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Electron capture dissociation of weakly bound polypeptide polycationic complexes
Kim F Haselmann1, Thomas J D Jørgensen, Bogdan A Budnik
1Department of Chemistry, University of Southern Denmark, Odense, Denmark. kfh@chem.sdu.dk
Rapid Communications in Mass Spectrometry : RCM
|December 13, 2002
Summary
Electron capture dissociation (ECD) can break strong internal bonds in molecular complexes without disrupting weaker external bonds. This study demonstrates this phenomenon in peptide and antibiotic complexes, supporting a specific cleavage mechanism.
Area of Science:
- Mass Spectrometry
- Chemical Physics
- Molecular Interactions
Background:
- Electron capture dissociation (ECD) is a method for peptide and protein analysis.
- Previous work suggested ECD can selectively cleave intramolecular bonds over intermolecular ones in supramolecular aggregates.
Purpose of the Study:
- To provide further evidence for selective intramolecular bond cleavage during ECD.
- To investigate this phenomenon in various peptide and glycopeptide antibiotic complexes.
Main Methods:
- Electron Capture Dissociation (ECD) experiments.
- Blackbody infrared dissociation (BIRD) analysis.
- Low-energy collisional excitation studies.
- Force-field simulations.
Main Results:
- Demonstrated selective rupture of strong intramolecular bonds in peptide-peptide dimers and glycopeptide-peptide complexes.
- Confirmed weak intermolecular bonding using BIRD, collisional excitation, and simulations.
- Observed ECD cleavage consistent with a non-ergodic mechanism.
Conclusions:
- ECD facilitates targeted dissociation of strong internal bonds within weakly bound molecular assemblies.
- The findings support a non-ergodic mechanism governing ECD cleavage in these systems.
- This selective cleavage has implications for studying complex molecular interactions.