Quantitative cleavage of the N-glycosidic bond under the normal conditions of methanolysis used for the analysis of glycoprotein monosaccharides.
The most common method used for the liberation of monosaccharides from glycoprotein N-glycans involves anhydrous methanolysis because it liberates almost quantitatively monosaccharides as O-methylglycosides, which are resistant to further degradation. However, it is generally assumed that this method does not cleave quantitatively the N-glycosidic bonds. This paper demonstrates that classical methanolysis conditions quantitatively cleave the N-glycosidic bond (96%), liberating glucosamine (and not its O-methylglycosides) and other minor reaction products which were identified. Because other N-acetyl-d-glucosamine (GlcNAc) residues are quantitatively liberated as the O-methylglycosides of glucosamine, the GlcNAc residue involved in the N-glycosidic bond is separated from the others using gas chromatography of heptafluorobutyrate derivatives.
Laboratoire de Chimie Biologique, CNRS UMR 111, Villeneuve d'Ascq Cedex, 59655, France.
E
E
Maes
G
G
Strecker
P
P
Timmerman
Y
Y
Leroy
J P
JP
Zanetta
D002849:Chromatography, Gas; D008401:Gas Chromatography-Mass Spectrometry; D006023:Glycoproteins / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D009005:Monosaccharides / Q000032:analysis*; D011134:Polysaccharides / Q000032:analysis
D006023:Glycoproteins; D009005:Monosaccharides; D011134:Polysaccharides