| Autor: |
Girod M; Université de Lyon, F-69622, Lyon, France, marion.girod@univ-lyon1.fr., Sanader Z, Vojkovic M, Antoine R, MacAleese L, Lemoine J, Bonacic-Koutecky V, Dugourd P |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of the American Society for Mass Spectrometry [J Am Soc Mass Spectrom] 2015 Mar; Vol. 26 (3), pp. 432-43. Date of Electronic Publication: 2014 Dec 11. |
| DOI: |
10.1007/s13361-014-1038-1 |
| Abstrakt: |
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, S(2) and S(3), lie close to 213 nm. Non-adiabatic MD simulation starting from S(2) and S(3) 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. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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