Low-temperature electron transfer suggests two types of QA in intact photosystem II

Han Bao; Chunxi Zhang; Yanan Ren; Jingquan Zhao

doi:10.1016/j.bbabio.2009.12.001

Low-temperature electron transfer suggests two types of Q_A in intact photosystem II

Han Bao, Chunxi Zhang, Yanan Ren, Jingquan Zhao

Research output: Contribution to journal › Article › peer-review

9 Scopus citations

Abstract

The correlation between the reduction of Q_A and the oxidation of Tyr_Z or Car/Chl_Z/Cyt_b559 in spinach PSII enriched membranes induced by visible light at 10 K is studied by using electron paramagnetic resonance spectroscopy. Similar g=1.95-1.86 Q_A^-•EPR signals are observed in both Mn-depleted and intact samples, and both signals are long lived at low temperatures. The presence of PPBQ significantly diminished the light induced EPR signals from Q_A^-•, Car^+•/Chl^+• and oxidized Cyt_b559, while enhancing the amplitude of the S₁Tyr_Z• EPR signal in the intact PSII sample. The quantification and stability of the g=1.95-1.86 EPR signal and signals arising from the oxidized Tyr_Z and the side-path electron donors, respectively, indicate that the EPR-detectable g=1.95-1.86 Q_A^-• signal is only correlated to reaction centers undergoing oxidation of the side-path electron donors (Car/Chl_Z/Cyt_b559), but not of Tyr_Z. These results imply that two types of Q_A^-• probably exist in the intact PSII sample. The structural difference and possible function of the two types of Q_A are discussed.

Original language	English (US)
Pages (from-to)	339-346
Number of pages	8
Journal	Biochimica et Biophysica Acta - Bioenergetics
Volume	1797
Issue number	3
DOIs	https://doi.org/10.1016/j.bbabio.2009.12.001
State	Published - Mar 2010
Externally published	Yes

Bibliographical note

Funding Information:
This work was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China with No. 20403024 , 30570423 , 20973186 . CZ would like to thank Prof. Yandao Gong for help with the oxygen evolution measurement, and thanks to Dr. Jie Pan for carefully reading the manuscript and making valuable comments on it.

Keywords

EPR
Electron transfer
Photosystem II
Q
Side-path electron donor
TyrZ

Publisher link

10.1016/j.bbabio.2009.12.001

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@article{63886bea2634429986b264eb2b93b236,

title = "Low-temperature electron transfer suggests two types of QA in intact photosystem II",

abstract = "The correlation between the reduction of QA and the oxidation of TyrZ or Car/ChlZ/Cytb559 in spinach PSII enriched membranes induced by visible light at 10 K is studied by using electron paramagnetic resonance spectroscopy. Similar g=1.95-1.86 QA-•EPR signals are observed in both Mn-depleted and intact samples, and both signals are long lived at low temperatures. The presence of PPBQ significantly diminished the light induced EPR signals from QA-•, Car+•/Chl+• and oxidized Cytb559, while enhancing the amplitude of the S1TyrZ• EPR signal in the intact PSII sample. The quantification and stability of the g=1.95-1.86 EPR signal and signals arising from the oxidized TyrZ and the side-path electron donors, respectively, indicate that the EPR-detectable g=1.95-1.86 QA-• signal is only correlated to reaction centers undergoing oxidation of the side-path electron donors (Car/ChlZ/Cytb559), but not of TyrZ. These results imply that two types of QA-• probably exist in the intact PSII sample. The structural difference and possible function of the two types of QA are discussed.",

keywords = "EPR, Electron transfer, Photosystem II, Q, Side-path electron donor, TyrZ",

author = "Han Bao and Chunxi Zhang and Yanan Ren and Jingquan Zhao",

note = "Funding Information: This work was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China with No. 20403024 , 30570423 , 20973186 . CZ would like to thank Prof. Yandao Gong for help with the oxygen evolution measurement, and thanks to Dr. Jie Pan for carefully reading the manuscript and making valuable comments on it.",

year = "2010",

month = mar,

doi = "10.1016/j.bbabio.2009.12.001",

language = "English (US)",

volume = "1797",

pages = "339--346",

journal = "Biochimica et Biophysica Acta - Bioenergetics",

issn = "0005-2728",

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number = "3",

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TY - JOUR

T1 - Low-temperature electron transfer suggests two types of QA in intact photosystem II

AU - Bao, Han

AU - Zhang, Chunxi

AU - Ren, Yanan

AU - Zhao, Jingquan

N1 - Funding Information: This work was supported by the Chinese Academy of Sciences and the National Natural Science Foundation of China with No. 20403024 , 30570423 , 20973186 . CZ would like to thank Prof. Yandao Gong for help with the oxygen evolution measurement, and thanks to Dr. Jie Pan for carefully reading the manuscript and making valuable comments on it.

PY - 2010/3

Y1 - 2010/3

N2 - The correlation between the reduction of QA and the oxidation of TyrZ or Car/ChlZ/Cytb559 in spinach PSII enriched membranes induced by visible light at 10 K is studied by using electron paramagnetic resonance spectroscopy. Similar g=1.95-1.86 QA-•EPR signals are observed in both Mn-depleted and intact samples, and both signals are long lived at low temperatures. The presence of PPBQ significantly diminished the light induced EPR signals from QA-•, Car+•/Chl+• and oxidized Cytb559, while enhancing the amplitude of the S1TyrZ• EPR signal in the intact PSII sample. The quantification and stability of the g=1.95-1.86 EPR signal and signals arising from the oxidized TyrZ and the side-path electron donors, respectively, indicate that the EPR-detectable g=1.95-1.86 QA-• signal is only correlated to reaction centers undergoing oxidation of the side-path electron donors (Car/ChlZ/Cytb559), but not of TyrZ. These results imply that two types of QA-• probably exist in the intact PSII sample. The structural difference and possible function of the two types of QA are discussed.

AB - The correlation between the reduction of QA and the oxidation of TyrZ or Car/ChlZ/Cytb559 in spinach PSII enriched membranes induced by visible light at 10 K is studied by using electron paramagnetic resonance spectroscopy. Similar g=1.95-1.86 QA-•EPR signals are observed in both Mn-depleted and intact samples, and both signals are long lived at low temperatures. The presence of PPBQ significantly diminished the light induced EPR signals from QA-•, Car+•/Chl+• and oxidized Cytb559, while enhancing the amplitude of the S1TyrZ• EPR signal in the intact PSII sample. The quantification and stability of the g=1.95-1.86 EPR signal and signals arising from the oxidized TyrZ and the side-path electron donors, respectively, indicate that the EPR-detectable g=1.95-1.86 QA-• signal is only correlated to reaction centers undergoing oxidation of the side-path electron donors (Car/ChlZ/Cytb559), but not of TyrZ. These results imply that two types of QA-• probably exist in the intact PSII sample. The structural difference and possible function of the two types of QA are discussed.

KW - EPR

KW - Electron transfer

KW - Photosystem II

KW - Q

KW - Side-path electron donor

KW - TyrZ

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JO - Biochimica et Biophysica Acta - Bioenergetics

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