Permethylated N-glycan analysis with mass spectrometry.

Protein glycosylation plays an important role in multiple cell functions, and aberrations of protein glycosylation are associated with various malignancies including cancer. In this chapter, we provide a detailed protocol for MALDI MS analysis of permethylated N-glycans extracted from human serum proteins. The protocol includes procedures for N-glycan purification and in-solution permethylation, structural elucidation of permethylated N-glycans by MALDI-QIT-TOF MS, and construction of indices to quantify levels of certain types of glycosylation, such as fucosylation, which may serve as a potential disease biomarker.