Sialyltransferase
Sialyltransferases are enzymes that transfer sialic acid to nascent oligosaccharide.Each sialyltransferase is specific for a particular sugar substrate. Sialyltransferases add sialic acid to the terminal portions of the sialylated glycolipids (gangliosides) or to the N- or O-linked sugar chains of glycoproteins.