT II in an LNnT synthesis route can be effectively reduced, and the fermentation yield of the LNnT is increased.

The invention belongs to the technical field of dairy product processing, and discloses camel milk composite nutrition powder beneficial to bone health, the camel milk composite nutrition powder is composed of the following raw materials by weight: 70%-75% of whole camel milk powder, 5%-15% of whey protein, 5%-20% of isomaltooligosacharide, 1%-10% of inulin, 0.02%-8% of milk mineral salt, 0.02%-5% of hydrolyzed yolk powder, and the balance water. The oral liquid is prepared from the following components in percentage by weight: 0.01%-0.5% of colostrum basic protein, 0.01%-1% of cartilage powder containing type II collagen, 0.01%-0.1% of N-acetylglucosamine, 0.01%-0.02% of sodium hyaluronate, 0.05%-5% of collagen peptide and 0.01%-1% of liquorice extract. According to the invention, a multi-dimensional health system is constructed by scientifically compounding a plurality of key components: milk mineral salt, colostrum basic protein and hydrolyzed egg yolk powder synergistically promote bone mineral density increase and bone metabolism balance; the II-type collagen cartilage powder, the N-acetylglucosamine and the sodium hyaluronate are combined to realize joint protection and skin repair; the six vitamins and the four minerals can accurately regulate and control the nutrition metabolism of the middle-aged and elderly people, especially can strengthen calcium absorption and oxidation resistance, and can significantly improve the bone health and improve the skin state.

The invention provides mangrove chitin bacillus FCG-7 and application of the mangrove chitin bacillus FCG-7 in preparation of N-acetylglucosamine, and belongs to the technical field of microorganisms, the mangrove chitin bacillus FCG-7 provided by the invention is preserved in Guangdong Microbial Culture Collection Center, and the preservation number is GDMCC No: 63488. The strain provided by the invention has good low-temperature resistance and extracellular chitinase production capability, and can efficiently degrade chitin under a low-temperature condition to produce N-acetylglucosamine with an excellent biological effect; and the strain is still stable after passage, and is expected to be applied to the production of high-added-value N-acetylglucosamine by using chitin biomass as a raw material under a low-temperature condition.

The invention relates to the technical field of functional food, in particular to immune regulation type prebiotic syrup with synergy of galactomannan. The active components of the composite solid beverage are prepared from the following raw materials in percentage by weight: 20%-35% of fructo-oligosaccharide, 10%-18% of galactooligosaccharide, 8%-15% of stachyose, 3%-7% of xylooligosaccharide, 5%-12% of lactitol, 5%-10% of galactomannan, 2%-5% of yeast beta-glucan and 1%-3% of N-acetylglucosamine. The composition further comprises 4-8% of inulin and 3-6% of resistant dextrin as a matrix filling and slow-release carrier, and the sum of the weight percentages of all the active ingredients and the carrier is 100%. By remodeling intestinal microecology and inhibiting inflammation pathways, the intestinal inflammation state can be remarkably improved, expression of intestinal mucosa tight junction protein is promoted, and an innovative solution is provided for people suffering from chronic bowel diseases and immune imbalance.

The invention provides a cordyceps militaris mycelium and a preparation method and application thereof, and relates to the technical field of biological materials. According to the invention, chitinase is added into the cordyceps militaris mycelium material to carry out enzymolysis on chitin to obtain chitooligosaccharide and N-acetylglucosamine, so that beta-glucan in a mycelium framework is dissolved out, and the grafting efficiency of the cordyceps militaris mycelium material is improved; furthermore, the antibacterial effect of the antibacterial material is improved by carrying out grafting reaction on the cordyceps militaris mycelium material and an exogenous monomer antibacterial peptide which has antibacterial performance and contains carboxyl groups.

