Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Analysis of the glycosylation patterns of the extracellular domain of the epidermal growth factor receptor expressed in Chinese hamster ovary fibroblasts. 896 17

Glycosylation in cancer is a highly dynamic process that has a significant impact on tumor biology. Further, the attachment of aberrant glycan forms is already considered a hallmark of the disease state. Mass spectrometry has become a prominent approach to analyzing glycoconjugates. Specifically, matrix-assisted laser desorption/ionisation -mass spectrometric imaging (MALDI-MSI) is a powerful technique that combines mass spectrometry with histology and enables the spatially resolved and label-free detection of glycans. The most common approach to the analysis of glycans is the use of mass spectrometry adjunct to PNGase F digestion and other chemical reactions. In the current study, we perform the analysis of formalin-fixed, paraffin-embedded (FFPE) tissues for natively occurring bioactive glycan fragments without prior digestion or chemical reactions using MALDI-FT-ICR-MSI. We examined 106 primary resected gastric cancer patient tissues in a tissue microarray and correlated native-occurring fragments with clinical endpoints, therapeutic targets such as epidermal growth factor receptor (EGFR) and HER2/neu expressions and the proliferation marker MIB1. The detection of a glycosaminoglycan fragment in tumor stroma regions was determined to be an independent prognostic factor for gastric cancer patients. Native glycan fragments were significantly linked to the expression of EGFR, HER2/neu and MIB1. In conclusion, we are the first to report the in situ detection of native-occurring bioactive glycan fragments in FFPE tissues that influence patient outcomes. These findings highlight the significance of glycan fragments in gastric cancer tumor biology and patient outcome.
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PMID:Native glycan fragments detected by MALDI-FT-ICR mass spectrometry imaging impact gastric cancer biology and patient outcome. 2897 92