Comprehensive Mapping of Protein N‑Glycosylation in Human Liver by Combining Hydrophilic Interaction Chromatography and Hydrazide Chemistry

Although
glycoproteomics is greatly developed in recent years,
our knowledge about N-glycoproteome of human tissues is still very
limited. In this study, we comprehensively mapped the N-glycosylation
sites of human liver by combining click maltose–hydrophilic
interaction chromatography (HILIC) and the improved hydrazide chemistry.
The specificity could be as high as 90% for hydrazide chemistry and
80% for HILIC. Altogether, we identified 14 480 N-glycopeptides
matched with N-!P-[S|T|C] sequence motif from human liver, corresponding
to 2210 N-glycoproteins and 4783 N-glycosylation sites. These N-glycoproteins
are widely involved into different types of biological processes,
such as hepatic stellate cell activation and acute phase response
of human liver, which all highly associate with the progression of
liver diseases. Moreover, the exact N-glycosylation sites of some
key-regulating proteins within different human liver physiological
processes were also obtained, such as E-cadherin, transforming growth
factor beta receptor and 29 members of G protein coupled receptors
family.