A facile method for cellular N-glycomic profiling by matrix-assisted laser desorption/ionization mass spectrometry

Abstract

Conventional protocols for cellular N-glycan profiling often need several time-consuming and labor-intensive steps, and a large amount of material (5–20 × 10⁶ cells) is required. In this study, an optimized co-derivatization method was applied for convenient, rapid and highly-sensitive analysis of cellular N-glycan. Taking human cervical carcinoma cells (HeLa) as a model, the required amount for comprehensive cellular N-glycans analysis was reduced down to an original cell number of 10⁵ and the total analysis time was decreased from several days to several hours. Good reproducibility of the method was also obtained with the CV averaging to less than 13.1%. In addition, compared to permethylation derivatization, more than 5-fold sensitivity improvement was achieved and more concise and clear mass spectra were obtained with the new developed method. As a preliminary study, this method was also successfully applied to reveal the difference in cellular N-glycan profiling of two heterogeneous live cell lines, human normal liver cells (L-02) and human hepatocyte carcinoma cells (HepG2), showing great potential for high-throughput analysis of N-glycans from limited cell samples, such as primary cell lines, cells obtained from cell sorting and small size cancer specimens.