Spectroscopic evidence for mobilization of amide position protons during CID of model peptide ions.
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.
Molesworth
Samuel
S
Department of Chemistry, Wichita State University, Wichita, Kansas 67260-0051, USA.
Leavitt
Christopher M
CM
Groenewold
Gary S
GS
Oomens
Jos
J
Steill
Jeffrey D
JD
van Stipdonk
Michael
M
D000577:Amides / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D008958:Models, Molecular; D009525:Niacin / Q000737:chemistry; D010455:Peptides / Q000737:chemistry*; D011522:Protons; D013055:Spectrophotometry, Infrared / Q000379:methods*
D000577:Amides; D010455:Peptides; D011522:Protons; D009525:Niacin; D005998:Glycine