Sun, S. et al. Nat. Biotechnol. doi:10.1038/nbt.3403 (16 November 2015).

Protein glycosylation is a functionally important but very complex type of post-translational modification. It has thus remained an experimental challenge to comprehensively characterize glycan structures as well as their site-specific locations on proteins on a proteomic scale. Sun et al. have reported an approach that enables researchers to thoroughly characterize N-linked glycoproteins. Their method involves conjugation of digested peptides to a solid support; chemical modification of both peptide and glycan to facilitate mass spectrometry analysis, followed by the release of the glycans and peptides from the support; identification by mass spectrometry; and finally reconstruction of the intact N-glycopeptides from the mass spectrometry data. This approach provides information about the total N-glycan, peptide glycosite and glycoprotein content in complex samples and was used to observe the effects of an N-linked glycosylation inhibitor on ovarian cancer cells.