TY - JOUR
T1 - Temperature Controlled Decay and Pendulum Dynamics of Green Fluorescent Protein (GFP) Chromophore
AU - Park, Woojin
AU - Oh, Juwon
AU - Kim, Jinseok
AU - Lee, Seunghoon
AU - Kim, Ji Heon
AU - Huix-Rotllant, Miquel
AU - Kim, Dongho
AU - Choi, Cheol Ho
N1 - Publisher Copyright:
© 2024 American Chemical Society.
PY - 2024/11/21
Y1 - 2024/11/21
N2 - The excited-state dynamics of the GFP chromophore, HBDI- (anionic p-hydroxybenzylidene-2,3-dimethylimidazolinone), were investigated through a combination of theoretical nonadiabatic molecular dynamics (NAMD) simulations and femtosecond transient absorption spectroscopy (fs-TA). The NAMD simulations revealed that the primary dynamics in excited states involve the formation of a P-twisted intermediate (S1min,P), which undergoes pendulum-like oscillations with respect to ϕ = 90°. This motion serves as a reservoir for the excited-state population and the primary source of fluorescence. Rather than a direct channel from the major S1min,P, a coordinated pathway of S1min,P → S1min → S1min,I → S0 is responsible for the decay to the ground state, emphasizing the importance of planar intermediate (S1min) formation. The experimental fs-TA spectra confirmed these dynamics, revealing three distinct time scales (340-470 fs, 1.4 ps, and 8.3 ps), corresponding to the formation of S1min,P and its decay governed by the coordinated pathway. At low temperatures, the coordinated decay pathway is suppressed, leading to prolonged fluorescence lifetimes, consistent with low-temperature experimental results. This study presents a new model for the excited-state dynamics of GFP chromophore, suggesting that pendulum motion and the coordinated decay pathway play a crucial role in regulating fluorescence intensity.
AB - The excited-state dynamics of the GFP chromophore, HBDI- (anionic p-hydroxybenzylidene-2,3-dimethylimidazolinone), were investigated through a combination of theoretical nonadiabatic molecular dynamics (NAMD) simulations and femtosecond transient absorption spectroscopy (fs-TA). The NAMD simulations revealed that the primary dynamics in excited states involve the formation of a P-twisted intermediate (S1min,P), which undergoes pendulum-like oscillations with respect to ϕ = 90°. This motion serves as a reservoir for the excited-state population and the primary source of fluorescence. Rather than a direct channel from the major S1min,P, a coordinated pathway of S1min,P → S1min → S1min,I → S0 is responsible for the decay to the ground state, emphasizing the importance of planar intermediate (S1min) formation. The experimental fs-TA spectra confirmed these dynamics, revealing three distinct time scales (340-470 fs, 1.4 ps, and 8.3 ps), corresponding to the formation of S1min,P and its decay governed by the coordinated pathway. At low temperatures, the coordinated decay pathway is suppressed, leading to prolonged fluorescence lifetimes, consistent with low-temperature experimental results. This study presents a new model for the excited-state dynamics of GFP chromophore, suggesting that pendulum motion and the coordinated decay pathway play a crucial role in regulating fluorescence intensity.
UR - http://www.scopus.com/inward/record.url?scp=85209391680&partnerID=8YFLogxK
U2 - 10.1021/acs.jpclett.4c02761
DO - 10.1021/acs.jpclett.4c02761
M3 - Article
C2 - 39513546
AN - SCOPUS:85209391680
SN - 1948-7185
VL - 15
SP - 11468
EP - 11475
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 46
ER -