Direct observation of triplet energy transfer between chlorophylls and carotenoids in the core antenna of photosystem I from Thermosynechococcus elongatus.

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F24%3A00604297" target="_blank" >RIV/60077344:_____/24:00604297 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11320/24:10491072 RIV/60076658:12310/24:43908356

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0005272823000622?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0005272823000622?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.bbabio.2023.149016" target="_blank" >10.1016/j.bbabio.2023.149016</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Direct observation of triplet energy transfer between chlorophylls and carotenoids in the core antenna of photosystem I from Thermosynechococcus elongatus.

Popis výsledku v původním jazyce

Quenching of chlorophyll triplet states by carotenoids is an essential photoprotective process, which prevents formation of reactive singlet oxygen in photosynthetic light-harvesting complexes. The process is usually very efficient in oxygenic organisms under physiological conditions, thus preventing any observable accumulation of chlorophyll triplets. However, it subsequently prevents also the determination of the triplet transfer rate. Here we report results of nanosecond transient absorption spectroscopy on photosystem I core complexes, where a major part of chlorophyll a triplet states (similar to 60 %) accumulates on a nanosecond time scale at ambient temperature. As a consequence, the triplet energy transfer could be resolved and the transfer time was determined to be about 24 ns. A smaller fraction of chlorophyll a triplet states (similar to 40 %) is quenched with a faster rate, which could not be determined. Our analysis indicates that these chlorophylls are in direct contact with carotenoids. The overall chlorophyll triplet yield in the core antenna was estimated to be similar to 0.3 %, which is a value two orders of magnitude smaller than in most other photosynthetic light-harvesting complexes. This explains why slower quenching of chlorophyll triplet states is sufficient for photoprotection of photosystem I. Nevertheless, the core antenna of photosystem I represents one of only few photosynthetic complexes of oxygenic organisms in which the quenching rate of the majority of chlorophyll triplets can be directly monitored under physiological temperature.

Název v anglickém jazyce

Direct observation of triplet energy transfer between chlorophylls and carotenoids in the core antenna of photosystem I from Thermosynechococcus elongatus.

Popis výsledku anglicky

Quenching of chlorophyll triplet states by carotenoids is an essential photoprotective process, which prevents formation of reactive singlet oxygen in photosynthetic light-harvesting complexes. The process is usually very efficient in oxygenic organisms under physiological conditions, thus preventing any observable accumulation of chlorophyll triplets. However, it subsequently prevents also the determination of the triplet transfer rate. Here we report results of nanosecond transient absorption spectroscopy on photosystem I core complexes, where a major part of chlorophyll a triplet states (similar to 60 %) accumulates on a nanosecond time scale at ambient temperature. As a consequence, the triplet energy transfer could be resolved and the transfer time was determined to be about 24 ns. A smaller fraction of chlorophyll a triplet states (similar to 40 %) is quenched with a faster rate, which could not be determined. Our analysis indicates that these chlorophylls are in direct contact with carotenoids. The overall chlorophyll triplet yield in the core antenna was estimated to be similar to 0.3 %, which is a value two orders of magnitude smaller than in most other photosynthetic light-harvesting complexes. This explains why slower quenching of chlorophyll triplet states is sufficient for photoprotection of photosystem I. Nevertheless, the core antenna of photosystem I represents one of only few photosynthetic complexes of oxygenic organisms in which the quenching rate of the majority of chlorophyll triplets can be directly monitored under physiological temperature.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

Projekt

<a href="/cs/project/GA20-01159S" target="_blank" >GA20-01159S: Interakce mezi pigmenty pro účinný sběr světla a fotoprotekci ve fotosyntéze</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Biochimica Et Biophysica Acta-Bioenergetics

ISSN

0005-2728

e-ISSN

1879-2650

Svazek periodika

1865

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

7

Strana od-do

149016

Kód UT WoS článku

001163147300001

EID výsledku v databázi Scopus

2-s2.0-85173997569