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Simultaneous Affinity Enrichment of Two Post-Translational Modifications for Quantification and Site Localization
Published on: February 27, 2020
POSTMan (POST-translational modification analysis), a software application for PTM discovery
Magnus Ø Arntzen1, Christoffer Leif Osland, Christopher Rasch-Olsen Raa
1PROBE Proteomic Platform, Department of Biomedicine, University of Bergen, Bergen, Norway.
Proteomics
|March 3, 2009
Summary
POSTMan software targets low-concentration, post-translationally modified peptides for fragmentation. This method enables sequencing of previously unidentifiable modified peptides, aiding in protein analysis.
Area of Science:
- Proteomics
- Biochemistry
- Computational Biology
Background:
- Low-abundance post-translationally modified peptides are challenging to detect in mass spectrometry.
- Collision-Induced Dissociation (CID) often fails to select these low-concentration peptides, limiting sequence information.
- Accurate identification of post-translational modifications is crucial for understanding protein function and cellular processes.
Purpose of the Study:
- To develop a novel software tool, POSTMan, for targeted isolation and fragmentation of post-translationally modified peptides.
- To improve the identification of low-concentration modified peptides in complex biological samples.
- To enable comprehensive analysis of protein modifications, including phosphorylation and acetylation.
Main Methods:
- Development of POSTMan software for aligning LC-MS runs using MS(1) data.
- Utilizing user-defined mass differences to identify potential post-translationally modified peptide pairs.
- Targeting identified peptide pairs for fragmentation to obtain sequence information.
- Validation of the method using acetylated peptides and assessment of phenylalanine hydroxylase (PHA) phosphorylation.
Main Results:
- POSTMan successfully targets post-translationally modified peptides for fragmentation.
- The software enables the acquisition of sequence information for peptides previously undetectable by standard methods.
- The method demonstrated efficacy in identifying basal protein phosphorylation of PHA in intact cells.
- Validation confirmed the software's capability for analyzing acetylated peptides.
Conclusions:
- POSTMan software significantly enhances the ability to identify and analyze post-translationally modified peptides.
- This tool overcomes limitations of traditional CID-based approaches for low-abundance modified peptides.
- The method provides a valuable approach for studying protein modifications in various biological contexts.
