Open AccessTurning On and Off Photoinduced Electron Transfer in Fluorescent Proteins by π-Stacking, Halide Binding, and Tyr145 Mutations
Author(s) -
Alexey M. Bogdanov,
Atanu Acharya,
Anastasia V. Titelmayer,
Anastasia V. Mamontova,
Ksenia B. Bravaya,
Anatoly B. Kolomeisky,
Konstantin A. Lukyanov,
Anna I. Krylov
Publication year - 2016
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.6b00092
Subject(s) - chemistry , chromophore , electron transfer , stacking , photochemistry , fluorescence , photoinduced electron transfer , green fluorescent protein , excited state , electron acceptor , point mutation , halide , mutant , electron transport chain , biophysics , biochemistry , gene , organic chemistry , physics , quantum mechanics , biology , nuclear physics
Photoinduced electron transfer in fluorescent proteins from the GFP family can be regarded either as an asset facilitating new applications or as a nuisance leading to the loss of optical output. Photooxidation commonly results in green-to-red photoconversion called oxidative redding. We discovered that yellow FPs do not undergo redding; however, the redding is restored upon halide binding. Calculations of the energetics of one-electron oxidation and possible electron transfer (ET) pathways suggested that excited-state ET proceeds through a hopping mechanism via Tyr145. In YFPs, the π-stacking of the chromophore with Tyr203 reduces its electron-donating ability, which can be restored by halide binding. Point mutations confirmed that Tyr145 is a key residue controlling ET. Substitution of Tyr145 by less-efficient electron acceptors resulted in highly photostable mutants. This strategy (i.e., calculation and disruption of ET pathways by mutations) may represent a new approach toward enhancing photostability of FPs.