N-Glycopedia: Libraries for Native N-glycan Structural Analysis

Abstract

Studies on glycans of glycoproteins are hampered by the lack of standards that reflect the wide diversity in structure typically observed. To this end we have exploited a large library of N-glycan standards comprised of a unique collection of 226 N-glycans including oligomannose, hybrid, and complex-type. We generated a method employing porous graphitized carbon (PGC) and liquid chromatography mass spectrometry (PGC-LC-MS), which can provide a high degree of resolution of underivatized N-glycan structures. Chromatogram libraries arising from these studies include retention time data, diagnostic fragments, and validated structural assignments, providing a robust platform for both targeted and discovery-based glycomics. We refer to this as an N-glycopedia, the first type of 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.