UV Excitation of Carotenoid Binding Proteins OCP and HCP: Excited-State Dynamics and Product Formation

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60076658%3A12310%2F22%3A43904805" target="_blank" >RIV/60076658:12310/22:43904805 - isvavai.cz</a>

Výsledek na webu

<a href="https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cptc.202100194" target="_blank" >https://chemistry-europe.onlinelibrary.wiley.com/doi/epdf/10.1002/cptc.202100194</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/cptc.202100194" target="_blank" >10.1002/cptc.202100194</a>

Jazyk výsledku

angličtina

Název v původním jazyce

UV Excitation of Carotenoid Binding Proteins OCP and HCP: Excited-State Dynamics and Product Formation

Popis výsledku v původním jazyce

Over the last decade the orange carotenoid protein (OCP) gained attention due to its role in photoprotection in cyanobacteria. Recently, other carotenoid binding proteins such as helical carotenoid proteins (HCPs) have been identified and characterized, although the function of the HCPs is not yet clarified. Here we have examined OCP1 and two HCPs, HCP2 and HCP3, from Tolypothrix PCC 7601 by ultrafast spectroscopy after excitation of both carotenoid canthaxanthin and amino acids tryptophan and tyrosine in UV at 275 nm. We find that the canthaxanthin S-1 lifetime remains the same 3.5 ps as for excitation of the carotenoid S-2 state, but the S* signal is significantly amplified by UV excitation. In contrast to the S-2 excitation, we observe a formation of the canthaxanthin radical cation at 900 nm for all three proteins after 275 nm excitation. In OCP1, UV light also enhances the amplitude of spectral band centered at 550 nm at longer delays. This band likely corresponds to the first photoproduct of the OCP photocycle, suggesting that excess energy excitation and/or direct excitation of amino acids can enhance the product formation.

Název v anglickém jazyce

UV Excitation of Carotenoid Binding Proteins OCP and HCP: Excited-State Dynamics and Product Formation

Popis výsledku anglicky

Over the last decade the orange carotenoid protein (OCP) gained attention due to its role in photoprotection in cyanobacteria. Recently, other carotenoid binding proteins such as helical carotenoid proteins (HCPs) have been identified and characterized, although the function of the HCPs is not yet clarified. Here we have examined OCP1 and two HCPs, HCP2 and HCP3, from Tolypothrix PCC 7601 by ultrafast spectroscopy after excitation of both carotenoid canthaxanthin and amino acids tryptophan and tyrosine in UV at 275 nm. We find that the canthaxanthin S-1 lifetime remains the same 3.5 ps as for excitation of the carotenoid S-2 state, but the S* signal is significantly amplified by UV excitation. In contrast to the S-2 excitation, we observe a formation of the canthaxanthin radical cation at 900 nm for all three proteins after 275 nm excitation. In OCP1, UV light also enhances the amplitude of spectral band centered at 550 nm at longer delays. This band likely corresponds to the first photoproduct of the OCP photocycle, suggesting that excess energy excitation and/or direct excitation of amino acids can enhance the product formation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

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

2022

Kód důvěrnosti údajů

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

Název periodika

ChemPhotoChem

ISSN

2367-0932

e-ISSN

2367-0932

Svazek periodika

6

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

10

Strana od-do

nestrankovano

Kód UT WoS článku

000711724500001

EID výsledku v databázi Scopus

2-s2.0-85117924530