N-glycopedia: libraries for native N-glycan structural analysis

Measurements of glycans modifying glycoproteins are hampered by the lack of standards that reflect the wide diversity in structure typically observed. To this end we exploit a large library of N-glycan standards comprised of a unique collection of 226 N-glycans including oligomannose, hybrid, and complex-type and apply a method employing porous graphitised carbon (PGC) and liquid chromatography mass spectrometry (PGC-LC-MS) to provide a high-resolution separation and characterisation of underivatized N-glycan structures. Chromatogram libraries arising from this study include retention time data, diagnostic fragments, and validated structural assignments, providing a robust platform for both targeted and discovery-based glycomics. Here we establish this generated data as an N-glycopedia, the resource in which researchers can compare this collective data to N-glycans under study and overcome the limitations of only having compositional data and predicted structures. The technology is easily expandable to include additional N-glycans as new standards become available. Researchers created N-glycopedia, a reference library of 226 sugar molecules found on proteins, enabling a native glycomics method to precisely identify and measure these sugars, which influence immunity and disease, without chemical pre-treatment.