New Insights into the Vacuum UV Photodissociation of Peptides.
Vacuum ultraviolet laser photodissociation (UVPD) of peptide ions leads to unusual dissociation channels involving backbone C-C bond breaking. However, the molecular basis for the observed behavior is not clearly understood. We now report theoretical investigations using ab initio/density functional...
| Publicado en: | Journal of the American Chemical Society Vol. 132; no. 5; pp. 1606 - 1611 |
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| Autores principales: | , , , |
| Formato: | Artículo |
| Publicado: |
American Chemical Society
2/10/2010
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| Materias: | |
| Acceso en línea: | Ver este registro en EBSCOhost |
| Sumario: | Vacuum ultraviolet laser photodissociation (UVPD) of peptide ions leads to unusual dissociation channels involving backbone C-C bond breaking. However, the molecular basis for the observed behavior is not clearly understood. We now report theoretical investigations using ab initio/density functional theory (DFT) techniques on neutral and protonated dipeptides undergoing vacuum ultraviolet (VUV) induced fragmentation via a Rydberg excitation (and/or electron detachment) and subsequent C-C bond cleavage. New experimental results on VUV photodissociation of dipeptides (protonated Ala̱Arg and Arg̱Ala) provide strong support for our proposed model. Our mechanism also provides a natural explanation for the presence of immonium ions that are sometimes observed in such experiments. |
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