77 results about "Sialyltransferase" patented technology

Disclosed are immortalized human embryonic retina cells, having a nucleic acid sequence encoding an adenoviral E1A protein integrated into the genome of the cells, and further comprising a nucleic acid sequence encoding an enzyme involved in post-translational modification of proteins, such as a sialyltransferase, wherein said nucleic acid sequence encoding the enzyme involved in post-translational modification of proteins is under control of a heterologous promoter. Methods for producing recombinant proteins from such cells and obtaining such recombinant proteins having increased sialylation are provided as are novel compositions of isoforms of erythropoietin .

The present invention relates to eukaryotic host cells which have been modified to produce sialylated glycoproteins by the heterologous expression of a set of glycosyltransferases, including sialyltransferase and/or trans-sialidase, to become host-strains for the production of mammalian, e.g., human therapeutic glycoproteins. Novel eukaryotic host cells expressing a CMP-sialic acid biosynthetic pathway for the production of sialylated glycoproteins are also provided. The invention provides nucleic acid molecules and combinatorial libraries which can be used to successfully target and express mammalian enzymatic activities (such as those involved in sialylation) to intracellular compartments in a eukaryotic host cell. The process provides an engineered host cell which can be used to express and target any desirable gene(s) involved in glycosylation.

This invention provides labeled-substrate conjugates for assaying enzymes, particularly neuraminidases. Also provided are assays that are useful for identifying compounds that inhibit sialyltransferases or neuraminidases and may be useful in treating subjects with influenza. In particular, the present invention relates to methods of using such labeled substrate conjugates to screen for enzyme inhibitors, particularly in a high-throughput format.

This invention provides methods and compositions for treating and preventing atherosclerosis other undesired blood clotting. The methods for treating and preventing atherosclerosis and related conditions involve administering to a mammal an agent that reduces activity of an ST3Gal IV sialyltransferase, which results in enhanced clearance of von Willebrand Factor (vWF) from the mammal.

Provided herein are a methods of reducing a level of activity of a sialyl transferase enzyme, a sialidase enzyme or a combination thereof using inhibitors of these enzymes, for example specific inhibitory compound or antibodies directed against the enzymes. The methods are effective to treat an inflammatory disease or disorder or a primary or metastatic cancer. Also provided is a method for screening potential inhibitors of sialyl transferase enzymes.

The invention discloses a synthetic method of synthesizing double-sialylated tetrasaccharide by a chemically controllable enzyme method. The invention further provides two intermediates, which are used for synthesizing and preparing the double-sialylated tetrasaccharide, are compounds respectively as shown in formulas IV and V. According to the synthetic method disclosed by the invention, the flexibility of a chemical synthetic method and the high-area selectivity and high efficiency of the enzyme synthetic method are combined together, so that synthesis of the double-sialylated tetrasaccharide by using a chemical intervention method is firstly realized, defects such as low substrate reaction activity, multiple synthetic steps and low yield facing in existing chemical synthesis of the double-sialylated tetrasaccharide are solved, as well as a problem that sialyl transferase is difficult to obtain and only glycopeptides is identified in the enzyme method is solved; the synthetic method disclosed by the invention has the advantages of high substrate reaction activity and high yield, and therefore, the synthetic method has important significance in researching biological functions of sialic acid glucoside on molecular level and developing carbohydrate drugs based on the biological functions.

The present invention provides modified Campylobacter sialyltransferase proteins that exhibit enhanced expression as compared to its unmodified form. Nucleic acids that encode the sialyltransferase proteins are also included, as are methods to produce and use the sialyltransferase proteins.

The invention discloses a method for preparing sialyllactose, and relates to the technical field of preparation of sialyllactose. The method for preparing sialyllactose disclosed by the invention comprises the steps of adding kinase to a reaction system containing a substrate, and performing an enzyme catalysis reaction to prepare the sialyllactose, wherein the kinase comprises CMP kinase, polyphosphate sialic acid synthase and sialytransferase; and the substrate comprises CMP, polyphosphate, sialic acid and lactose. The method adopts various kinase namely the CMP kinase, the polyphosphate kinase, the CMP-sialic acid synthetase and sialytransferase to catalyze the corresponding substrate to prepare the sialyllactose. The method has the characteristics of being high in yield, low in cost, short in cycle and the like.

