Swift Universal Glycan Acquisition (SUGA) Enables Quantitative Glycan Profiling Across Diverse Sample Types

The ability to rapidly analyze complex mixtures of glycans derived from glycoproteins is important, but the techniques are often laborious and require multiple glycan derivatization steps. Here we describe an approach termed Swift Universal Glycan Acquisition (SUGA) in which the total released, native, non-reduced N-glycan samples are analyzed following direct injection and electrospray ionization in a mass spectrometer with a rapid 3-minute run time for each sample. As electrospray ionization (ESI) can generate multiple adducts for the same glycan composition (MS1), deconvolution was performed to yield the relative intensity profile for each glycan composition detected; each annotated composition is supported by an annotated MS2 spectrum. This combination of MS1 and MS2 data enables confident glycan identification. The data obtained by SUGA were comparable to those obtained using permethylated N-glycans analyzed by matrix-assisted laser-desorption/ionization (MALDI)-MS. The SUGA approach was applied to the analyses of several purified glycoproteins and N-glycans derived from cells and compared to spectra obtained following permethylation and analysis by MALDI-MS.