A novel titanium dioxide-polydimethylsiloxane plate for phosphopeptide enrichment and mass spectrometry analysis

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• 作者：Chao-Jung Chen ; Chien-Chen Lai ; Mei-Chun Tseng ; Yu-Ching Liu ; Yu-Huei Liu ; Liang-Wei Chiou ; Fuu-Jen Tsai
• 关键词：Phosphopeptide ; Titanium dioxide ; Polydimethylsiloxane ; Plate ; Mass spectrometry ; Phosphoproteomics
• 刊名：Analytica Chimica Acta
• 出版年：17 February, 2014
• 年：2014
• 卷：812
• 期：Complete
• 页码：105-113
• 全文大小：1758 K

文摘

The phosphorylation of proteins is a major post-translational modification that is required for the regulation of many cellular processes and activities. Mass spectrometry signals of low-abundance phosphorylated peptides are commonly suppressed by the presence of abundant non-phosphorylated peptides. Therefore, one of the major challenges in the detection of low-abundance phosphopeptides is their enrichment from complex peptide mixtures. Titanium dioxide (TiO₂) has been proven to be a highly efficient approach for phosphopeptide enrichment and is widely applied. In this study, a novel TiO₂ plate was developed by coating TiO₂ particles onto polydimethylsiloxane (PDMS)-coated MALDI plates, glass, or plastic substrates. The TiO₂-PDMS plate (TP plate) could be used for on-target MALDI-TOF analysis, or as a purification plate on which phosphopeptides were eluted out and subjected to MALDI-TOF or nanoLC-MS/MS analysis. The detection limit of the TP plate was 鈭?0-folds lower than that of a TiO₂-packed tip approach. The capacity of the 鈭?.5 mm diameter TiO₂ spots was estimated to be 鈭?0 渭g of 尾-casein. Following TiO₂ plate enrichment of SCC4 cell lysate digests and nanoLC-MS/MS analysis, 鈭?2% of the detected proteins were phosphorylated, illustrating the sensitivity and effectiveness of the TP plate for phosphoproteomic study.