Supramolecular Affinity Chromatography for Methylation-Targeted Proteomics

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• 作者：Graham A.E. Garnett ; Melissa J. Starke ; Alok Shaurya ; Janessa Li ; Fraser Hof
• 刊名：Analytical Chemistry
• 出版年：2016
• 出版时间：April 5, 2016
• 年：2016
• 卷：88
• 期：7
• 页码：3697-3703
• 全文大小：435K
• ISSN：1520-6882

文摘

Proteome-wide studies of post-translationally methylated species using mass spectrometry are complicated by high sample diversity, competition for ionization among peptides, and mass redundancies. Antibody-based enrichment has powered methylation proteomics until now, but the reliability, pan-specificity, polyclonal nature, and stability of the available pan-specific antibodies are problematic and do not provide a standard, reliable platform for investigators. We have invented an anionic supramolecular host that can form host–guest complexes selectively with methyllysine-containing peptides and used it to create a methylysine-affinity column. The column resolves peptides on the basis of methylation—a feat impossible with a comparable commercial cation-exchange column. A proteolyzed nuclear extract was separated on the methyl-affinity column prior to standard proteomics analysis. This experiment demonstrates that such chemical methyl-affinity columns are capable of enriching and improving the analysis of methyllysine residues from complex protein mixtures. We discuss the importance of this advance in the context of biomolecule-driven enrichment methods.