79 results about "Sialyltransferase" patented technology

The present invention relates to a method for the large scale in vivo synthesis of sialylated oligosaccharides, culturing a microorganism in a culture medium, optionally comprising an exogenous precursor such as lactose, wherein said microorganism comprises heterologous genes encoding a CMP-Neu5Ac synthetase, a sialic acid synthase, a GlcNAc-6-phosphate 2 epimerase and a sialyltransferase, and wherein the endogenous genes coding for sialic acid aldolase (NanA) and for ManNac kinase (NanK) have been deleted or inactivated. The invention also relates to these micoorganisms which are capable of producing internally activated sialic acid.

The invention relates to a fusion protein comprising a bifunctional sialytransferase and a poly-sialytransferase and methods to use the fusion proteins for production of poly-sialylated end products, e.g. oligosaccharides and glycoproteins.

The present invention provides an extremely useful and novel β-galactoside-α2,6-sialyltransferase having an optimum reaction pH in a neutral to alkaline range, and a nucleic acid encoding 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.

The invention provides compositions comprising one or more isoforms of an erythropoietin (EPO) comprising glycans linked thereto, characterized in that said glycans comprise LewisX structures and on average at least 6 sialic acid moieties per EPO molecule. The invention further provides methods for obtaining a composition comprising one or more isoforms of an erythropoietin (EPO) comprising glycans linked thereto wherein said glycans comprise on average at least 6 sialic acids per EPO molecule and from 0 to 2 Lewis x structures, said method comprising: a) providing a eukaryotic cell containing a nucleic acid sequence encoding an adenoviral E1A protein in expressible format and further containing a nucleic acid encoding an EPO in expressible format, wherein said cell further contains a nucleic acid sequence encoding a sialyltransferase, preferably an alpha-2,6-sialyltransferase or an alpha-2,3-sialyltransferase, under control of a heterologous promoter; b) culturing said cell in a serum-free culture medium and allow expression of an EPO in said cell; c) harvesting the expressed EPO from said cell and / or from the culture medium; and d) purifying and fractionating the EPO to obtain fractions which have an increased average sialic acid content of the N-linked glycans per EPO molecule, to obtain a composition comprising one or more iso forms of an EPO comprising glycans linked thereto wherein said glycans comprise on average at least 6 sialic acids per EPO molecule and from 0 to 2 Lewis x structures.

The present disclosure is directed to the use of certain glycosyltransferase variants having N-terminal truncation deletions. It was found that the combination of two different truncation variants of human β-galactoside-α-2,6-sialyltransferase I (hST6Gal-I) exhibited different specific sialyltransferase enzymatic activities. In one example, under conditions wherein the first variant Δ89 hST6Gal-I catalyzed formation of bi-sialylated target molecules the second variant Δ108 hST6Gal-I catalyzed formation of mono-sialylated target molecules. Thus, disclosed are variants of mammalian glycosyltransferase, nucleic acids encoding the same, methods and means for recombinantly producing the variants of mammalian glycosyltransferase and use thereof, particularly for sialylating in a quantitatively controlled manner terminal acceptor groups of glycan moieties being part of glycoproteins such as immunoglobulins.

Provided are compositions comprising one or more isoforms of an erythropoietin (“EPO”) comprising glycans linked thereto, wherein the glycans have Lewis x structures and on average at least six sialic acid moieties per EPO molecule. Further provided are methods for obtaining a composition comprising one or more isoforms of EPO comprising glycans linked thereto, wherein the glycans comprise on average at least six sialic acids per EPO molecule and from zero to two Lewis x structures, the method comprising: a) providing a eukaryotic cell containing a nucleic acid sequence encoding an adenoviral E1A protein in expressible format and a nucleic acid encoding EPO in expressible format, wherein the cell further contains a nucleic acid sequence encoding a sialyltransferase, e.g., an α-2,6-sialyltransferase or an α-2,3-sialyltransferase, under control of a heterologous promoter; b) culturing the cell in a serum-free culture medium and allowing expression of EPO in the cell; c) harvesting the expressed EPO from the cell and / or from the culture medium; and d) purifying and fractionating the EPO to obtain fractions that have an increased average sialic acid content of the N-linked glycans per EPO molecule, to obtain a composition comprising one or more isoforms of an EPO comprising glycans linked thereto, wherein the glycans comprise on average at least six sialic acids per EPO molecule and from zero to two Lewis x structures.