178 results about "Acetylglucosamine" patented technology

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 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 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.

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 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 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 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 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.

The present application relates to the technical field of medicine, and provides a kind of haena polysaccharide and its preparation method and application and target endogenous coagulation pathway anticoagulant and / or antithrombotic drug.The haena polysaccharide provided by the present application is fucosylated chondroitin sulfate polysaccharide, the weight average molecular weight is 9-13 million, the molar ratio of glucuronic acid, N-acetylglucosamine and fucose is 1:0.8-1.2:0.5-0.8, and the mass percentage content of sulfate group is 25-40%.The haena polysaccharide provided by the present application can target endogenous coagulation pathway terminal rate-limiting enzyme (iFXase), and has no obvious effect on coagulation factors in other coagulation pathways, realizes the effect of anticoagulation and non-hemorrhage, and can be widely applied in acute and recovery period treatment of ischemic stroke, solves the safety problem of using anticoagulant and antithrombotic drug for clinical ischemic stroke patients, and opens up a new field of research and development of target endogenous coagulation pathway rate-limiting enzyme anticoagulant drug.

The present invention discloses a Sepia esculenta ink polysaccharide for improving high-glucose damage of endothelial cells, and a preparation method and application thereof. The Sepia esculenta ink polysaccharide has a polysaccharide backbone composed of fucose, galactosamine, mannose, and N-acetylglucosamine, and has a glucuronic acid branch chain at the C-3 position of mannose. It is an aminopolysaccharide with a weight-average molecular weight of 10-16 kDa and a sulfation degree of 8%-15%. Through experimental verification, compared with similar compounds, the Sepia esculenta ink polysaccharide can effectively improve the state of endothelial cells and maintain the normal filtration function of vascular endothelium. At the same time, the risk of bleeding side effects of the Sepia esculenta ink polysaccharide is significantly lower than that of similar polysaccharides, and it has higher safety in use. Furthermore, the Sepia esculenta ink polysaccharide can be used to develop adjuvant therapeutic drugs for late-stage diabetic lesions, filling the gap in such products on the current market.

The invention discloses a nano vesicle with tissue targeting and mitochondrial localization as well as preparation and application of the nano vesicle. The nano-vesicle is a nucleus pulposus cell membrane entrapped with a small molecule mitochondrial membrane stabilizer, and tetra-acetylated N-acetamido mannose is added in the culture process of nucleus pulposus cells, so that a sialic acid derivative with an azide group is expressed on the surface of the nucleus pulposus cell membrane. Therefore, triphenylphosphine cations are modified on the surface of the nucleus pulposus cell membrane through a biological orthogonal reaction. The nano-vesicle can stabilize a mitochondrial membrane structure, improve cell aging-related secretion phenotype release and mitochondrial functions, block mtDNA release and SASP factor generation, realize anti-aging, anti-inflammatory and tissue degeneration intervention, can be used for preparing intervention drugs for tissue degeneration diseases related to mitochondrial membrane damage, and has broad application prospects. Or a drug for regulating mtDNA leakage and SASP release in a cell aging model. Wide application prospects and important clinical transformation values are realized.

The invention belongs to the technical field of biological enzyme engineering, and particularly relates to a glucosamine-6-phosphate synthetase mutant and application thereof. A plurality of glucosamine-6-phosphate synthase mutants capable of remarkably improving the yield of N-acetylglucosamine are screened by performing single-point mutation or combined mutation on amino acid residues near a substrate binding pocket of the glucosamine-6-phosphate synthase or on the surface of protein of the glucosamine-6-phosphate synthase. According to the technical scheme, a foundation is laid for producing glucosamine by further transforming escherichia coli through metabolic engineering.

The present invention discloses a spatially separated orthogonal translation system and its application. In order to enhance the specific translational expression of target genes in microbial hosts and reduce the mis-translation of background genes, the present invention provides a spatially separated orthogonal translation system. Specifically, first, the codons of the target gene are replaced with the TAG stop codon. Secondly, RTBA and thrombin F2 are selected as the mRNA-protein interaction system. Then, TyrRS / tRNA is heterologously expressed. This system can incorporate O-methyl-L-tyrosine into the amber stop codon UAG, and further fuse and express TyrRS and F2 with disordered proteins respectively. Finally, the translational selectivity of the target gene is increased to 4.01-fold. Finally, the N-acetylglucosamine epimerase AGE is modified to obtain a mutant AGE OMeY , whose specificity constant k cat / K m is increased by 86.0% compared with the wild type, and further, the specific translational expression of AGE OMeY is achieved in Bacillus subtilis cells by using the optimal orthogonal translation system, and the yield of the target product is as high as 2.1 g / L.

The invention provides a method for treating autoimmune diseases mediated by regulatory T cell (Treg) programmed necrosis. Specifically, the invention provides application of an O-linked beta-N-acetylglucosamine glycosylation (O-GlcNAcylation) accelerant, and the O-linked beta-N-acetylglucosamine glycosylation accelerant is used for preparing a medicine or a preparation for treating programmed necrosis type autoimmune diseases. It is found for the first time that when the O-GlcNAcylation promoter is used for improving the O-GlcNAcylation level of RIPK1 / 3 protein, Treg programmed necrosis can be effectively inhibited, and therefore autoimmune diseases are improved.

