Photodissociation of protonated leucine-enkephalin in the VUV range of 8-40 eV.
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.
KVI Atomic and Molecular Physics, University of Groningen, Zernikelaan 25, 9747AA Groningen, The Netherlands. sadia.bari11@gmail.com
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S
Bari
O
O
Gonzalez-Magaña
G
G
Reitsma
J
J
Werner
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S
Schippers
R
R
Hoekstra
T
T
Schlathölter
D004745:Enkephalins / Q000737:chemistry*; D007930:Leucine / Q000737:chemistry*; D055668:Photochemical Processes; D011522:Protons; D011789:Quantum Theory; D014466:Ultraviolet Rays
D004745:Enkephalins; D011522:Protons; D007930:Leucine