The invention discloses recombinant escherichia coli with high yield of N-acetylneuraminic acid and application of the recombinant escherichia coli, and relates to the technical field of biological genetic engineering. The invention relates to a recombinant escherichia coli, which is characterized in that the escherichia coli is taken as a host, and free expression of an N-acetylmannosamine epimerase gene yihS from Streptomyces xiamenensis or an N-acetylmannosamine epimerase gene ce3 from Bacteroides polymorpha and an exogenous N-acetylneuraminic acid lyase gene nano A is carried out; and carrying out recombinant expression on N-acetyl hexosamine 1-kinase nahK, a UDP-N-acetyl glucosamine pyrophosphorylase gene glmU and a UDP-N-acetyl glucosamine-2-epimerase gene neuC in the other synthetic route of the ManNAc. According to the recombinant escherichia coli with high yield of N-acetylneuraminic acid, the yield of N-acetylneuraminic acid can reach 23.08 g / L under a shake flask fermentation condition; a two-stage batch feeding strategy is adopted, the yield of N-acetylneuraminic acid in a 5L fermentation tank reaches 71.25 g / L, the molar conversion rate of GlcNAc reaches up to 57.60%, and the method has the potential of industrial application.

The invention discloses an engineered glycosyl transferase and application thereof in efficient preparation of triterpenoid saponin. The engineered glycosyl transferase is obtained by mutating serine at the 15th site of UGT74AC1 enzyme into alanine, mutating histidine at the 47th site into aspartic acid, mutating leucine at the 48th site into valine, mutating alanine at the 180th site into serine, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid, mutating histidine at the 180th site into aspartic acid The mutant is obtained by mutating serine at the 332 site into proline, phenylalanine at the 367 site into tryptophan and lysine at the 420 site into arginine. According to the invention, the glycosyl transferase with high catalytic activity is obtained by modifying an enzyme engineering technology, and good application of the glycosyl transferase in synthesis of triterpenoid saponin is realized. The glycosyl transferase disclosed by the invention can also be coupled with sucrose synthase, or coupled with N-acetylhexosamine kinase and N-acetylglucosamine-1-uridine phosphate transferase, and acetylglucosamine is used as a glycosyl donor, so that cascade production of triterpenoid saponin with lower cost and higher efficiency is realized.

The invention discloses an application of a composition of L-arginine and L-histidine in improving the yield of N-acetylglucosamine produced by microbial fermentation. The invention also discloses a culture medium for fermentation production of N-acetylglucosamine. The culture medium comprises a basic culture medium and a fed-batch culture medium, wherein the fed culture medium is prepared from the following components: 600 to 800 g / L of glucose, 4 to 6 g / L of monopotassium phosphate, 80 to 120 g / L of glycerol, 0.8 to 1.5 g / L of L-arginine and 0.8 to 1.5 g / L of L-histidine. According to the method, L-arginine and L-histidine with specific concentrations are added in the microbial fermentation process for producing N-acetylglucosamine, so that the yield of N-acetylglucosamine can be remarkably increased.

The invention provides a pharmaceutical composition for bone joints as well as a preparation method and application of the pharmaceutical composition. The pharmaceutical composition is prepared from the following components in parts by weight: 20 to 2000 parts of N-acetylglucosamine and 10 to 1000 parts of non-denatured type II collagen. In the compound composition of the N-acetylglucosamine and the non-denatured type II collagen, the two core components play a complementary role: the N-acetylglucosamine is focused on promoting synthesis of a cartilage matrix and provides a material basis for cartilage repair; the non-denatured type II collagen reduces damage of autoimmune response to cartilage through immunoregulation, the non-denatured type II collagen and the non-denatured type II collagen have a synergistic effect, the symptoms such as arthralgia and swelling can be relieved, the joint structure can be improved from the double angles of repairing and protecting, and particularly the treatment effect on patients with severe osteoarthritis is remarkably superior to that of a single-component preparation; and an innovative and efficient choice is provided for the treatment of osteoarticular diseases.

The invention provides a nutrition enhancer beneficial to bone health of middle-aged and elderly people, a preparation method of the nutrition enhancer and application of the nutrition enhancer in preparation of medial care food, and belongs to the field of nutritious food. The nutrient supplement comprises a plant fermentation product, osteopontin peptide, collagen peptide, N-acetylglucosamine and calcium, vitamins and mineral substances can be added, and the plant fermentation product is obtained by performing anaerobic fermentation on rhizoma drynariae and chestnuts through a complex microbial inoculant composed of lactobacillus reuteri and bifidobacterium longum subsp. Longum; the collagen peptide is prepared by performing enzymolysis on bovine bones through alkaline protease and flavourzyme; the hydrogel is prepared by adopting a sodium alginate-calcium chloride-carboxymethyl chitosan micro-capsule embedding process. An in-vitro experiment shows that the nutrition enhancer can remarkably promote osteoblast proliferation, differentiation and mineralization; animal experiments show that the bone mineral density of osteoporosis model mice can be effectively improved. The nutrition enhancer disclosed by the invention is suitable for preparing care food and bone health products, and has a remarkable effect of improving bone health of middle-aged and elderly people.

