Naslov
UV Photo-dissociation of proline-containing peptide ions : Insights from molecular dynamics

Autori
Girod, Marion ; Sanader, Željka ; Vojković, Marin ; Antoine, Rodolphe ; MacAleese, Luke ; Lemoine, Jérôme ; Bonačić-Koutecky, Vlasta ; Dugourd, Philippe

Izvornik
Journal of the American Society for Mass Spectrometry (1044-0305) 26 (2014), 3; 432-443

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Laser induced dissociation; proline-containing peptides; fragmentation; molecular dynamics; H/D exchange

Sažetak
UV photodissociation of proline-containing peptide ions leads to unusual product ions. In this paper, we report laser-induced dissociation of a series of proline-containing peptides at 213 nm. We observe specific fragmentation pathways corresponding to the formation of (y-2), (a+2) and (b+2) fragment ions. This was not observed at 266 nm or for peptides which do not contain proline residues. In order to obtain insights into the fragmentation dynamics at 213 nm, a small peptide (RPK for arginine-proline-lysine) was studied both theoretically and experimentally. Calculations of absorption spectra and non-adiabatic molecular dynamics (MD) were made. Second and third excited singlet states, S2 and S3, lie close to 213 nm. Non-adiabatic MD simulation starting from S2 and S3 shows that these transitions are followed by C-C and C-N bond activation close to the proline residue. After this first relaxation step, consecutive rearrangements and proton transfers are required to produce unusual (y-2), (a+2) and (b+2) fragment ions. These fragmentation mechanisms were confirmed by H/D exchange experiments.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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