College of Chemistry, Jilin University, Qianjin Street 2699#, Changchun, PR China.
Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Qianjin Street 2699#, Changchun, PR China.
Anal Chim Acta. 2020 Feb 22;1099:103-110. doi: 10.1016/j.aca.2019.11.058. Epub 2019 Nov 27.
Protein phosphorylation plays vital roles in the regulation of various biological processes involving in protein folding, molecular recognition, cell growth, and metabolism. It is prerequisite to develop effective enrichment methods of trace phosphopeptides before mass spectrometry (MS) analysis. In this study, we proposed a facile strategy to synthesize magnetic ionic covalent organic frameworks (FeO@iCOFs) for the capture of phosphopeptides with guanidyl as the ionic ligand instead of the post-synthetic functionalization strategy. The developed FeO@iCOFs contain a large amount of amino groups, positive charge, as well as owned superparamagnetism. The enrichment of phosphopeptides is based on the electrostatic interaction and hydrogen bonds formed between phosphate groups and guanidyl groups. By combing with MS determinations, high sensitivity of phosphopeptides (the lowest detection amount being 0.4 fmol) was achieved. The obtained material provided selective enrichment capacity of phosphopeptides from non-fat milk digest and HeLa cells, showing great potential in the detection of low-abundance phosphopeptides in complex real samples.
蛋白质磷酸化在涉及蛋白质折叠、分子识别、细胞生长和代谢等各种生物过程的调节中起着至关重要的作用。在质谱（MS）分析之前，开发有效的痕量磷酸肽富集方法是必要的。在本研究中，我们提出了一种简便的策略，即合成磁性离子共价有机框架（FeO@iCOFs），用于捕获带有胍基作为离子配体的磷酸肽，而不是采用后合成的功能化策略。所开发的 FeO@iCOFs 含有大量的氨基、正电荷，并且具有超顺磁性。磷酸肽的富集基于磷酸基团和胍基之间形成的静电相互作用和氢键。通过与 MS 测定相结合，实现了对磷酸肽的高灵敏度检测（最低检测量为 0.4 fmol）。所得材料提供了从脱脂奶消化物和 HeLa 细胞中选择性富集磷酸肽的能力，在检测复杂实际样品中的低丰度磷酸肽方面具有很大的潜力。
