Loading...
SIALYLTRANSFERASES; THEIR SPECIFICITY AND THEIR USE IN CARBOHYDRATE REMODELLING.
Eijnden, Dirk H. van den Nemansky, Martin Schiphorst, Wietske E. C. M. Dedem, Gijs W. K. van Mannaerts, Bernadette M. J. L.
Eijnden, Dirk H. van den
Nemansky, Martin
Schiphorst, Wietske E. C. M.
Dedem, Gijs W. K. van
Mannaerts, Bernadette M. J. L.
Citations
Altmetric:
Advisors
Editors
Other Contributors
Issue Date
1991
Submitted date
2024-02-28
Files
Loading...
PDF
Adobe PDF, 4.89 MB
Other Titles
Abstract
In order to apply sialyltransferases in the remodelling of the carbohydrate chains on biologically active glycoproteins, it is a prerequisite to know the fine specificity of these enzymes. In this report the specificity of several sialyltransferses involved in the sialylation of O- and N-linked oligosaccharide chains is reviewed. Also novel results on the branch specificity of a3- and a6-sialyltransferase are reported. The potential application of these enzymes in carbohydrate remodelling was studied using human chorionic gonadotropin (hCG) as a model glycoprotein. Differently sialylated preparations of this hormone were obtained and tested for their stimulatory effect on steroidogenesis in Leydig cells in vitro. Asialo-hCcG appeared to be only 45% as effective as native hCG. a3-Resialylation of the O-linked chains on the ß-subunit of this hormone did not restore the biological activity to a higher level. By contrast, 55% a6- resialylation of the N-linked chains yielded a preparation which was almost as active as native hCG. Interestingly, further sialylation by the a6-sialyltransferase resulted in a decrease of the bio-activity to levels lower than obtained with asialo-hcG. It is concluded that the lectin-carbohydrate binding, which is part of the process that triggers the biological respons of the target cell can be mimicked by N-linked chains carrying a6-linked sialic acid. However, too high a density of such residues interferes with this interaction.
Citation
Protein glycosylation, 195 - 205
DOI
PubMed ID
PubMed Central ID
Additional Links
Embedded video
Type
Book chapter
conference paper
conference paper
Language
en
Description
Series/Report no.
GBF monographs ; Volume 15
ISSN
0930-4320
EISSN
ISBN
1560811846
3527283676
3527283676
ISMN
Gov't Doc #
Sponsors
License
Attribution-NonCommercial-ShareAlike 4.0 International