@article{7273,
  author = {U. H. Verkerk and C. K. Siu and J. D. Steill and El Aribi and J. F. Zhao and C. F. Rodriquez and J. Oomens and A. C. Hopkinson and K. W. M. Siu},
  title = {a(2) Ion Derived from Triglycine: An N-1-Protonated 4-Imidazolidinone},
  abstract = {Fragmentation of protonated peptides in the gas phase constitutes the basis for gas-phase sequencing of peptides using tandem mass spectrometry. Several mechanistic studies have indicated possible loss of b(n) ion sequence information as a consequence of macrocycle formation from internal nucleophilic attacks. Here, we show by infrared multiple-photon dissociation spectroscopy and density functional theory that the prototypical a(2) ion generated from protonated triglycine is predominantly a cyclic N-1-protonated 4-imidazolidinone. Cyclization resulting from internal nucleophilic attacks therefore may be a more general phenomenon than anticipated.},
  year = {2010},
  journal = {Journal of Physical Chemistry Letters},
  volume = {1},
  number = {5},
  pages = {868-872},
  month = {Mar},
  isbn = {1948-7185},
  url = {<Go to ISI>://000277041000013 },
  note = {ISI Document Delivery No.: 588BLTimes Cited: 0Cited Reference Count: 41},
  language = {English},
}