Obtaining complementary polypeptide sequence information from a single precursor ion packet via sequential ion...

Area of Science:

• Proteomics
• Analytical Chemistry
• Biochemistry

Background:

• Tandem mass spectrometry (MS/MS) is crucial for protein and peptide structure determination.
• Single dissociation methods in MS/MS often yield incomplete sequence and post-translational modification data.
• Using multiple fragmentation methods improves data but reduces analytical efficiency.

Purpose of the Study:

• To present a proof-of-concept for a new MS/MS method.
• To overcome limitations of single dissociation methods in peptide and protein characterization.
• To improve the effective duty cycle in mass spectrometry analyses.

Main Methods:

• Integration of collision-induced dissociation (CID) and electron transfer dissociation (ETD) fragmentation.
• Utilizing ion mobility (IM) to temporally separate CID and ETD events on a single ion packet.
• Acquiring complementary fragmentation data from both CID and ETD.

Main Results:

• Demonstrated successful application on polypeptides (1.3–8.6 kDa).
• Achieved IM-resolved CID and ETD, yielding distinct b/y and c/z fragment ions.
• Showcased utilization of unreacted ions in ETD for CID, improving ion economy.

Conclusions:

• The combined CID and ETD method with IM enhances peptide and protein structural characterization.
• This approach increases the utilization of the precursor ion population.
• The method achieves comprehensive fragmentation data with minimal loss in duty cycle.