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Modification and Functionalization of the Guanidine Group by Tailor-made Precursors
Published on: April 27, 2017
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Tailored photocleavable peptides: fragmentation and neutralization pathways in high vacuum
M Debiossac1, J Schätti, M Kriegleder
1Faculty of Physics, University of Vienna, VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria. markus.arndt@univie.ac.at.
Physical Chemistry Chemical Physics : PCCP
|April 13, 2018
Summary
This study demonstrates site-specific photocleavage of functionalized oligopeptides using UV light in a vacuum. The research reveals competing photodissociation pathways and their dependence on molecular structure.
Area of Science:
- Chemical Biology
- Mass Spectrometry
- Photochemistry
Background:
- Photocleavable tags (PCTs) offer precise control over molecular subunit release.
- Gas-phase chemistry of functionalized peptides is crucial for understanding complex molecular interactions.
Purpose of the Study:
- To investigate the site-specific photo-activated cleavage of ortho-nitroarylether functionalized oligopeptides in high vacuum.
- To elucidate the mechanism and influencing factors of UV photodissociation (UVPD) in gas-phase peptides.
Main Methods:
- Electrospray ionization of functionalized oligopeptides.
- UV photodissociation (UVPD) at 266 nm.
- Comparison with collision-induced dissociation (CID).
- Analysis of temperature dependence and varying molecular structures.
Main Results:
- Site-specific cleavage of peptides was achieved using UV irradiation in high vacuum.
- The cleavage mechanism was identified as thermal, supported by temperature-dependent studies.
- Two competing photodissociation pathways were observed: phenolate anion/neutral zwitterion and neutral phenol/charged peptide.
- Peptide length, phenolic group, and nitro-group position influenced cleavage outcomes.
- Gas-phase cleavage differed significantly from solution-phase behavior.
Conclusions:
- UV photodissociation provides a method for controlled peptide fragmentation in the gas phase.
- Understanding competing pathways is key to designing effective PCTs for complex molecules.
- Gas-phase photochemical studies offer unique insights distinct from solution-phase chemistry.
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