Beta-galactoside alpha-2,6-sialyltransferase 1

Description

• General description: Recombinant human Beta-galactoside alpha-2,6-sialyltransferase 1 (ST6Gal I) is expressed in human HEK 293 cells as a glycoprotein with a calculated molecular mass of 43.5 kDa (amino acids 27-406). The DTT-reduced protein migrates as a ~50 kDa polypeptide on SDS-PAGE due to glycosylation. This protein is manufactured in human cells, with no serum. The human cells expression system allows human-like glycosylation and folding, and often supports higher specific activity of the protein. The protein is produced with no artificial tags.
• Biochem/physiol Actions: ST6Gal I catalyzes the transfer of CMP-N-acetylneuraminate (CMP-sialic acid, CMP-NANA) to the β-D-galactosyl-1,4-N-acetyl-D-glucosaminyl termini on glycoproteins. Sialic acids are distributed in a variety of glycolipids and glycoproteins.1 The sialic acid that is added to a galactose (Gal) can be bound either to the hydroxyl attached to carbon-3 of Gal to form an α-2,3 glycosidic linkage, or to the hydroxyl group attached to carbon-6 to form an α-2,6 glycosidic linkage.1 ST6Gal I generates a α-2,6 linkage of sialic acid on the non-reducing, terminal Galβ1 4GlcNAc residues of oligosaccharides and glycoconjugates.2 Terminal sialylation has been shown to decrease Fcγ receptor binding and increase anti-inflammatory activity,3 as well as antibody-dependent cellular cytotoxicity in different studies by reduced binding of sialylated antibody towards FcγRIIIa.4-5 This recombinant ST6Gal I product can be used to study the mode of action of the enzyme, as well as its potential inhibitors. It can also be used as a glycoengineering tool to modify glycoproteins in vitro.CMP-N-acetylneuraminate (CMP-sialic acid, CMP-NANA) to the β-D-galactosyl-1,4-N-acetyl-D-glucosaminyl termini on glycoproteins.Sialic acids are distributed in a variety of glycolipids and glycoproteins. The sialic acid that is added to a galactose (Gal) can be bound either to the hydroxyl attached to carbon-3 of Gal to form an α-2,3 glycosidic linkage, or to the hydroxyl group attached to carbon-6 to form an α-2,6 glycosidic linkage. ST6Gal I generates a α-2,6 linkage of sialic acid on the non-reducing, terminal Galβ1 4GlcNAc residues of oligosaccharides and glycoconjugates. Terminal sialylation has been shown to decrease Fcγ receptor binding and increase anti-inflammatory activity, as well as antibody-dependent cellular cytotoxicity in different studies by reduced binding of sialylated antibody towards FcγRIIIa.
• Unit Definition: One unit is defined as the amount of enzyme required to transfer 1.0 nanomole of sialic acid from CMP-NANA to asialofetuin per minute at pH 6.0, 37oC.