| Autor: |
Marchal, Ingrid, Mir, Anne‐Marie, Kmiécik, Daniel, Verbert, André, Cacan, René |
| Zdroj: |
Glycobiology; Jul1999, Vol. 9 Issue 7, p645-654, 10p |
| Abstrakt: |
The most frequent type of N‐glycan synthesized by lepidopteran Sf9 cells appears to be fucosylated Man3GlcNAc2,and this has been a limitation for a large scale production and utilization of therapeutic glycoproteins in cultured insect cells. The current knowledge of the protein glycosylation pathway derived from structural studies on recombinant glyco‐proteins expressed by using baculovirus vectors. In this work we provide more direct evidence for the sequential events occurring in the processing of endogenous N‐glycoproteins of noninfected Sf9 cells. By metabolic labeling with radioactive mannose, we characterized the glycan structures which accumulated in the presence of processing inhibitors (castanospermine and swainsonine) and in the presence of an intracellular trafficking inhibitor (monensin). We thus demonstrated that from the glycan precursor Glc3Man9GlcNAc2to GlcNAcMan5(Fuc)GlcNAc2 intermediate, the processing pathwayin Sf9 cells paralleled the one demonstrated in mammalian cells. By using monensin, we demonstrated the formationof Man3(Fuc)GlcNAc2from GlcNAcMan3(Fuc)GlcNAc2, a reaction which has not been described in mammalian cells. Our results support the idea that the hexosaminidase activity is of physiological relevance to the glycosylation pathway and is Golgi located. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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