Ab initio study of the excited-state deactivation pathways of protonated tryptophan and tyrosine.
In recent experiments, the excited-state lifetimes of protonated aromatic amino acids (TrpH+ and TyrH+) have been recorded by means of pump-probe photodissociation technique. The lifetime of TyrH+ is much longer than that of TrpH+, which has been initially rationalized on the basis of a simple phenomenological model. Besides, specific photofragments including the formation of radical cation after hydrogen loss are observed for TrpH+ that are not found for TyrH+. The ab initio calculations reported here for TrpH+ and TyrH+ using a coupled-cluster method are meant to track the rich photochemistry of these protonated amino acids following UV excitation.
Grégoire
Gilles
G
Laboratoire de Physique des Lasers du CNRS, Institut Galilée, Université Paris 13, 93430 Villetaneuse, France. gregoire@lpl.univ-paris13.fr
Jouvet
Christophe
C
Dedonder
Claude
C
Sobolewski
Andrzej L
AL
D007536:Isomerism; D008958:Models, Molecular; D010777:Photochemistry; D011522:Protons; D013816:Thermodynamics; D014364:Tryptophan / Q000737:chemistry*; D014443:Tyrosine / Q000737:chemistry*; D014466:Ultraviolet Rays
D011522:Protons; D014443:Tyrosine; D014364:Tryptophan