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UV Excited‐State Photoresponse of Biochromophore Negative Ions
Author(s) -
Bochenkova Anastasia V.,
Klærke Benedikte,
Rahbek Dennis B.,
Rajput Jyoti,
Toker Yoni,
Andersen Lars H.
Publication year - 2014
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201404609
Subject(s) - chromophore , photochemistry , green fluorescent protein , excited state , electron transfer , chemistry , fluorescence , ion , redox , singlet state , atomic physics , inorganic chemistry , physics , biochemistry , organic chemistry , quantum mechanics , gene
Members of the green fluorescent protein (GFP) family may undergo irreversible phototransformation upon irradiation with UV light. This provides clear evidence for the importance of the higher‐energy photophysics of the chromophore, which remains essentially unexplored. By using time‐resolved action and photoelectron spectroscopy together with high‐level electronic structure theory, we directly probe and identify higher electronically excited singlet states of the isolated para ‐ and meta ‐chromophore anions of GFP. These molecular resonances are found to serve as a doorway for very efficient electron detachment in the gas phase. Inside the protein, this band is found to be resonant with the quasicontinuum of a solvated electron, thus enhancing electron transfer from the GFP to the solvent. This suggests a photophysical pathway for photoconversion of the protein, where GFP resonant photooxidation in solution triggers radical redox reactions inside these proteins.