Two-dimensional MOF Nanosheets And MAX Materials Are Used For The Separation And Enrichment Of Glycosylated Peptides/phosphorylated Peptides

Post-translational modifications(PTMs)in proteomics is an important mechanism for eukaryotic cells to make the proteins functional diversification and to dynamically regulate the signal transduction networks.Protein glycosylation is one of the most important PTMs which plays an essential role in gene expression,cell signal transduction and immune system response.At present,the analysis of glycopeptides was mainly based on the glycoprotein tryptic digest and then mass spectrometer was used to detect glycopeptides.However,it was a great challenge to directly analyze glycopeptides with mass spectrometer due to the extremely low concentration of glycopeptides and the interference of salts.On the other hand,protein phosphorylation is another important type of PTMs in proteomics.Phosphopeptides also plays a vital character in cell signal transmission,regulation of transcription and translation,and cell apoptosis.Up to date,mass spectrometer had been widely used in the detection of phosphopeptides.However,due to the low ionization of phosphopeptides and the interference from large numbers of nonphosphopeptides,it was difficult to directly analyze phosphopeptides with mass spectrometer.Therefore,developing a nanomaterial which is simple to prepare,low in cost and highly efficient enrichment of glycopeptides/phosphopeptides has attracted more and more attention.In the dissertation,we mainly focused on the nanomaterials which were simple synthesis,low cost,strong hydrophilicity and large surface area.Thereafter,we used the new nanomaterials in the enrichment of glycopeptides/phosphopeptides and developed an efficient and rapid enrichment method,and we also evaluated the nanomaterials' enrichment efficiency in the real complex biosamples.The mainly research content and experimental results were summarized as follows:(1)Top-Down Synthesized Hydrophilic Ti-MOF Nanosheets for Highly Selective Enrichment of Glycopeptides and Human Serum ProfilingIn this chapter,we introduced a top-down synthesized hydrophilic Ti-MOF nanosheets to selective enrichment of glycopeptides.The 2D Ti-MOF nanosheets have unique properties,such as more active sites,abundant surface hydroxyl groups and strong hydrophilicity.Thereafter,we optimized the enrichment solution,time and the amount of materials and we also investigated the enrichment detection limit,selectivity and material repeatability.Finally,Ti-MOF nanosheets were applied in the serum glycoproteinomics.(2)Enrichment of Glycopeptides with Bottom-Up Synthesized Highly Hydrophilic Hf-MOF Nanosheets for Human Serum Profiling and Glycoproteomics AnalysisAs to the low exfoliation yield and poor enrichment efficiency in the last chapter,we introduced a bottom-up directly synthesized Hf-MOF nanosheets for the specific enrichment of glycopeptides in this chapter.The 2D Hf-MOF nanosheets have a simple synthesis method,high yield,abundant surface hydroxyl groups and excellent hydrophilicity.Thereafter,we optimized the enrichment solution,elute solution and the amount of materials.We also evaluated the enrichment detection limit,recovery and material repeatability.Finally,Hf-MOF nanosheets were applied in the serum glycoproteinomics.(3)MAX Nanomaterials for Dual Enrichment of Phosphopeptides/Glycopeptides and Biosamples ProfilingIn this chapter,we introduced a MAX nanomaterials for dual enrichment of phosphopeptides/glycopeptides.Both phosphorylation/glycosylation are two types of post-translational modifications which play a vital role in proteomics.However,there were few literatures that had been reported for simultaneously enriching phosphopeptides/glycopeptides.Thereafter,the standard phosphoprotein/glycoprotein tryptic digest and complex samples including mouse brain and human serum were selected to evaluate the enrichment efficiency of MAX nanomaterials.By optimizing the enrichment conditions,it showed a good phosphopeptides/glycopeptides enrichment results.Finally,we expounded the potential application prospects of MAX nanomaterials in phosphorylated/glycosylated proteomics in the future.In summary,the dissertation mainly focused on the bad selectivity and low detection limit in the enrichment of glycopeptides/phosphopeptides in proteomics.Then we have developed 2D MOF nanosheets and MAX nanomaterials to achieve efficiently enrich glycopeptides and phosphopeptides which could provide new strategies for highly efficient enrichment in the future.