Complete glycosylation of the insulin and insulin-like growth factor I receptors is not necessary for their biosynthesis and function. Use of swainsonine as an inhibitor in IM-9 cells.

摘要: Swainsonine, an indolizidine alkaloid which is a potent inhibitor of the Golgi enzyme, mannosidase II, leads to production incompletely processed glycoproteins lacking complex type oligosaccharides. This has been used examine importance terminal sugar groups in biosynthesis and function both insulin receptor insulin-like growth factor I receptor. IM-9 cells were metabolically labeled using [35S]methionine two receptors independently immunoprecipitated specific monoclonal antibodies. The have slightly lower molecular weights contain hybrid rather than oligosaccharides as indicated by their sensitivity endoglycosidase H neuraminidase. Both made presence swainsonine are still autophosphorylated respective hormone. can be affinity at cell surface 125I-insulin disuccinimidyl suberate cross-linking; there also no significant difference its for insulin. These results suggest that synthesized, processed, normally, they do not require all sugars normally added stages glycosylation.