Pathways of peptide ion fragmentation induced by vacuum ultraviolet light.
One Hundred Fifty-Seven nm photodissociation of singly protonated peptides generates unusual distributions of fragment ions. When the charge is localized at the C-terminus of the peptide, spectra are dominated by x-, v-, and w-type fragments. When it is sequestered at the N-terminus, a- and d-type ions are overwhelmingly abundant. Evidence is presented suggesting that the fragmentation occurs via photolytic radical cleavage of the peptide backbone at the bond between the alpha- and carbonyl-carbons followed by radical elimination to form the observed daughter ions.
Cui
Weidong
W
Department of Chemistry, Indiana University, Bloomington, Indiana 47505-4001, USA.
Thompson
Matthew S
MS
Reilly
James P
JP
D001120:Arginine / Q000737:chemistry; D008239:Lysine / Q000737:chemistry; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D040901:Proteomics / Q000295:instrumentation / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000295:instrumentation / Q000379:methods*; D014466:Ultraviolet Rays; D014618:Vacuum
D010455:Peptides; D001120:Arginine; D008239:Lysine