Process for mono- and bi-sialylation of glycoproteins using beta-galactoside alpha-2,6-sialyltransferase mutants truncated at the N-terminus

摘要

The present disclosure is directed to the use of certain glycosyltransferase variants with N-terminal truncation deletions. It was found that the combination of two different truncation mutants of human β-galactoside-α-2,6-sialyltransferase I (hST6Gal-I) exhibits different specific sialyltransferase enzyme activities. In one example, the second mutant Δ108 hST6Gal-I was mono-sialylated target molecule under conditions where the first mutant Δ89 hST6Gal-I catalyzed the formation of a bi-sialylated target molecule. The formation of was catalyzed. Thus, it encodes a variant of a mammalian glycosyltransferase to sialylate the terminal acceptor group of a glycan moiety that is part of a glycoprotein, such as an immunoglobulin, in a particularly quantitatively controlled manner. Nucleic acids, methods and means for recombinantly producing mammalian glycosyltransferase variants and uses thereof are disclosed. [Selection] Figure 3