Immobilized metal ion affinity chromatography ZipTip pipette tip with polydopamine modification and Ti4+ immobilization for selective enrichment and isolation of phosphopeptides

• It shows good selectivity, sensitivity and stability to phosphopeptides.
• It is ease of use, small sample, solvent consumption and less carry-over.
• It leads to directly speedy and high-throughput MALDI MS analysis.

As an effective tool in protein analysis, mass spectroscopy (MS) has been widely used in identifying protein phosphorylation and phosphorylation sites. Because of the low abundance of phosphopeptides in protein digestion, isolation and enrichment of phosphopeptides prior to MS analysis is important for efficient phosphopeptides identification. In this work, we initially immobilized titanium ions on polydopamine (PDA)-modified ZipTip pipette tips (denoted as IMAC ZipTip pipette tip) for simple and quick enrichment of phosphopeptides. The preparation process of the novel ZipTip pipette tips is fast and economic since it only contains two simple steps both with mild conditions. The ability of modified ZipTip pipette tips for identifying phosphopeptides in complex biological samples was investigated. The unique ZipTip pipette tip not only exhibited superior ability in selectively capturing phosphopeptides from large amount of non-phosphopeptides, but also remarkably shortened the MS preparation and analysis time, making it an easy-to-use and efficient tool in phosphoproteome research.

In this study, we initially immobilized titanium ions on polydopamine (PDA)-modified ZipTip pipette tips (denoted as IMAC ZipTip pipette tip) for simple and quick enrichment of phosphopeptides. The unique ZipTip pipette tip not only exhibited superior ability in selectively capturing phosphopeptides from large amount of non-phosphopeptides, but also remarkably shortened the MS preparation and analysis time.Figure optionsDownload as PowerPoint slide