1
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Krysiak S, Burda K. The Effect of Removal of External Proteins PsbO, PsbP and PsbQ on Flash-Induced Molecular Oxygen Evolution and Its Biphasicity in Tobacco PSII. Curr Issues Mol Biol 2024; 46:7187-7218. [PMID: 39057069 PMCID: PMC11276211 DOI: 10.3390/cimb46070428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 06/30/2024] [Accepted: 07/02/2024] [Indexed: 07/28/2024] Open
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 O2 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 O2 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.
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Affiliation(s)
| | - Kvetoslava Burda
- Faculty of Physics and Applied Computer Science, AGH University of Krakow, al. Mickiewicza 30, 30-059 Krakow, Poland;
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2
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Sheth S, Gotico P, Herrero C, Quaranta A, Aukauloo A, Leibl W. Proton Domino Reactions at an Imidazole Relay Control the Oxidation of a Tyr Z-His 190 Artificial Mimic of Photosystem II. Chemistry 2024; 30:e202400862. [PMID: 38676548 DOI: 10.1002/chem.202400862] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/10/2024] [Accepted: 04/24/2024] [Indexed: 04/29/2024]
Abstract
A close mimic of P680 and the TyrosineZ-Histidine190 pair in photosystem II (PS II) has been synthesized using a ruthenium chromophore and imidazole-phenol ligands. The intramolecular oxidation of the ligands by the photoproduced Ru(III) species is characterized by a small driving force, very similar to PS II where the complexity of kinetics was attributed to the reversibility of electron transfer steps. Laser flash photolysis revealed biphasic kinetics for ligand oxidation. The fast phase (τ<50 ns) corresponds to partial oxidation of the imidazole-phenol ligand, proton transfer within the hydrogen bond, and formation of a neutral phenoxyl radical. The slow phase (5-9 μs) corresponds to full oxidation of the ligand which is kinetically controlled by deprotonation of the distant 1-nitrogen of the imidazolium. These results show that imidazole with its two protonatable sites plays a special role as a proton relay in a 'proton domino' reaction.
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Affiliation(s)
- Sujitraj Sheth
- CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris Saclay, 91198, Gif-sur-Yvette, France
- Current affiliation , National Key Laboratory of Green Pesticide, Guizhou University, Guiyang, 550025, Guizhou, China
| | - Philipp Gotico
- CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris Saclay, 91198, Gif-sur-Yvette, France
| | - Christian Herrero
- CNRS, Institut de Chimie Moléculaire et Des Matériaux d'Orsay (ICMMO), Université Paris Saclay, 91405, Orsay, France
| | - Annamaria Quaranta
- CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris Saclay, 91198, Gif-sur-Yvette, France
| | - Ally Aukauloo
- CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris Saclay, 91198, Gif-sur-Yvette, France
- CNRS, Institut de Chimie Moléculaire et Des Matériaux d'Orsay (ICMMO), Université Paris Saclay, 91405, Orsay, France
| | - Winfried Leibl
- CEA, CNRS, Institut de Biologie Intégrative de la Cellule (I2BC), Université Paris Saclay, 91198, Gif-sur-Yvette, France
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3
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Tamura H, Saito K, Nishio S, Ishikita H. Electron-Transfer Route in the Early Oxidation States of the Mn 4CaO 5 Cluster in Photosystem II. J Phys Chem B 2023; 127:205-211. [PMID: 36542840 PMCID: PMC9841979 DOI: 10.1021/acs.jpcb.2c08246] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/07/2022] [Indexed: 12/24/2022]
Abstract
The electron transfer from the oxygen-evolving Mn4CaO5 cluster to the electron acceptor D1-Tyr161 (TyrZ) is a prerequisite for water oxidation and O2 evolution. Here, we analyzed the electronic coupling in the rate-limiting electron-transfer transitions using a combined quantum mechanical/molecular mechanical/polarizable continuum model approach. In the S0 to S1 transition, the electronic coupling between the electron-donor Mn3(III) and TyrZ is small (2 meV). In contrast, the electronic coupling between the dangling Mn4(III) and TyrZ is significantly large (172 meV), which suggests that the electron transfer proceeds from Mn3(III) to TyrZ via Mn4(III). In the S1 to S2 transition, the electronic coupling between Mn4(III) and TyrZ is also larger (124 meV) than that between Mn1(III) and TyrZ (1 meV), which favors the formation of the open-cubane S2 conformation with Mn4(IV) over the formation of the closed-cubane S2 conformation with Mn1(IV). In the S0 to S1 and S1 to S2 transitions, the Mn4 d-orbital and the TyrZ π-orbital are hybridized via D1-Asp170, which suggests that D1-Asp170 commonly provides a dominant electron-transfer route.
