Ion-Induced Dipole Interactions and Fragmentation Times : Cα -Cβ Chromophore Bond Dissociation Channel

Satchin Soorkia (1) , Christophe Dehon (1) , Sunil Kumar (1) , Marie Pérot-Taillandier (1) , Bruno Lucas (1) , Christophe Jouvet (2) , Michel Barat (1) , Jacqueline A. Fayeton (1)

1 ISMO - Institut des Sciences Moléculaires d'Orsay
2 PIIM - Physique des interactions ioniques et moléculaires

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.

Mots clés: UV photodissociation; Peptides; Tryptophan; Tyrosine; Fragmentation times; Ion – induced dipole interactions

Domaines: Agrégats Moléculaires et Atomiques [physics.atm-clus]

Satchin Soorkia, Christophe Dehon, Sunil Kumar, Marie Pérot-Taillandier, Bruno Lucas, et al.. Ion-Induced Dipole Interactions and Fragmentation Times : Cα -Cβ Chromophore Bond Dissociation Channel. Journal of Physical Chemistry Letters, 2015, 6, pp.2070. ⟨10.1021/acs.jpclett.5b00792⟩. ⟨hal-01164728⟩