Faculty of Chemistry, University of Wroclaw, 50-383 Wroclaw, Poland.
Department of Molecular Microbiology, Faculty of Biotechnology, University of Wroclaw, 50-383 Wroclaw, Poland.
Molecules. 2020 Mar 18;25(6):1372. doi: 10.3390/molecules25061372.
High complexity of cell and tissue proteomes limits the investigation of proteomic biomarkers. Therefore, the methods of enrichment of some chemical groups of peptides including thiopeptides are important tools that may facilitate the proteomic analysis by reducing sample complexity and increasing proteome coverage. Here, we present a new method of cysteine-containing tryptic peptide enrichment using commercially available TentaGel R RAM resin modified by the linker containing the maleimide group, allowing thiol conjugation. The captured tryptic peptides containing lysine residue were then tagged by 2,4,6-triphenylpyrylium salt to form 2,4,6-triphenylpyridinium derivatives, which increases the ionization efficiency during mass spectrometry analysis. This makes it possible to conduct an ultrasensitive analysis of the trace amount of compounds. The proposed strategy was successfully applied in the enrichment of model tryptic podocin peptide and podocin tryptic digest.
细胞和组织蛋白质组的高度复杂性限制了对蛋白质组生物标志物的研究。因此，包括硫肽在内的某些肽类化学基团的富集方法是重要的工具，可通过降低样品复杂性和增加蛋白质组覆盖度来促进蛋白质组分析。在这里，我们提出了一种新的方法，使用商业上可获得的通过含有马来酰亚胺基团的连接子修饰的 TentaGel R RAM 树脂来富集含有半胱氨酸的胰蛋白酶肽，允许巯基结合。然后，含有赖氨酸残基的捕获的胰蛋白酶肽通过 2,4,6-三苯基吡嗪盐进行标记，形成 2,4,6-三苯基吡啶鎓衍生物，这在质谱分析期间增加了离子化效率。这使得对痕量化合物进行超灵敏分析成为可能。所提出的策略成功地应用于模型胰蛋白酶足细胞肽和足细胞胰蛋白酶消化物的富集。
