N-glycomics and N-glycoproteomics of human cerebrospinal fluid

International audienceProtein glycosylation is one of the most complex types of posttranslational modifications of proteins. Disorders of the central nervous system can lead to particular patterns of glycans bound to proteins from cerebrospinal fluid (CSF). In this chapter, we first provide a detailed protocol for obtaining relevant mass spectrometric profiles of CSF N-glycans after permethylation (N-glycomics). In addition, we describe how to perform enrichment of tryptic glycopeptides from CSF proteins by hydrophilic interaction in an efficient and reproducible manner. Resulting glycopeptides can be either analyzed directly by nano-liquid chromatography/tandem mass spectrometry (N-glycoproteomics) or after de-N-glycosylation. We also indicate how relevant site-specific information data can be obtained for most CSF proteins by combining the data from the analysis of N-glycans, N-glycopeptides, and deglycosylated peptides