Synergistic synthesis of hydrophilic hollow zirconium organic frameworks for simultaneous recognition and capture of phosphorylated and glycosylated peptides.

Highly efficient extraction of phospho- and glycopeptides from complicated biological samples is extremely crucial for comprehensive characterization of protein phosphorylation and glycosylation based on mass spectrometry (MS). In this work, a new synergistic strategy that combined surface covalent modification and alkaline etching was developed to synthesize hydrophilic hollow zirconium-organic frameworks (HHZr-MOFs) for simultaneous recognition and capture of phospho- and N-glycopeptides. The unique properties including high specific surface area, mesoporous shell and hollow cavity endowed HHZr-MOFs with facilitated mass transport and abundant accessible active sites. Benefited from the maltose modified on the external surface and Zr-O clusters retained on the internal surface, HHZr-MOFs could act as a highly efficient bifunctional probe for simultaneous enrichment of phospho- and N-glycopeptides based on hydrophilic interaction chromatography (HILIC) and metal oxide affinity chromatography (MOAC), respectively. Finally, a total of 98 endogenous phosphopeptides and 216 endogenous N-glycopeptides were simultaneously captured by HHZr-MOFs from saliva samples of patients with oral inflammation, and several phospho- and glycoproteins related with coagulation, bacterial defense and immune response for oral inflammation were identified by Gene ontology (GO) analyses, confirming the great potential of HHZr-MOFs in rapid detection of clinical biomarkers and comprehensive profiling of phosphoproteomic and glycoproteomic for complex biological samples. This work not only provides an alternative method to precisely design and synthesize sophisticated hollow MOFs with multifunctionalities, but also offers a novel concept of multifunctional material design for bioseparation and analysis in modification-specific proteomics.