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The Effect of Removal of External Proteins PsbO, PsbP and PsbQ on Flash-Induced Molecular Oxygen Evolution and Its Biphasicity in Tobacco PSII

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Publisher MDPI
Specialty Molecular Biology
Date 2024 Jul 26
PMID 39057069
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Abstract

The oxygen evolution within photosystem II (PSII) is one of the most enigmatic processes occurring in nature. It is suggested that external proteins surrounding the oxygen-evolving complex (OEC) not only stabilize it and provide an appropriate ionic environment but also create water channels, which could be involved in triggering the ingress of water and the removal of O and protons outside the system. To investigate the influence of these proteins on the rate of oxygen release and the efficiency of OEC function, we developed a measurement protocol for the direct measurement of the kinetics of oxygen release from PSII using a Joliot-type electrode. PSII-enriched tobacco thylakoids were used in the experiments. The results revealed the existence of slow and fast modes of oxygen evolution. This observation is model-independent and requires no specific assumptions about the initial distribution of the OEC states. The gradual removal of exogenous proteins resulted in a slowdown of the rapid phase (~ms) of O release and its gradual disappearance while the slow phase (~tens of ms) accelerated. The role of external proteins in regulating the biphasicity and efficiency of oxygen release is discussed based on observed phenomena and current knowledge.

References
1.
Pushkar Y, Ravari A, Jensen S, Palenik M . Early Binding of Substrate Oxygen Is Responsible for a Spectroscopically Distinct S State in Photosystem II. J Phys Chem Lett. 2019; 10(17):5284-5291. DOI: 10.1021/acs.jpclett.9b01255. View

2.
Zhang B, Sun L . Why nature chose the MnCaO cluster as water-splitting catalyst in photosystem II: a new hypothesis for the mechanism of O-O bond formation. Dalton Trans. 2018; 47(41):14381-14387. DOI: 10.1039/c8dt01931b. View

3.
Vogt L, Vinyard D, Khan S, Brudvig G . Oxygen-evolving complex of Photosystem II: an analysis of second-shell residues and hydrogen-bonding networks. Curr Opin Chem Biol. 2015; 25:152-8. DOI: 10.1016/j.cbpa.2014.12.040. View

4.
Amin M, Askerka M, Batista V, Brudvig G, Gunner M . X-ray Free Electron Laser Radiation Damage through the S-State Cycle of the Oxygen-Evolving Complex of Photosystem II. J Phys Chem B. 2017; 121(40):9382-9388. DOI: 10.1021/acs.jpcb.7b08371. View

5.
Ogata K, Yuki T, Hatakeyama M, Uchida W, Nakamura S . All-atom molecular dynamics simulation of photosystem II embedded in thylakoid membrane. J Am Chem Soc. 2013; 135(42):15670-3. DOI: 10.1021/ja404317d. View