Ion-Induced Dipole Interactions and Fragmentation Times: Cα-Cβ Chromophore Bond Dissociation Channel.
The fragmentation times corresponding to the loss of the chromophore (Cα-Cβ bond dissociation channel) after photoexcitation at 263 nm have been investigated for several small peptides containing tryptophan or tyrosine. For tryptophan-containing peptides, the aromatic chromophore is lost as an ionic fragment (m/z 130), and the fragmentation time increases with the mass of the neutral fragment. In contrast, for tyrosine-containing peptides the aromatic chromophore is always lost as a neutral fragment (mass = 107 amu) and the fragmentation time is found to be fast (<20 ns). These different behaviors are explained by the role of the postfragmentation interaction in the complex formed after the Cα-Cβ bond cleavage.
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Satchin
S
Soorkia
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Christophe
C
Dehon
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Sunil Kumar
SK
S
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Marie
M
Pérot-Taillandier
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Bruno
B
Lucas
‡Physique des Interactions Ioniques et Moléculaires (PIIM), UMR 7345, CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20, France.
Christophe
C
Jouvet
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Michel
M
Barat
†Institut des Sciences Moléculaires d'Orsay, CNRS UMR 8214, Université Paris Sud, F-91405 Orsay Cedex, France.
Jacqueline A
JA
Fayeton
D007477:Ions / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D055668:Photochemical Processes; D014364:Tryptophan / Q000737:chemistry; D014443:Tyrosine / Q000737:chemistry
D007477:Ions; D010455:Peptides; D014443:Tyrosine; D014364:Tryptophan
UV photodissociation; fragmentation times; ion−induced dipole interactions; peptides; tryptophan; tyrosine