Fragmentation of oligoribonucleotides from gas-phase ion-electron reactions
- University of Michigan, Department of Chemistry (United States)
We have recently demonstrated that both electron capture dissociation (ECD) and electron detachment dissociation (EDD) can provide complementary sequence-specific cleavage of DNA compared with collision activated dissociation (CAD) and infrared multiphoton dissociation (IRMPD). However, EDD is preferred because of more extensive fragmentation at higher sensitivity (due to its negative ion mode operation). Here, we extend the radical ion chemistry of these two gas-phase ion-electron reaction techniques to the characterization of RNA. Compared with DNA, rather limited information is currently available on the gas-phase fragmentation of RNA. We found that the ECD fragmentation patterns of the oligoribonucleotides A{sub 6}, C{sub 6}, and CGGGGC are nucleobase dependent, suggesting that cleavage proceeds following electron capture at the nucleobases. Only limited backbone cleavage was observed in ECD. EDD, on the other hand, provided complete sequence coverage for the RNAs A{sub 6}, C{sub 6}, G{sub 6}, U{sub 6}, CGGGGC, and GCAUAC. The EDD fragmentation patterns were different from those observed with CAD and IRMPD in that the dominant product ions correspond to d-and w-type ions rather than c- and y-type ions. The minimum differences between oligoribonucleotides suggest that EDD proceeds following direct electron detachment from the phosphate backbone.
- OSTI ID:
- 22774085
- Journal Information:
- Journal of the American Society for Mass Spectrometry, Journal Name: Journal of the American Society for Mass Spectrometry Journal Issue: 10 Vol. 17; ISSN 1044-0305; ISSN JAMSEF
- Country of Publication:
- United States
- Language:
- English
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