ABSTRACT
Glycosylation is a posttranslational modifi cation of high relevance for proteins in biological systems,1 as is the alteration of these glycoproteins in disease and disease progression.2 The analysis of glycoproteins can be often masked by more abundant nonglycosylated proteins (e.g., albumin, IgG, and fi brinogen in human plasma). This chapter describes methods of enriching biological samples for glycoproteins prior to one-dimensional (1D) and two-dimensional polyacrylamide gel electrophoresis (2D PAGE). We fi rst describe methods using lectin and boronate affi nity chromatography to enrich for subfractions of glycoproteins.3 We then describe the separation and detection of these glycoproteins by 2D PAGE. In our laboratory we then use
these gel-separated glycoproteins for the release of N-and O-linked oligosaccharides, separation of these by graphitized carbon liquid chromatography, and analysis by electrospray mass spectrometry. The interpretation of the resulting fragmentation mass spectra is then facilitated by use of our glycoinformatic tools.
