N-glycoproteomics and SESTAR++ analysis based on SeMOE

The isotopic envelope pattern of selenium is guaranteed by its six stable isotopes with distinctive distribution (74Se, 0.89%; 76Se, 9.37%; 77Se, 7.63%; 78Se, 23.77%; 80Se, 49.61%; 82Se, 8.73%). We postulated that the effective incorporation of selenosugar in glycoproteins would achieve direct isotopic pattern prediction for glycopeptides, without the need for secondary tagging procedures. Consequently, we performed comparative studies using a previously reported computational algorithm, the updated version of selenium-encoded isotopic signature targeted profiling (SESTAR++)31, 32, and a glycan-first glycopeptide search engine, pGlyco3 to comprehensively analyze the intact N-glycopeptides in cells treated with SeMOE probes.