Excited-State Proton Transfer in Oxyluciferin and its Analogues.
Fiche publication
Date publication
avril 2020
Journal
The journal of physical chemistry letters
Auteurs
Membres identifiés du Cancéropôle Est :
Pr MELY Yves
Tous les auteurs :
Gosset P, Taupier G, Cregut O, Brazard J, Mély Y, Dorkenoo KD, Léonard J, Didier P
Lien Pubmed
Résumé
One of the most characterized bioluminescent reactions involves the firefly luciferase that catalyzes the oxidation of the luciferin producing oxyluciferin in its first excited state. While relaxing to the ground state, oxyluciferin emits visible light with an emission maximum that can vary from green to red. Oxyluciferin exists under six different chemical forms resulting from a keto/enol tautomerization and the deprotonation of the phenol or enol moieties. The optical properties of each chemical form have been recently characterized by the investigations of a variety of oxyluciferin derivatives, indicating unresolved excited-state proton transfer (ESPT) reactions. In this work, femtosecond pump-probe spectroscopy and picosecond-resolved fluorescence are used to investigate the picosecond kinetics of the ESPT reactions and demonstrate the excited state keto to enol conversion of oxyluciferin and its derivatives in aqueous buffer as a function of pH. A comprehensive photophysical scheme is provided describing the complex luminescence pathways of oxyluciferin in protic solution.
Référence
J Phys Chem Lett. 2020 Apr 20;: