Glycosylation patterns of proteins can be highly sensitive to the local biological environment and often become aberrant in response to diseases, e.g., cancer. Consequently, accurate comparison of glycan profiles from healthy individuals with glycan profiles from patients with varying stages of cancer may provide much needed information to detect disease onset and to track disease progression. Several groups have used capillary or microchip electrophoresis to quantify differences in serum N-glycan profiles among control individuals and patients suffering from various cancers, e.g., esophageal adenocarcinoma, ovarian, and liver cancers. These differences in the glycan profiles are primarily due to up or down regulation of individual N-glycans. The next step is to identify these structures. One approach is to use an oligoglucose sizing ladder to bracket peaks of interest and calculate a glucose unit (GU) value based on the relative position of the peak of interest and the closest oligoglucose structures. Serum N-glycans and N-glycans from common glycoproteins (e.g., immunoglobulin G, fetuin, ribonuclease B, and transferrin) are enzymatically cleaved from their protein backbones and labeled with 8-aminopyrene-1,3,6-trisulfonic acid. These samples are analyzed individually and in combination with the oligoglucose internal standard by microchip electrophoresis on a 22-cm long separation channel with fluorescence detection. Glucose units for peaks in serum and from common glycoproteins are compared for direct structure identification.

Internal standards for identification of serum N-glycans by microchip electrophoresis

246th National Meeting (2013)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.