Reconstitution of the water-oxidizing complex in manganese-depleted photosystem II preparations using synthetic Mn complexes: a fluorine-19 NMR study of the reconstitution process

Nagata, Toshi; Zharmukhamedov, Sergei K.; Khorobrykh, A. A.; Klimov, Vyacheslav V.; Allakhverdiev, Suleyman I.

doi:10.1007/s11120-008-9319-9

Cited by 20 publications

(15 citation statements)

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“…This value remained almost constant, even with the addition of CaCl 2 and MnCl 2 to a titration buffer in the dark or the light. Similarly there was an up-shift of potential to −17 mV with 2-(cyclohexylamino) ethanesulfonic acid (CHES), another Mn cluster-depleting agent (17,18), and a result almost identical to the treatment with NH 2 OH ( Fig. 1C and Table 1).…”

Section: Resultsmentioning

confidence: 76%

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Redox potentials of primary electron acceptor quinone molecule (Q _A ) ⁻ and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Allakhverdiev

Watabe

Kojima

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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In a previous study, we measured the redox potential of the primary electron acceptor pheophytin (Phe) a of photosystem (PS) II in the chlorophyll d-dominated cyanobacterium Acaryochloris marina and a chlorophyll a-containing cyanobacterium, Synechocystis. We obtained the midpoint redox potential (E m ) values of −478 mV for A. marina and −536 mV for Synechocystis. In this study, we measured the redox potentials of the primary electron acceptor quinone molecule (Q A ), i. ) of A. marina was determined to be +64 mV without the Mn cluster and was estimated to be −66 to −86 mV with a Mn-depletion shift (130-150 mV), as observed with other organisms. The E m (Phe a/Phe a − ) in Synechocystis was measured to be −525 mV with the Mn cluster, which is consistent with our previous report. The Mn-depleted downshift of the potential was measured to be approximately −77 mV in Synechocystis, and this value was applied to A. marina (−478 mV); the E m (Phe a/Phe a − ) was estimated to be approximately −401 mV. These values gave rise to a ΔG PhQ of −325 mV for A. marina and −383 mV for Synechocystis. In the two cyanobacteria, the energetics in PS II were conserved, even though the potentials of Q A − and Phe a − were relatively shifted depending on the special pair, indicating a common strategy for electron transfer in oxygenic photosynthetic organisms.photosynthesis | photochemical reaction C hlorophylls (Chls) are key pigments for photosynthesis, and oxygenic photosynthetic organisms containing Chls are found all over the world-they sustain all terrestrial life through the primary production of organic molecules and the production of oxygen. Chl a and its derivatives, pheophytin (Phe) a and Chl a epimer (Chl a′), are used as the electron transfer components in photosystem (PS) II and PS I, respectively, except for in two taxonomic groups, marine cyanobacteria Prochlorococcus spp. containing divinyl-Chl a (1) and marine cyanobacteria Acaryochloris spp. containing Chl d (2). Consequently, experimental and theoretical analyses of the electron transfer system in oxygenic photosynthesis have been exclusively performed in Chl a-containing organisms, and the basic concept of the photosynthetic electron flow has been constructed on the basis of Chl a. However, our understanding of photosynthetic electron transfer is not yet complete because the reaction systems with divinyl-Chl a and Chl d have not been fully analyzed as yet.Since the discovery of Chl d in Acaryochloris marina in 1996 (3, 4), questions have arisen on the whether the electron transfer system in this organism is significantly different from those with Chl a. Interestingly, the functional "special pair" are Chl d molecules in the reaction centers of PS I and II in A. marina (5, 6); however, in PS II, Phe a is the primary electron acceptor. Chl d gains light energy at longer wavelengths and with a lowered redox potential, by ∼80 mV, compared with that of Chl a in Synechocystis sp. PCC 6803 (hereafter referred to as Synechocystis) and spinach (7-11). However, the overall ...

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Section: Resultsmentioning

confidence: 76%

“…Preparation of biochemically treated samples: Mn depletion. To obtain Mndepleted samples, Tris, CHES, and NH 2 OH treatments were performed on PS II complexes isolated from Synechocystis (17)(18)(19)(35)(36)(37). Reconstitution of Mn-depleted PS II complexes.…”

Section: Methodsmentioning

confidence: 99%

Redox potentials of primary electron acceptor quinone molecule (Q _A ) ⁻ and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Allakhverdiev

Watabe

Kojima

et al. 2011

Proc. Natl. Acad. Sci. U.S.A.

