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Published on: October 23, 2018
Photodissociation of protonated leucine-enkephalin in the VUV range of 8-40 eV
S Bari1, O Gonzalez-Magaña, G Reitsma
1KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen, The Netherlands. sadia.bari11@gmail.com
Abstract:
Until now, photodissociation studies on free complex protonated peptides were limited to the UV wavelength range accessible by intense lasers. We have studied photodissociation of gas-phase protonated leucine-enkephalin cations for vacuum ultraviolet (VUV) photons energies ranging from 8 to 40 eV. We report time-of-flight mass spectra of the photofragments and various photofragment-yields as a function of photon energy. For sub-ionization energies our results are in line with existing studies on UV photodissociation of leucine-enkephalin. For photon energies exceeding 10 eV we could identify a new dissociation scheme in which photoabsorption leads to a fast loss of the tyrosine side chain. This loss process leads to the formation of a residual peptide that is remarkably cold internally.
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