The invention discloses an N-acetylglucosamine transferase AcetRS-K23G and an application thereof, and belongs to the technical field of functional enzymes. And the amino acid sequence of the N-acetylglucosamine transferase AcetRS-K23G is as shown in SEQ ID NO. 3. The invention further discloses an application of the N-acetylglucosamine transferase AcetRS-K23G in the preparation of the chitosan oligosaccharide. The N-acetylglucosamine transferase AcetRS-K23G disclosed by the invention is obtained by performing mutation modification on the N-acetylglucosamine transferase AcetRS, and can be used for producing the chitosan oligosaccharide with the polymerization degree of 5-7, especially the heptaose, the yield of the heptaose can reach 42.01 mg / L, and the N-acetylglucosamine transferase AcetRS-K23G is an ideal functional enzyme for industrially producing the heptaose. The product spectrum of the N-acetylglucosamine transferase is widened, and the N-acetylglucosamine transferase can be used for preparing high-polymerization-degree chitosan oligosaccharide and has a wide application prospect.

The present invention relates to antibody conjugates which are particularly suitable for targeting cells expressing PTK7, in particular tumor cells. An antibody conjugate according to the present invention has structure (1): AB-[(L6) b-{Z-L-D} x] y (1) wherein AB is an antibody capable of targeting a tumor expressing PTK7; l is a joint connecting Z to D; z is a linking group; l6 is-GlcNAc (Fuc) w-(G) j-S-(L7) w '-wherein G is a monosaccharide, j is an integer in the range of 0 to 10, S is a sugar or a sugar derivative, GlcNAc is N-acetylglucosamine, and Fuc is fucose, w is 0 or 1, w' is 0, 1 or 2, and L7 is-N (H) C (O) CH2-,-N (H) C (O) CF2-or-CH2-; d is selected from the group consisting of an anthracycline, a camptothecin, a tubulysin, an endiyne, an amanitine, a duocarmycin, a maytansinoid, an aurestatin, eribulin, a BCL-XL inhibitor, a miscanthus semiaquilaria, a KSP inhibitor, a TLR agonist, an indolo-benzodiazepine dimer or a pyrrolo-benzodiazepine dimer (PBD), and an analog or prodrug thereof; b is 0 or 1; x is 1 or 2; and y is 1, 2, 3 or 4. The invention further relates to a method for preparing said antibody conjugate of structure (1) and to the use of said antibody conjugate of structure (1).

The invention belongs to the field of synthetic biology and metabolic engineering, and particularly relates to high-yield sialyl acyl-N-tetrasaccharide a escherichia coli as well as a construction method and application thereof. According to the method, recombinant escherichia coli is taken as an initial strain, and a beta1, 3-galactosyl transferase gene wbgO from escherichia coli O55: H7 is integrated into a chromosome in a multi-copy form, so that a lactyl-N-tetrasaccharide efficient synthesis chassis strain without plasmid dependence is constructed. And overexpression neuC, neuB, neuA and Nm3ST are introduced through plasmids, so that the supply of glycosyl donors is improved. The expression intensity of uridine diphosphate-N-acetylglucosamine synthesis pathway genes glmM and glmUS is regulated through ribosome binding site engineering, and a cytidine triphosphate regeneration module is introduced, so that the yield of sialyloyl-N-tetrasaccharide a is increased. And finally, the maximum titers of the sialyloyl-N-tetrasaccharide a respectively reach 2.238 g / L and 8.178 g / L by shaking a flask and culturing in batches. The invention provides an efficient technical scheme for industrial production of complex breast milk oligosaccharide.

