Activated Ion-Electron Transfer Dissociation Enables Comprehensive Top-Down Protein Fragmentation

Area of Science:

• Mass spectrometry
• Proteomics
• Analytical chemistry

Background:

• Protein identification and characterization are crucial in biological research.
• Existing mass spectrometry methods like HCD, ETD, and EThcD have limitations in achieving comprehensive sequence coverage.
• Charge-state dependence can hinder the effectiveness of traditional protein sequencing techniques.

Purpose of the Study:

• To introduce and demonstrate activated ion-electron transfer dissociation (AI-ETD) for protein sequencing.
• To evaluate the performance of AI-ETD in achieving near-complete protein sequence coverage.
• To compare AI-ETD with existing methods (HCD, ETD, EThcD) for protein analysis.

Main Methods:

• Utilizing activated ion-electron transfer dissociation (AI-ETD) with concurrent infrared photoactivation.
• Employing AI-ETD to induce electron-driven dissociation of intact proteins.
• Analyzing product ions, primarily c/z-type, generated by AI-ETD.

Main Results:

• AI-ETD achieved 77-97% protein sequence coverage, demonstrating near-complete coverage.
• AI-ETD significantly outperformed HCD, ETD, and EThcD across all investigated proteins.
• The method maintained high performance irrespective of precursor ion charge states, overcoming a key limitation.

Conclusions:

• AI-ETD represents a significant advancement in protein sequencing technology.
• This method offers superior and more reliable protein sequence coverage compared to current standards.
• AI-ETD has the potential to enhance proteomic analyses by providing more comprehensive protein characterization.