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Affiliation(s)
- Hiroyuki Tamura
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo153-8904, Japan
| | - Keisuke Saito
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo153-8904, Japan
| | - Shunya Nishio
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo153-8904, Japan
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4
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Sirohiwal A, Pantazis DA. Functional Water Networks in Fully Hydrated Photosystem II. J Am Chem Soc 2022; 144:22035-22050. [PMID: 36413491 PMCID: PMC9732884 DOI: 10.1021/jacs.2c09121] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Water channels and networks within photosystem II (PSII) of oxygenic photosynthesis are critical for enzyme structure and function. They control substrate delivery to the oxygen-evolving center and mediate proton transfer at both the oxidative and reductive endpoints. Current views on PSII hydration are derived from protein crystallography, but structural information may be compromised by sample dehydration and technical limitations. Here, we simulate the physiological hydration structure of a cyanobacterial PSII model following a thorough hydration procedure and large-scale unconstrained all-atom molecular dynamics enabled by massively parallel simulations. We show that crystallographic models of PSII are moderately to severely dehydrated and that this problem is particularly acute for models derived from X-ray free electron laser (XFEL) serial femtosecond crystallography. We present a fully hydrated representation of cyanobacterial PSII and map all water channels, both static and dynamic, associated with the electron donor and acceptor sides. Among them, we describe a series of transient channels and the attendant conformational gating role of protein components. On the acceptor side, we characterize a channel system that is absent from existing crystallographic models but is likely functionally important for the reduction of the terminal electron acceptor plastoquinone QB. The results of the present work build a foundation for properly (re)evaluating crystallographic models and for eliciting new insights into PSII structure and function.
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5
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Imaizumi K, Ifuku K. Binding and functions of the two chloride ions in the oxygen-evolving center of photosystem II. PHOTOSYNTHESIS RESEARCH 2022; 153:135-156. [PMID: 35698013 DOI: 10.1007/s11120-022-00921-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 05/02/2022] [Indexed: 06/15/2023]
Abstract
Light-driven water oxidation in photosynthesis occurs at the oxygen-evolving center (OEC) of photosystem II (PSII). Chloride ions (Cl-) are essential for oxygen evolution by PSII, and two Cl- ions have been found to specifically bind near the Mn4CaO5 cluster in the OEC. The retention of these Cl- ions within the OEC is critically supported by some of the membrane-extrinsic subunits of PSII. The functions of these two Cl- ions and the mechanisms of their retention both remain to be fully elucidated. However, intensive studies performed recently have advanced our understanding of the functions of these Cl- ions, and PSII structures from various species have been reported, aiding the interpretation of previous findings regarding Cl- retention by extrinsic subunits. In this review, we summarize the findings to date on the roles of the two Cl- ions bound within the OEC. Additionally, together with a short summary of the functions of PSII membrane-extrinsic subunits, we discuss the mechanisms of Cl- retention by these extrinsic subunits.
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Affiliation(s)
- Ko Imaizumi
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan
| | - Kentaro Ifuku
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan.
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6
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Imaizumi K, Nishimura T, Nagao R, Saito K, Nakano T, Ishikita H, Noguchi T, Ifuku K. D139N mutation of PsbP enhances the oxygen-evolving activity of photosystem II through stabilized binding of a chloride ion. PNAS NEXUS 2022; 1:pgac136. [PMID: 36741451 PMCID: PMC9896922 DOI: 10.1093/pnasnexus/pgac136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Accepted: 07/19/2022] [Indexed: 02/07/2023]
Abstract
Photosystem II (PSII) is a multisubunit membrane protein complex that catalyzes light-driven oxidation of water to molecular oxygen. The chloride ion (Cl-) has long been known as an essential cofactor for oxygen evolution by PSII, and two Cl- ions (Cl-1 and Cl-2) have been found to specifically bind near the Mn4CaO5 cluster within the oxygen-evolving center (OEC). However, despite intensive studies on these Cl- ions, little is known about the function of Cl-2, the Cl- ion that is associated with the backbone nitrogens of D1-Asn338, D1-Phe339, and CP43-Glu354. In green plant PSII, the membrane extrinsic subunits-PsbP and PsbQ-are responsible for Cl- retention within the OEC. The Loop 4 region of PsbP, consisting of highly conserved residues Thr135-Gly142, is inserted close to Cl-2, but its importance has not been examined to date. Here, we investigated the importance of PsbP-Loop 4 using spinach PSII membranes reconstituted with spinach PsbP proteins harboring mutations in this region. Mutations in PsbP-Loop 4 had remarkable effects on the rate of oxygen evolution by PSII. Moreover, we found that a specific mutation, PsbP-D139N, significantly enhances the oxygen-evolving activity in the absence of PsbQ, but not significantly in its presence. The D139N mutation increased the Cl- retention ability of PsbP and induced a unique structural change in the OEC, as indicated by light-induced Fourier transform infrared (FTIR) difference spectroscopy and theoretical calculations. Our findings provide insight into the functional significance of Cl-2 in the water-oxidizing reaction of PSII.
