Two N-terminally truncated variants of human β-galactoside α2,6 sialyltransferase I with distinct properties for in vitro protein glycosylation
| Autor: | Alfred Engel, Michael Greif, Rainer Mueller, Marco Thomann, Bernd Nidetzky, Christiane Luley-Goedl, Doris Ribitsch, Helmut Schwab, Sebastian Malik, Christine Jung, Harald Sobek, Katharina Schmoelzer |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Models
Molecular 0301 basic medicine Glycan Glycosylation medicine.drug_class Sialyltransferase Monoclonal antibody Biochemistry 03 medical and health sciences chemistry.chemical_compound Polysaccharides medicine Humans Cloning Molecular beta-D-Galactoside alpha 2-6-Sialyltransferase chemistry.chemical_classification biology Chemistry Antibodies Monoclonal Genetic Variation Biological activity Galactoside Sialyltransferases In vitro Sialic acid carbohydrates (lipids) HEK293 Cells 030104 developmental biology Enzyme biology.protein |
| Zdroj: | Glycobiology. 26:1097-1106 |
| ISSN: | 1460-2423 0959-6658 |
| DOI: | 10.1093/glycob/cww046 |
| Popis: | Sialic acid groups of protein N-glycans are important determinants of biological activity. Exposed at the end of the glycan chain, they are potential targets for glycan remodeling. Sialyltransferases (STs; EC 2.4.99) are the enzymes that catalyze the sialic acid transfer from a CMP-activated donor on to a carbohydrate acceptor in vivo. Recombinant expression of the full-length human β-galactoside α2,6 sialyltransferase I (ST6Gal-I) was hampered and therefore variants with truncated N-termini were investigated. We report on the distinct properties of two N-terminally truncated versions of ST6Gal-I, namely Δ89ST6Gal-I and Δ108ST6Gal-I, which were successfully expressed in human embryonic kidney cells. The different properties of these enzymes result most probably from the loss of interactions from helix α1 in the Δ108ST6Gal-I variant, which plays a role in acceptor substrate binding. The Km for N-acetyl-d-lactosamine was 10-fold increased for Δ108ST6Gal-I (84 mM) as compared to Δ89ST6Gal-I (8.3 mM). The two enzyme variants constitute a suitable tool box for the terminal modification of N-glycans. While the enzyme Δ89ST6Gal-I exhibited both ST (di-sialylation) and sialidase activity on a monoclonal antibody, the enzyme Δ108ST6Gal-I showed only ST activity with specificity for mono-sialylation. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|