Triplet state quenching of bacteriochlorophyll c aggregates in a protein-free environment of a chlorosome interior

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12310%2F20%3A43901163" target="_blank" >RIV/60076658:12310/20:43901163 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/60077344:_____/20:00517107 RIV/61388955:_____/20:00517107 RIV/00216208:11320/20:10404684

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0301010419305920?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0301010419305920?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.chemphys.2019.110542" target="_blank" >10.1016/j.chemphys.2019.110542</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Triplet state quenching of bacteriochlorophyll c aggregates in a protein-free environment of a chlorosome interior

Popis výsledku v původním jazyce

Efficient quenching of (bacterio)chlorophyll triplet states by carotenoids prevents formation of reactive singlet oxygen in photosynthetic light-harvesting complexes. This protective process requires a close interaction between both types of pigments, which is usually ensured by a protein scaffold. Here we have studied quenching of bacteriochlorophyll c triplets in chlorosomes from the green photosynthetic bacterium Chloroflexus aurantiacus by nanosecond spectroscopy. Bacteriochlorophyll c forms aggregates in the chlorosome interior without involvement of a protein. We have observed that the triplet transfer from bacteriochlorophyll aggregates to carotenoids occurs with a transfer time of approximately 4 ns, being more than ten times slower that the estimates for the fastest triplet quenching in pigment-protein light-harvesting complexes. Nevertheless, together with aggregation-mediated shortening of excited state lifetimes, carotenoids provide efficient protection against formation of singlet oxygen in chlorosomes. Efficient triplet quenching was also observed in self-assembling, artificial light-harvesting complexes containing bacteriochlorophyll c aggregates and beta-carotene. This is important for their future applications in solar energy conversion. Finally, we have studied the temperature dependence of triplet quenching in chlorosomes and determined the activation energy of the energy transfer to be about 0.08 eV. This value lies within the range estimated for pigment-protein light-harvesting complexes.

Název v anglickém jazyce

Triplet state quenching of bacteriochlorophyll c aggregates in a protein-free environment of a chlorosome interior

Popis výsledku anglicky

Efficient quenching of (bacterio)chlorophyll triplet states by carotenoids prevents formation of reactive singlet oxygen in photosynthetic light-harvesting complexes. This protective process requires a close interaction between both types of pigments, which is usually ensured by a protein scaffold. Here we have studied quenching of bacteriochlorophyll c triplets in chlorosomes from the green photosynthetic bacterium Chloroflexus aurantiacus by nanosecond spectroscopy. Bacteriochlorophyll c forms aggregates in the chlorosome interior without involvement of a protein. We have observed that the triplet transfer from bacteriochlorophyll aggregates to carotenoids occurs with a transfer time of approximately 4 ns, being more than ten times slower that the estimates for the fastest triplet quenching in pigment-protein light-harvesting complexes. Nevertheless, together with aggregation-mediated shortening of excited state lifetimes, carotenoids provide efficient protection against formation of singlet oxygen in chlorosomes. Efficient triplet quenching was also observed in self-assembling, artificial light-harvesting complexes containing bacteriochlorophyll c aggregates and beta-carotene. This is important for their future applications in solar energy conversion. Finally, we have studied the temperature dependence of triplet quenching in chlorosomes and determined the activation energy of the energy transfer to be about 0.08 eV. This value lies within the range estimated for pigment-protein light-harvesting complexes.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

<a href="/cs/project/GX19-28323X" target="_blank" >GX19-28323X: Vztah mezi strukturou a funkcí karotenoidů: Nové cesty k řešení nezodpovězených otázek</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

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

Název periodika

Chemical Physics

ISSN

0301-0104

e-ISSN

—

Svazek periodika

529

Číslo periodika v rámci svazku

JAN 15 2020

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

7

Strana od-do

—

Kód UT WoS článku

000498052700002

EID výsledku v databázi Scopus

2-s2.0-85072961984