High-Sensitivity Glycoproteomic Analysis of Biological Samples by CZE-ESI-MS.

Capillary zone electrophoresis-tandem mass spectrometry (CZE-MS/MS) is a powerful tool for the characterization and identification of the macro- and microheterogeneity of a glycoprotein in a bottom-up approach. This chapter describes in detail the sample preparation procedures using a purified biological sample, prostate-specific antigen, as a model protein, including proteolytic digestion (trypsin). In addition, insights are provided into the strengths of using capillary electrophoresis for obtaining isomer separation of differently linked sialic acids. Lastly, approaches and potential pitfalls for the integration and quantitation of glycopeptide signals from the obtained CZE-MS data are discussed.