Primary donor triplet states of Photosystem I and II studied by Q-band pulse ENDOR spectroscopy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60077344%3A_____%2F22%3A00568733" target="_blank" >RIV/60077344:_____/22:00568733 - isvavai.cz</a>

Výsledek na webu

<a href="https://link.springer.com/article/10.1007/s11120-022-00905-y" target="_blank" >https://link.springer.com/article/10.1007/s11120-022-00905-y</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s11120-022-00905-y" target="_blank" >10.1007/s11120-022-00905-y</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Primary donor triplet states of Photosystem I and II studied by Q-band pulse ENDOR spectroscopy

Popis výsledku v původním jazyce

The photoexcited triplet state of the 'primary donors' in the two photosystems of oxygenic photosynthesis has been investigated by means of electron-nuclear double resonance (ENDOR) at Q-band (34 GHz). The data obtained represent the first set of H-1 hyperfine coupling tensors of the (3)P700 triplet state in PSI and expand the existing data set for (3)P680. We achieved an extensive assignment of the observed electron-nuclear hyperfine coupling constants (hfcs) corresponding to the methine alpha-protons and the methyl group beta-protons of the chlorophyll (Chl) macrocycle. The data clearly confirm that in both photosystems the primary donor triplet is located on one specific monomeric Chl at cryogenic temperature. In comparison to previous transient ENDOR and pulse ENDOR experiments at standard X-band (9-10 GHz), the pulse Q-band ENDOR spectra demonstrate both improved signal-to-noise ratio and increased resolution. The observed ENDOR spectra for (3)P700 and (3)P680 differ in terms of the intensity loss of lines from specific methyl group protons, which is explained by hindered methyl group rotation produced by binding site effects. Contact analysis of the methyl groups in the PSI crystal structure in combination with the ENDOR analysis of (3)P700 suggests that the triplet is located on the Chl aMODIFIER LETTER PRIME (P-A) in PSI. The results also provide additional evidence for the localization of (3)P680 on the accessory Chl(D1) in PSII.

Název v anglickém jazyce

Primary donor triplet states of Photosystem I and II studied by Q-band pulse ENDOR spectroscopy

Popis výsledku anglicky

The photoexcited triplet state of the 'primary donors' in the two photosystems of oxygenic photosynthesis has been investigated by means of electron-nuclear double resonance (ENDOR) at Q-band (34 GHz). The data obtained represent the first set of H-1 hyperfine coupling tensors of the (3)P700 triplet state in PSI and expand the existing data set for (3)P680. We achieved an extensive assignment of the observed electron-nuclear hyperfine coupling constants (hfcs) corresponding to the methine alpha-protons and the methyl group beta-protons of the chlorophyll (Chl) macrocycle. The data clearly confirm that in both photosystems the primary donor triplet is located on one specific monomeric Chl at cryogenic temperature. In comparison to previous transient ENDOR and pulse ENDOR experiments at standard X-band (9-10 GHz), the pulse Q-band ENDOR spectra demonstrate both improved signal-to-noise ratio and increased resolution. The observed ENDOR spectra for (3)P700 and (3)P680 differ in terms of the intensity loss of lines from specific methyl group protons, which is explained by hindered methyl group rotation produced by binding site effects. Contact analysis of the methyl groups in the PSI crystal structure in combination with the ENDOR analysis of (3)P700 suggests that the triplet is located on the Chl aMODIFIER LETTER PRIME (P-A) in PSI. The results also provide additional evidence for the localization of (3)P680 on the accessory Chl(D1) in PSII.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10610 - Biophysics

Projekt

<a href="/cs/project/EF18_053%2F0016982" target="_blank" >EF18_053/0016982: Mezinárodní mobility výzkumných a administrativních pracovníků Biologického centra</a><br>

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

Photosynthesis Research

ISSN

0166-8595

e-ISSN

1573-5079

Svazek periodika

152

Číslo periodika v rámci svazku

2

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

22

Strana od-do

213-234

Kód UT WoS článku

000769264600001

EID výsledku v databázi Scopus

2-s2.0-85126294903