1. Post-synthesis of a titanium-rich magnetic COF nanocomposite with flexible branched polymers for efficient enrichment of phosphopeptides from human saliva and serum.
- Author
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Meng, Luyan, Wang, Bing, Wang, Baichun, Feng, Quanshou, Zhang, Sijia, Xiong, Zi, Zhang, Shun, Cai, Ting, Ding, Chuan-Fan, and Yan, Yinghua
- Subjects
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BRANCHED polymers , *PHOSPHOPEPTIDES , *AFFINITY chromatography , *NANOCOMPOSITE materials , *ION exchange chromatography , *SALIVA , *POLYMERS , *TRANSCRANIAL magnetic stimulation - Abstract
A Ti4+-functionalized magnetic covalent organic framework material with flexible branched polymers (mCOF@ε-PL@THBA-Ti4+) built via an immobilized metal ion affinity chromatography (IMAC) enrichment strategy was proposed through post-synthesis modification. Hydrophilic ε-poly- L -lysine (ε-PL) rich in amino active groups was first introduced in the fabrication of the phosphopeptide enrichment material to increase the hydrophilicity while providing more functional modification pathways of the material. 2,3,4-Trihydroxy-benzaldehyde (THBA) provides abundant binding sites for the immobilization of numerous Ti4+, which is advantageous for the subsequent efficient phosphopeptide enrichment. The magnetic nanocomposite exhibited outstanding performance of phosphopeptide enrichment with good selectivity (1 : 5000), a low detection limit (2 fmol), and relatively high loading capacity (66.7 mg g−1). What's more, after treatment with mCOF@ε-PL@THBA-Ti4+, 16 endogenous phosphopeptides from fresh saliva of healthy people were recognized by MALDI-TOF MS, and 50 phosphopeptides belonging to 35 phosphoproteins from the serum of uremia patients were detected by nano-LC-MS/MS. Proteomics data analysis for the differential protein selection between uremia and normal controls was conducted using R software, and four down-regulated and three up-regulated proteins were obtained. The results suggested that the prepared material has potential applications in biomarker discovery. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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