English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

The factors regulating modifications of terminal beta-Gal residues in lactosaminyl (Gal beta 1--&gt;4GlcNAc beta--&gt;R) units in intact glycoproteins are not well understood. To examine these factors, rat liver alpha 2,3 sialyltransferase (alpha 2,3ST) and alpha 2,6 sialyltransferase (alpha 2,6ST) and the murine alpha 1,3 galactosyltransferase (alpha 1,3GT) were incubated with a variety of well-defined desialylated glycoproteins and with glycoproteins in extracts of the Lec2 mutant CHO cells. Lec2 cells constitutively synthesize nonsialylated glycoproteins with terminal lactosaminyl sequences. The results demonstrate that each enzyme displays preferences for glycoprotein acceptors and in the types of N-glycans recognized. The alpha 2,3ST, in contrast to the alpha 2,6ST and alpha 1,3GT, prefers more branched N-glycans compared to diantennary N-glycans. However, only the alpha 1,3GT is able to efficiently modify polylactosamines (3Gal beta 1--&gt;4GlcNAc beta 1--&gt;)n in N-glycans. Glycopeptides were also prepared by proteolysis of Lec2 glycoproteins and tested as acceptors compared to intact Lec2 glycoproteins. The alpha 2,6ST and alpha 1,3GT utilized intact glycoproteins and glycopeptides with a 2-fold preference for the former over the latter. In contrast, the alpha 2,3ST showed a 20-fold preference for intact glycoproteins over glycopeptides. These results demonstrate that each of these terminal glycosyltransferases differentially recognizes glycans and glycoprotein acceptors, and that the alpha 2,3ST requires peptide features for efficient utilization of branched N-glycan acceptors.

Differential recognition of glycoprotein acceptors by terminal glycosyltransferases