Enrichment Workflow for Pyrophosphoproteome Analysis

Area of Science:

• Biochemistry
• Proteomics
• Analytical Chemistry

Background:

• Detecting diverse posttranslational modifications (PTMs) across the proteome remains an analytical challenge.
• Protein pyrophosphorylation is a recently identified PTM that requires specialized detection methods.
• Characterizing substoichiometric modifications like pyrophosphorylation in complex biological samples is difficult.

Purpose of the Study:

• To describe a bottom-up pyrophosphoproteomics workflow for identifying protein pyrophosphorylation sites.
• To detail an enrichment strategy crucial for detecting this modification.
• To present mass spectrometry (MS) based analysis for endogenous pyrophosphorylation.

Main Methods:

• Implementation of a specific enrichment workflow for pyrophosphorylated peptides.
• Utilizing data-dependent neutral-loss triggered electron transfer/higher-energy collision dissociation (DDNL EThcD) MS.
• Bottom-up proteomics analysis of enriched complex cell lysate samples.

Main Results:

• Successful identification of endogenous protein pyrophosphorylation sites.
• Demonstration of an effective enrichment strategy for substoichiometric PTMs.
• Characterization of pyrophosphorylation within complex proteomic samples.

Conclusions:

• The described pyrophosphoproteomics workflow enables the detection of protein pyrophosphorylation sites.
• Enrichment strategies are critical for analyzing low-abundance PTMs.
• MS-based approaches, particularly DDNL EThcD, are powerful tools for pyrophosphorylation discovery.