This disclosure is in the technical field of synthetic biology and metabolic engineering. More particularly, this disclosure is in the technical field of fermentation of metabolically engineered microorganisms. This disclosure describes engineered micro-organisms able to synthesize sialylated compounds via an intracellular biosynthesis route. These micro-organisms can dephosphorylate N-acetylglucosamine-6-phosphate to N-acetyl glucosamine and convert the N-acetylglucosamine to N-acetylmannosamine. These micro-organisms also have the ability to convert N-acetylmannosamine to N-acetyl-neuraminate. Furthermore, this disclosure provides a method for the large scale in vivo synthesis of sialylated compounds, by culturing a microorganism in a culture medium, optionally comprising an exogenous precursor such as, but not limited to lactose, lactoNbiose, N-acetyllactosamine and / or an aglycon, wherein the microorganism intracellularly dephosphorylates N-acetylglucosamine-6-phosphate to N-acetylglucosamine, converts N-acetyl-glucosamine to N-acetylmannosamine and convert the latter further to N-acetyl-neuraminate.

The invention discloses a genetically engineered bacterium for producing heparinogen and a construction method and application thereof, the genetically engineered bacterium takes Escherichia coli Nissle 1917 as a chassis bacterium, and the construction method comprises the following steps: (1) knocking out endonuclease I coding gene endA in a chassis bacterium genome; (2) knocking out a 6-phosphofructokinase I coding gene pfkA in a chassis bacterium genome; (3) carrying out overexpression on a 6-phosphoglucosamine synthetase encoding gene glmS and / or a UDP-glucose-6-dehydrogenase encoding gene kfiD from a chassis bacterium genome; (4) removing the feedback inhibition of the 6-phosphate glucosamine on the GlmS so as to promote the synthesis of UDP-N-acetylglucosamine; and (5) knocking out the 6-phosphate glucosamine deaminase coding gene nagB in the chassis bacterium genome. The engineering strain obtained by the invention can more efficiently synthesize the proheparin, the shake flask titer reaches 397.9 mg / L, which is increased by about 3 times compared with a wild strain, and the engineering strain has certain industrial application value.

The present application belongs to the field of genetic engineering and microbial fermentation technology, and particularly relates to a recombinant Escherichia coli for producing N-acetylglucosamine as well as a construction method and application thereof. The present application takes Escherichia coli as a chassis, knocks out the nagDCABE gene cluster, the manXYZ gene cluster and the serA gene of the genome of the Escherichia coli, and introduces the glmS, GNA1 and serA genes into the Escherichia coli through a vector for expression. The yield of the Escherichia coli for fermenting GlcNAc provided by the present application can reach more than 100 g / L.

The present application relates to a kind of targeting bacterial UDP-N-acetylglucosamine enolpyruvate transaminase antibacterial compound and its application, the antibacterial compound is S-(4-chlorobenzyl) chloro isothiourea, its chemical structure is as shown in formula I: I;Or its pharmaceutically acceptable salt, stereoisomer, solvate, crystal form, isotopically labeled or prodrug.The antibacterial compound of the present application can effectively inhibit the growth of klebsiella pneumoniae, including carbapenem-resistant klebsiella pneumoniae and high virulence klebsiella pneumoniae;It also has good bacteriostatic effect on escherichia coli and pseudomonas aeruginosa;It is expected to be applied to the clinical treatment of infection caused by drug-resistant klebsiella pneumoniae and high virulence klebsiella pneumoniae and other pathogenic bacteria, and has important clinical significance and social benefits.

The invention discloses a method for producing oligosaccharide by cooperatively treating aspergillus niger residues through multiple enzymes. The method comprises the following steps: mixing pretreated aspergillus niger residues with hydrochloric acid, carrying out acidolysis wall breaking, and carrying out suction filtration on an obtained wall-broken mixture; carrying out mixed treatment on filtrate obtained by suction filtration with cellulase and beta-glucanase, filtering, and carrying out concentration and alcohol precipitation on supernate to obtain soluble beta-glucan oligosaccharide; performing filter residue enzymolysis on filter residues obtained by suction filtration by using mesoporous silica immobilized chitinase, and recovering the immobilized chitinase after enzymolysis; and filtering the mixed solution subjected to enzymolysis by using the immobilized chitinase, and carrying out alcohol precipitation on the supernate to obtain the N-acetylglucosamine and the chitosan oligosaccharide. According to the method disclosed by the invention, the aspergillus niger residues are jointly treated by adopting multiple enzymes, the yield of N-acetylglucosamine and chitosan oligosaccharide reaches 85.1%-88.5%, and the yield of beta-glucosamine oligosaccharide reaches 86.7%-89.3%. The invention provides a brand new route for producing various oligosaccharides by utilizing solid waste aspergillus niger residues in the fermentation industry.

The present invention provides a copolymer which has a hydrophobic constituent unit (a), wherein the polymer terminal is a structure (T) containing a trithiocarbonate structure and a C8-15 hydrocarbon group. The present invention also provides a copolymer which has a constituent unit (b) containing an N-acetylglucosamine group, wherein the polymer terminal is a structure (T) containing a trithiocarbonate structure and a C8-15 hydrocarbon group.

A method for producing modified cells lacking mannosyl(alpha-1,3)-glycoprotein beta-1,2-N-acetylglucosamine transferase 1 ("MGAT1") activity is provided. The MGAT1 activity-deficient CHO cell line produced by this method is also provided. A method for producing glycoproteins is further disclosed.

The invention relates to the technical field of biology, and particularly discloses a composition and application thereof in improving articular cartilage health. The composition comprises sodium hyaluronate, colostrum basic protein and N-acetylglucosamine, wherein the mass ratio of the sodium hyaluronate to the colostrum basic protein to the N-acetylglucosamine is (1-2): (1-2): (1-8). The composition disclosed by the invention can be used for increasing the bone mineral density, increasing the number of osteoblasts, promoting cartilage growth and increasing the content of II-type collagen in an animal body, so that the bone joint function can be effectively improved, and a new method is provided for joint maintenance.