Electron transfer dissociation of peptide anions.
Ion/ion reactions of multiply deprotonated peptide anions with xenon radical cations result in electron abstraction to generate charge-reduced peptide anions containing a free-radical site. Peptide backbone cleavage then occurs by hydrogen radical abstraction from a backbone amide N to facilitate cleavage of the adjacent C-C bond, thereby producing a- and x-type product ions. Introduction of free-radical sites to multiply charged peptides allows access to new fragmentation pathways that are otherwise too costly (e.g., lowers activation energies). Further, ion/ion chemistry, namely electron transfer reactions, presents a rapid and efficient means of generating odd-electron multiply charged peptides; these reactions can be used for studying gas-phase chemistries and for peptide sequence analysis.
Coon
Joshua J
JJ
Department of Chemistry, University of Virginia, McCormick Road, Charlottesville, VA 22908, USA. jcoon@virginia.edu
Shabanowitz
Jeffrey
J
Hunt
Donald F
DF
Syka
John E P
JE
D000595:Amino Acid Sequence; D000838:Anions / Q000737:chemistry; D004579:Electron Transport; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D055672:Static Electricity
D000838:Anions; D010455:Peptides