Hydrophilic probe in mesoporous pore for selective enrichment of endogenous glycopeptides in biological samples.

As one of the most important post-translational modifications (PTMs) of peptidome, glycopeptidome is closely related to serious disease, especially to cancer. In order to specifically discover and analyze glycopeptidome biomarkers for clinical diagnosis of cancer on early-stage, it is crucial to develop efficient technique to analyze low-abundance of endogenous glycopeptides in biological samples. In this report, a hydrophilic probe in mesoporous pore (denoted as FeO@mSiO@G6P) was designed and prepared. By taking advantage of the excellent hydrophilicity and size-exclusion ability, we applied FeO@mSiO@G6P to capture glycopeptides from both horseradish peroxidase (HRP) and immunoglobulin (IgG) digests successfully. Moreover, a total of 39 and 25 endogenous glycopeptides were identified from healthy saliva and gastric saliva, respectively, indicating the great potential of this probe for the exploration of glycopeptidome biomarkers.