The invention discloses a CgGlmS mutant and application of the CgGlmS mutant in synthesis of N-acetylglucosamine (GlcNAc) from corynebacterium glutamicum, and belongs to the technical field of biology. According to the invention, a bottleneck enzyme CgGlmS in a synthetic route of N-acetylglucosamine is subjected to deep rational analysis and semi-rational transformation. Through systematic research on the structure and function of an original CgGlmS enzyme from corynebacterium glutamicum S9114, the efficient CgGlmS mutant A253M is successfully screened out, and the enzyme activity, stability and catalytic efficiency of the mutant are obviously improved compared with those of a wild type. The mutant CgGlmS is overexpressed in corynebacterium glutamicum S9114 by using plasmids, so that the yield of N-acetylglucosamine in corynebacterium glutamicum is increased. The CgGlmS enzyme is directionally modified, so that the catalytic efficiency of the CgGlmS enzyme is improved, accumulation of N-acetylglucosamine in corynebacterium glutamicum is further promoted, and powerful support is provided for efficient production of the corynebacterium glutamicum.

The invention provides a coupling drug and a preparation method thereof, and relates to the field of antibody drugs. The structure of the coupling drug provided by the invention is as shown in the following formula I, X is an antibody or fusion protein containing an Fc fragment, GlcNAc is N-acetylglucosamine, Man is mannose, Fuc is fucose, Gal is galactose, Fucc * is a fucose derivative and contains Dxd; and m is 1-4. Compared with DS-8201, the antibody coupling drug prepared by the invention has better hydrophilicity, stability and plasma stability. # imgabs0 #

The invention discloses an engineering bacterium for improving the yield of N-acetylglucosamine, which is characterized in that an H1-6 strain is taken as a starting strain, and one or more of the following genes in the genome of the H1-6 strain are knocked out: gatY, ibaG, bfr, pfkA, wecC, pdxB, rfe, gntT, acrA, proV, proW, ygaZ, treB, pck and ycW; wherein the strain H1-6 is prepared according to a method in the document: DOI (Document Object Institute): 10.1089 / crispr. 2021.0018, and the strain H1-6 is prepared according to a method disclosed by the invention. The invention also discloses a preparation method of the engineering bacterium and application of the engineering bacterium in production of N-acetylglucosamine. According to the invention, a plurality of high-yield NAG genetically engineered bacteria are obtained through the MUCICAT system, a method for efficiently obtaining high-yield target strains is provided, and the method is expected to be widely applied to the construction of synthetic biological chassis cells.

The invention relates to the fields of enzyme engineering and microbial fermentation production, in particular to an N-acetylglutamate synthetase mutant for producing N-acetyl blue and application of the N-acetylglutamate synthetase mutant. According to the invention, the N-acetylglutamate synthetase mutant EcargAV323A / S435A is constructed by researching the structure of N-acetylglutamate synthetase ArgA (EcargA) from Escherichia coli and mutating the 323rd site and the 435th site of EcargA protein in combination with a directed evolution technology, so that the N-acetylglutamate synthetase mutant EcargAV323A / S435A is constructed. When the engineering strain of the N-acetylglutamate synthetase mutant is used for producing the N-acetylobservation blue through fermentation, the yield of the N-acetylobservation blue can be remarkably improved, the generation of a by-product observation blue is reduced, the fermentation process is simplified, and the production cost is reduced. The N-acetylglutamate synthetase mutant and the engineering strain provided by the invention have good industrial application value.

The present disclosure provides a combination comprising an antibody that specifically binds to C5 and a C5 iRNA, which is a glycoconjugate containing a ligand with a terminal N-acetylgalactosamine (GalNAc) residue and / or N-acetylglucosamine (GlcNAc) residue. A method for reducing degradation of glycoconjugate RNA by the beta-hexosaminidase enzyme is also provided. The present disclosure also includes a method for treating or preventing a C5-related disease or disorder by administering one or more doses of an anti-C5 antibody or antigen-binding fragment thereof in combination with one or more doses of a C5 iRNA; preferably, the anti-C5 antibody or fragment and the C5 iRNA are in a combination. The present disclosure also includes a dosing regimen for treating a C5-related disease or disorder with a combination of an anti-C5 antibody and a C5 iRNA in either a treatment-naive subject or a subject switching from a previous C5 inhibitor therapy.