Spectroscopic evidence for mobilization of amide position protons during CID of model peptide ions

J Am Soc Mass Spectrom. 2009 Oct;20(10):1841-5. doi: 10.1016/j.jasms.2009.06.007. Epub 2009 Jul 1.

Abstract

Infrared multiple photon dissociation (IRMPD) spectroscopy was used to study formation of b2+ from nicotinyl-glycine-glycine-methyl ester (NicGGOMe). IRMPD shows that NicGGOMe is protonated at the pyridine ring of the nicotinyl group, and more importantly, that b2+ from NicGGOMe is not protonated at the oxazolone ring, as would be expected if the species were generated on the conventional bn+/yn+ oxazolone pathway, but at the pyridine ring instead. IRMPD data support a hypothesis that formation of b2+ from NicGGOMe involves mobilization and transfer of an amide position proton during the fragmentation reaction.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amides / chemistry
  • Glycine / chemistry
  • Mass Spectrometry / methods*
  • Models, Chemical*
  • Models, Molecular
  • Niacin / chemistry
  • Peptides / chemistry*
  • Protons
  • Spectrophotometry, Infrared / methods*

Substances

  • Amides
  • Peptides
  • Protons
  • Niacin
  • Glycine