Application of Ti⁴⁺ embedded functional composite materials in simultaneous enrichment of glycopeptides and...

Glycosylation and phosphorylation of proteins represent crucial forms of post-translational modifications (PTMs), playing pivotal roles in various biological processes. Research indicates a strong correlation between the development of type 2 diabetes (T2D) and abnormal protein translation in the body. Therefore, studying glycosylation and phosphorylation at the molecular level can be used for monitoring disease progression and refining research methodologies. In this study, the material is modified and functionally engineered by utilizing graphene oxide (GO) as the substrate, and incorporating titanium ions (Ti⁴⁺) into chondroitin sulfate. The composite was successfully applied to the selective enrichment of glycopeptides and phosphopeptides by utilizing the bifunctionality of hydrophilic interaction chromatography and metal ion chelation chromatography. This approach allowed for the capture of 57 glycopeptides and 2 phosphopeptides from normal human serum, and 141 glycopeptides and 10 phosphopeptides from T2D serum, respectively. This approach effectively tackles the challenges of detecting low-abundance glycopeptides and phosphopeptides in complex environments, enabling the successful capture from serum samples. The design and application of this material provide new insights into the development of PTMs and their connection to the study of T2D diabetes.