Lectin affinity chromatography of glycopeptides and oligosaccharides from normal and lectin-resistant Chinese-hamster ovary cells.

The [3H]mannose-labelled glycopeptides from two lectin-resistant lines of Chinese-hamster ovary cells were fractionated by chromatography on lentil lectin-Sepharose and concanavalin A-agarose columns and subsequently analysed by gel filtration in comparison with the glycopeptides of the parental cell line. Essentially all of the [3H]mannose-labelled asparaginyl-oligosaccharides from the 'single-mutant' cells selected for resistance to phytohaemagglutinin and the 'double-mutant' cells selected for additional resistance to concanavalin A were not bound to lentil lectin, whereas approximately one-sixth of the parental-cell glycopeptides were bound and specifically eluted with alpha-methyl mannoside. These bound and eluted glycopeptides represented a specific subset of the complex acidic-type asparaginyl-oligosaccharides. The percentage of radiolabelled glycopeptides and oligosaccharides from each cell line that were specifically bound to concanavalin A was consistent with the relative sensitivities of the three cell lines to this lectin. The major radiolabelled species in the endoglycosidase digest of the 'double-mutant'-cell glycopeptides (Man4GlcNAc1-size neutral oligosaccharides) were not bound to concanavalin A, whereas essentially all of the other neutral-type oligosaccharides were bound. In addition, the larger neutral-type oligosaccharides (Man8--9GlcNAc1) were more strongly bound to concanavalin A than were either the smaller neutral-type or the di-antennary acidic-type structures.