Title : Analysis of the glycosylation patterns of the extracellular
domain of the
epidermal growth factor receptor expressed in Chinese hamster ovary fibroblasts
Abstract :
- The extracellular domain (621 N-terminal amino acids) of the p170 epidermal growth factor ( EGF ) receptor has eleven consensus N-linked glycosylation sites
- When expressed in Chinese hamster ovary cells this was glycosylated with a combination of high mannose and complex chains.
- The latter chains were shown by chromatographic separation and mass spectrometric analysis of tryptic digests to be clustered in the EGF-binding domain
- Treatment with the endoglycosidase , peptide-N-glycosidase F ( PNGase F), reduced the molecular weight from 110 kDa to 75 kDa
- Released oligosaccharides were characterised at high sensitivity by high pH anion exchange chromatography with pulsed amperometric detection and gas-liquid chromatography/mass spectrometry
- The data were consistent with the complex chains being trisialylated tetra-antennary oligosaccharides fucosylated on the reducing terminal GlcNAc.
- The large hydrodynamic mass of these oligosaccharides could influence ligand binding, an effect which is likely to vary with the difference in consensus glycosylation sites of proteins related to p170 i .e. p185erbB2/neu, p180erbB3 and p180erbB4