Temperature Dependence of Chlorophyll Triplet Quenching in Two Photosynthetic Light-Harvesting Complexes from Higher Plants and Dinoflagellates

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F18%3A10384569" target="_blank" >RIV/00216208:11320/18:10384569 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1021/acs.jpcb.8b06751" target="_blank" >https://doi.org/10.1021/acs.jpcb.8b06751</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1021/acs.jpcb.8b06751" target="_blank" >10.1021/acs.jpcb.8b06751</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Temperature Dependence of Chlorophyll Triplet Quenching in Two Photosynthetic Light-Harvesting Complexes from Higher Plants and Dinoflagellates

Popis výsledku v původním jazyce

Chlorophyll (Chl) triplet states generated in photosynthetic light-harvesting complexes (LHCs) can be quenched by carotenoids to prevent the formation of reactive singlet oxygen. Although this quenching occurs with an efficiency close to 100% at physiological temperatures, the Chl triplets are often observed at low temperatures. This might be due to the intrinsic temperature dependence of the Dexter mechanism of excitation energy transfer, which governs triplet quenching, or by temperature-induced conformational changes. Here, we report about the temperature dependence of Chl triplet quenching in two LHCs. We show that both the effects contribute significantly. In LHC II of higher plants, the core Chls are quenched with a high efficiency independent of temperature. A different subpopulation of Chls, which increases with lowering temperature, is not quenched at all. This is probably caused by the conformational changes which detach these Chls from the energy-transfer chain. In a membrane-intrinsic LHC of dinoflagellates, similarly two subpopulations of Chls were observed. In addition, another part of Chl triplets is quenched by carotenoids with a rate which decreases with temperature. This allowed us to study the temperature dependence of Dexter energy transfer. Finally, a part of Chls was quenched by triplet-triplet annihilation, a phenomenon which was not observed for LHCs before.

Název v anglickém jazyce

Temperature Dependence of Chlorophyll Triplet Quenching in Two Photosynthetic Light-Harvesting Complexes from Higher Plants and Dinoflagellates

Popis výsledku anglicky

Chlorophyll (Chl) triplet states generated in photosynthetic light-harvesting complexes (LHCs) can be quenched by carotenoids to prevent the formation of reactive singlet oxygen. Although this quenching occurs with an efficiency close to 100% at physiological temperatures, the Chl triplets are often observed at low temperatures. This might be due to the intrinsic temperature dependence of the Dexter mechanism of excitation energy transfer, which governs triplet quenching, or by temperature-induced conformational changes. Here, we report about the temperature dependence of Chl triplet quenching in two LHCs. We show that both the effects contribute significantly. In LHC II of higher plants, the core Chls are quenched with a high efficiency independent of temperature. A different subpopulation of Chls, which increases with lowering temperature, is not quenched at all. This is probably caused by the conformational changes which detach these Chls from the energy-transfer chain. In a membrane-intrinsic LHC of dinoflagellates, similarly two subpopulations of Chls were observed. In addition, another part of Chl triplets is quenched by carotenoids with a rate which decreases with temperature. This allowed us to study the temperature dependence of Dexter energy transfer. Finally, a part of Chls was quenched by triplet-triplet annihilation, a phenomenon which was not observed for LHCs before.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

Projekt

<a href="/cs/project/GBP501%2F12%2FG055" target="_blank" >GBP501/12/G055: Centrum fotosyntetického výzkumu</a><br>

Návaznosti

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

Rok uplatnění

2018

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

—

Svazek periodika

122

Číslo periodika v rámci svazku

38

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

8834-8845

Kód UT WoS článku

000446141600007

EID výsledku v databázi Scopus

2-s2.0-85053698941