Photodissociation of protonated leucine-enkephalin in the VUV range of 8-40 eV

J Chem Phys. 2011 Jan 14;134(2):024314. doi: 10.1063/1.3515301.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Enkephalins / chemistry*
  • Leucine / chemistry*
  • Photochemical Processes
  • Protons*
  • Quantum Theory
  • Ultraviolet Rays*

Substances

  • Enkephalins
  • Protons
  • Leucine