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“…In PSII, there are specific intrinsic proteins that appear to be required for water oxidation. These are proteins CP47, CP43, the D1 protein, the D2 protein and the a and b subunits of cytochrome b 559 [11][12][13][14][15][16][17][18][19][69][70][71][72][73][74]. Thus, PSII consists of hundreds of amino acids.…”

Section: Nano-sized Manganese Oxide -Bovine Serum Albuminmentioning

confidence: 99%

“…The only system to catalyse water oxidation in nature is the water-oxidizing complex (WOC) of photosystem II (PSII) in cyanobacteria, algae and plants (figure 1) [11][12][13][14][15][16][17][18][19][20][21][22][23].…”

Section: Introductionmentioning

confidence: 99%

Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review

Najafpour

Rahimi

Aro

et al. 2012

J. R. Soc. Interface.

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129

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There has been a tremendous surge in research on the synthesis of various metal compounds aimed at simulating the water-oxidizing complex (WOC) of photosystem II (PSII). This is crucial because the water oxidation half reaction is overwhelmingly rate-limiting and needs high over-voltage (approx. 1 V), which results in low conversion efficiencies when working at current densities required for hydrogen production via water splitting. Particular attention has been given to the manganese compounds not only because manganese has been used by nature to oxidize water but also because manganese is cheap and environmentally friendly. The manganese-calcium cluster in PSII has a dimension of about approximately 0.5 nm. Thus, nano-sized manganese compounds might be good structural and functional models for the cluster. As in the nanometre-size of the synthetic models, most of the active sites are at the surface, these compounds could be more efficient catalysts than micrometre (or bigger) particles. In this paper, we focus on nano-sized manganese oxides as functional and structural models of the WOC of PSII for hydrogen production via water splitting and review nano-sized manganese oxides used in water oxidation by some research groups.

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“…To develop active and stable catalysts for water oxidation, it is important to use multinuclear structure, which can accumulate and delocalize four oxidizing equivalents. Diand tetra-nuclear manganese complexes as well as mono-, di-, and tri-nuclear ruthenium complexes have been reported as molecular catalysts capable of evolving O 2 from water (Allakhverdiev et al, 1999;Yagi and Kaneko, 2001;Lomoth et al, 2006;McEvoy and Brudvig, 2006;Nagata et al, , 2008. The presence of oxygen at the catalytic site for hydrogen production can inactivate or decrease the performance of the many known catalysts.…”

Section: Introductionmentioning

confidence: 99%

Photosynthetic Energy Conversion: Hydrogen Photoproduction by Natural and Biomimetic Means

Allakhverdiev¹,

Kreslavski²,

Thavasi³

et al. 2010

Biomimetics Learning From Nature

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Reconstitution of the water-oxidizing complex in manganese-depleted photosystem II preparations using synthetic Mn complexes: a fluorine-19 NMR study of the reconstitution process

Cited by 20 publications

References 11 publications

Redox potentials of primary electron acceptor quinone molecule (Q _A ) ⁻ and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Redox potentials of primary electron acceptor quinone molecule (Q _A ) ⁻ and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review

Photosynthetic Energy Conversion: Hydrogen Photoproduction by Natural and Biomimetic Means

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Reconstitution of the water-oxidizing complex in manganese-depleted photosystem II preparations using synthetic Mn complexes: a fluorine-19 NMR study of the reconstitution process

Cited by 20 publications

References 11 publications

Redox potentials of primary electron acceptor quinone molecule (Q A ) − and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Redox potentials of primary electron acceptor quinone molecule (Q A ) − and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Nano-sized manganese oxides as biomimetic catalysts for water oxidation in artificial photosynthesis: a review

Photosynthetic Energy Conversion: Hydrogen Photoproduction by Natural and Biomimetic Means

Contact Info

Product

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Redox potentials of primary electron acceptor quinone molecule (Q _A ) ⁻ and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d

Redox potentials of primary electron acceptor quinone molecule (Q _A ) ⁻ and conserved energetics of photosystem II in cyanobacteria with chlorophyll a and chlorophyll d