Urea Artifacts Interfere with Immuno-Purification of Lysine Acetylation

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• 作者：Ana Martinez-Val ; Fernando Garcia ; Pilar Ximénez-Embún ; Ailyn Martínez Teresa-Calleja ; Nuria Ibarz ; Isabel Ruppen ; Javier Munoz
• 刊名：Journal of Proteome Research
• 出版年：2017
• 出版时间：February 3, 2017
• 年：2017
• 卷：16
• 期：2
• 页码：1061-1068
• 全文大小：493K
• ISSN：1535-3907

文摘

Comprehensive analysis of post-translational modifications (PTMs) often depends on the purification of modified peptides prior to LC–MS/MS. The implementation of these enrichment methods requires thorough knowledge of the experimental conditions to achieve optimal selectivity and sensitivity. In this regard, large-scale analysis of lysine acetylation, a key PTM for multiple cellular processes, makes use of monoclonal pan-antibodies designed against this moiety. We report that the immuno-purification of lysine-acetylated peptides is hampered by the copurification of lysine carbamylated peptides, a frequent urea artifact. This specific interaction can be explained by the similar chemical structures of lysine acetylation and lysine carbamylation. As an alternative, we propose a sample preparation protocol based on sodium deoxycholate that eliminates these artifacts and dramatically improves the selectivity and sensitivity of this immuno-purification assay.