Assignment of coronavirus spike protein site-specific glycosylation using GlycReSoft

Widely-available LC-MS instruments and methods allow users to acquire glycoproteomics data. Complex glycans, however, add a dimension of complexity to the data analysis workflow. In a sense, complex glycans are post-translationally modified post-translational modifications, reflecting a series of biosynthetic reactions in the secretory pathway that are spatially and temporally regulated. One problem is that complex glycan is micro-heterogeneous, multiplying the complexity of the proteome. Another is that glycopeptide glycans undergo dissociation during tandem MS that must be considered for tandem MS interpretation algorithms and quantitative tools. Fortunately, there are a number of algorithmic tools available for analysis of glycoproteomics LC-MS data. We summarize the principles for glycopeptide data analysis and show use of our GlycReSoft tool to analyze SARS-CoV-2 spike protein site-specific glycosylation.