Phasor Analysis Reveals Multicomponent Fluorescence Kinetics in the LH2 Complex from Marichromatium purpuratum

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388971%3A_____%2F22%3A00565868" target="_blank" >RIV/61388971:_____/22:00565868 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.acs.org/doi/10.1021/acs.jpcb.2c04983" target="_blank" >https://pubs.acs.org/doi/10.1021/acs.jpcb.2c04983</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcb.2c04983" target="_blank" >10.1021/acs.jpcb.2c04983</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Phasor Analysis Reveals Multicomponent Fluorescence Kinetics in the LH2 Complex from Marichromatium purpuratum

Popis výsledku v původním jazyce

We investigated the fluorescence kinetics of LH2 complexes from Marichromatium purpuratum, the cryo-EM structure of which has been recently elucidated with 2.4 Å resolution. The experiments have been carried out as a function of the excitation density by varying both the excitation fluence and the repetition rate of the laser excitation. Instead of the usual multiexponential fitting procedure, we applied the less common phasor formalism for evaluating the transients because this allows for a model-free analysis of the data without a priori knowledge about the number of processes that contribute to a particular decay. For the various excitation conditions, this analysis reproduces consistently three lifetime components with decay times below 100 ps, 500 ps, and 730 ps, which were associated with the quenched state, singlet-triplet annihilation, and fluorescence decay, respectively. Moreover, it reveals that the number of decay components that contribute to the transients depends on whether the excitation wavelength is in resonance with the B800 BChl a molecules or with the carotenoids. Based on the mutual arrangement of the chromophores in their binding pockets, this leads us to conclude that the energy transfer pathways within the LH2 complex of this species differ significantly from each other for exciting either the B800 BChl molecules or the carotenoids. Finally, we speculate whether the illumination with strong laser light converts the LH2 complexes studied here into a quenched conformation that might be related to the development of the non-photochemical quenching mechanism that occurs in higher plants.

Název v anglickém jazyce

Phasor Analysis Reveals Multicomponent Fluorescence Kinetics in the LH2 Complex from Marichromatium purpuratum

Popis výsledku anglicky

We investigated the fluorescence kinetics of LH2 complexes from Marichromatium purpuratum, the cryo-EM structure of which has been recently elucidated with 2.4 Å resolution. The experiments have been carried out as a function of the excitation density by varying both the excitation fluence and the repetition rate of the laser excitation. Instead of the usual multiexponential fitting procedure, we applied the less common phasor formalism for evaluating the transients because this allows for a model-free analysis of the data without a priori knowledge about the number of processes that contribute to a particular decay. For the various excitation conditions, this analysis reproduces consistently three lifetime components with decay times below 100 ps, 500 ps, and 730 ps, which were associated with the quenched state, singlet-triplet annihilation, and fluorescence decay, respectively. Moreover, it reveals that the number of decay components that contribute to the transients depends on whether the excitation wavelength is in resonance with the B800 BChl a molecules or with the carotenoids. Based on the mutual arrangement of the chromophores in their binding pockets, this leads us to conclude that the energy transfer pathways within the LH2 complex of this species differ significantly from each other for exciting either the B800 BChl molecules or the carotenoids. Finally, we speculate whether the illumination with strong laser light converts the LH2 complexes studied here into a quenched conformation that might be related to the development of the non-photochemical quenching mechanism that occurs in higher plants.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10606 - Microbiology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Physical Chemistry B

ISSN

1520-6106

e-ISSN

1520-5207

Svazek periodika

126

Číslo periodika v rámci svazku

49

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

10335-10346

Kód UT WoS článku

000892101000001

EID výsledku v databázi Scopus

2-s2.0-85143505150