The invention discloses a preparation method of sialyl enteromorpha oligosaccharide promoting intestinal probiotics proliferation. Enteromorpha is dried and subjected to superfine grinding, and by means of an ethanol reflux extraction technology, the dried and degreased enteromorpha powder is obtained; the enteromorpha oligosaccharide is obtained through microwave-assisted extraction, deproteinization and polysaccharide and pigment removing; sialyltransferase is added into a reaction system containing enteromorpha oligosaccharide, a glycosylation reaction is conducted, and the sialyl enteromorpha oligosaccharide is prepared. The oligosaccharide can significantly increase the number of intestinal probiotics and can be used for preparing drugs or health-care products which improve intestinal flora.

The present disclosure relates to a method for preparing recombinant glycoproteins with high sialic acid content. More specifically, for UDP-GlcNAc 2-epimerase/ManNAc kinase (GNE/MNK) enzyme where point mutation was induced by substituting arginine at position 263 by leucine only or by further substituting arginine at position 266 by glutamine, epimerase activity is constantly maintained, and overexpressed cells thereof experience an increase in intracellular cytidine monophosphate (CMP)-sialic acid content, irrespective of CMP-sialic acid concentration.,Particularly, since in an glycoprotein(such as, erythropoietin and thrombopoietin)-producing host cell where point mutationinduced GNE/MNK, human alpha-2,3-sialyltransferase and a CMP-sialic acid transporter gene are simultaneously overexpressed, intracellular content of CMP-sialic acid and sialic acid in glycoprotein increases in cells, overexpression in a host cell producing a sialylated recombinant glycoprotein the three genes above may be useful for preparing glycoprotein with increased sialic acid content.

The present invention provides a novel β-galactoside-α2,6-sialyltransferase having high productivity and/or high activity, and a nucleic acid encoding the sialyltransferase. The present invention also provides a microorganism producing the sialyltransferase. The present invention further provides a vector carrying a nucleic acid encoding the sialyltransferase, and a host cell transformed with the vector, as well as a method for producing a recombinant β-galactoside-α2,6-sialyltransferase.

Disclosed are methods for the fermentative production of a sialylated saccharide and genetically engineered microbial cells for use in said method, wherein the genetically engineered microbial cells comprise (i) a sialic acid biosynthesis pathway comprising a glucosamine-6-phosphate N-acetyltransferase, (ii) a cytidine 5'-monophospho- (CMP)-N- acetylneuraminic acid synthetase; and (iii) a sialyltransferase, for producing sialylated saccharides, as well as the use of said sialylated oligosaccharides for providing nutritional compositions.

The invention relates to poly-sialyltransferse polypeptides with enhanced solubility and activity and methods of using the poly-sialyltransferases for production of poly-sialylated end products, e.g., oligosaccharides, glycoproteins and glycolipids.

The invention discloses a method for synthesizing sialylated oligosaccharide and an analogue. The invention provides the method for synthesizing sialylated oligosaccharide and the analogue, the method comprises the followings steps: 1)uniformly mixing a donor compound, MgC12, pyruvate and an engineering bacteria E.coli delta nanTEK/pNA bacterium suspension, reacting, collecting a supernatant; 2)adding an acceptor compound, cytidine triphosphate, CMP-sialic acid synthetase and sialytransferase in the supernatant, uniformly mixing, reacting, and collecting the reaction product which is sialyloligosaccharide or its analogue. The experiment of the present invention proves that the method has the advantages that N-acetylneuraminic acid with low price is taken as a raw material, a method of whole-cell catalysis and a method of two-step enzymatic synthesis are combined, the sialyloligosaccharide and its analogue can be synthesized by an one-pot synthesis method, the synthesis cost of the compounds is greatly reduced, the synthesis process is simple, and the separation method is simple.