title: Activated Ion Electron Transfer Dissociation for Improved Fragmentation of Intact Proteins.
abstract: Here we report the first implementation of activated ion electron transfer dissociation (AI-ETD) for top down protein characterization, showing that AI-ETD definitively extends the m/z range over which ETD can be effective for fragmentation of intact proteins. AI-ETD, which leverages infrared photon bombardment concurrent to the ETD reaction to mitigate nondissociative electron transfer, was performed using a novel multipurpose dissociation cell that can perform both beam-type collisional dissociation and ion-ion reactions on an ion trap-Orbitrap hybrid mass spectrometer. AI-ETD increased the number of c- and z-type product ions for all charge states over ETD alone, boosting product ion yield by nearly 4-fold for low charge density precursors. AI-ETD also outperformed HCD, generating more matching fragments for all proteins at all charge states investigated. In addition to generating more unique fragment ions, AI-ETD provided greater protein sequence coverage compared to both HCD and ETD. In all, the effectiveness of AI-ETD across the entirety of the m/z spectrum demonstrates its efficacy for robust fragmentation of intact proteins.
authors.affiliation: †Department of Chemistry, §Department of Biomolecular Chemistry, and ‡Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706, United States.
authors.forename: Nicholas M
authors.initials: NM
authors.lastname: Riley
authors.affiliation: †Department of Chemistry, §Department of Biomolecular Chemistry, and ‡Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706, United States.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Westphall
authors.affiliation: †Department of Chemistry, §Department of Biomolecular Chemistry, and ‡Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706, United States.
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Coon
mesh_terms: D000595:Amino Acid Sequence; D004579:Electron Transport; D004583:Electrons; D007477:Ions / Q000737:chemistry; D010455:Peptides / Q000032:analysis* / Q000737:chemistry; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D007477:Ions; D010455:Peptides; D011506:Proteins