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Affiliation(s)
- Ko Imaizumi
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Taishi Nishimura
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Ryo Nagao
- Division of Material Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan,Research Institute for Interdisciplinary Science, Okayama University, Okayama 700-8530, Japan
| | - Keisuke Saito
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan,Department of Applied Chemistry, The University of Tokyo, Tokyo 113-8654 , Japan
| | - Takeshi Nakano
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology, The University of Tokyo, Tokyo 153-8904, Japan,Department of Applied Chemistry, The University of Tokyo, Tokyo 113-8654 , Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan
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7
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Mandal M, Saito K, Ishikita H. Release of a Proton and Formation of a Low-Barrier Hydrogen Bond between Tyrosine D and D2-His189 in Photosystem II. ACS PHYSICAL CHEMISTRY AU 2022; 2:423-429. [PMID: 36855688 PMCID: PMC9955220 DOI: 10.1021/acsphyschemau.2c00019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In photosystem II (PSII), the second-lowest oxidation state (S1) of the oxygen-evolving Mn4CaO5 cluster is the most stable, as the radical form of the redox-active D2-Tyr160 is considered to be a candidate that accepts an electron from the lowest oxidation state (S0) in the dark. Using quantum mechanical/molecular mechanical calculations, we investigated the redox potential (E m) of TyrD and its H-bond partner, D2-His189. The potential energy profile indicates that the release of a proton from the TyrD...D2-His189 pair leads to the formation of a low-barrier H-bond. The E m depends on the H+ position along the low-barrier H-bond, e.g., 680 mV when the H+ is at the D2-His189 moiety and 800 mV when the H+ is at the TyrD moiety, which can explain why TyrD mediates both the S0 to S1 oxidation and the S2 to S1 reduction.
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Affiliation(s)
- Manoj Mandal
- Department
of Chemical, Biological & Macro-Molecular Sciences, S. N. Bose National Centre for Basic Sciences, Kolkata 700106, West Bengal, India
| | - Keisuke Saito
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan,Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi Ishikita
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan,Department
of Applied Chemistry, The University of
Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan,. Tel: +81-3-5452-5056. Fax: +81-3-5452-5083
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8
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Kitanosono T, Hashidoko A, Yamashita Y, Kobayashi S. 2-Methoxyethyl Nitrite as a Reagent for Chemoselective On-Water Nitration. Chem Asian J 2022; 17:e202200457. [PMID: 35612572 DOI: 10.1002/asia.202200457] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/23/2022] [Indexed: 11/11/2022]
Abstract
An on-water approach has been developed that allows a nitration of tyrosines and phenols under mild conditions. We envisioned that the assembly of tyrosine/tyrosyl radical couples with interfacial water molecules would realize a biomimetic stacking hydrogen atom transfer (HAT) transition state to facilitate the electron-transfer process. The optimal organic nitrite, 2-methoxyethyl nitrite, resulted in rapid coupling of the tyrosyl radicals with •NO 2 at the oil-water interface to afford the nitrated phenols. Many characteristics found in our on-water strategy are distinct from other complementary systems that include radical nitration. These enticing roles of water in the reaction process introduce new avenues to explore in the design of synthetic organic chemistry systems.
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Affiliation(s)
- Taku Kitanosono
- The University of Tokyo: Tokyo Daigaku, Department of Chemistry, JAPAN
| | - Airu Hashidoko
- The University of Tokyo: Tokyo Daigaku, Department of Chemistry, JAPAN
| | | | - Shu Kobayashi
- The University of Tokyo, Department of Chemistry, School of Science, 7-3-1 Hongo, Bunkyo-ku, 113-0033, Tokyo, JAPAN
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9
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Mamedov MD, Milanovsky GE, Malferrari M, Vitukhnovskaya LA, Francia F, Semenov AY, Venturoli G. Trehalose matrix effects on electron transfer in Mn-depleted protein-pigment complexes of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2021; 1862:148413. [PMID: 33716033 DOI: 10.1016/j.bbabio.2021.148413] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/15/2021] [Accepted: 03/07/2021] [Indexed: 11/18/2022]
Abstract
The kinetics of flash-induced re-reduction of the Photosystem II (PS II) primary electron donor P680 was studied in solution and in trehalose glassy matrices at different relative humidity. In solution, and in the re-dissolved glass, kinetics were dominated by two fast components with lifetimes in the range of 2-7 μs, which accounted for >85% of the decay. These components were ascribed to the direct electron transfer from the redox-active tyrosine YZ to P680+. The minor slower components were due to charge recombination between the primary plastoquinone acceptor QA- and P680+. Incorporation of the PS II complex into the trehalose glassy matrix and its successive dehydration caused a progressive increase in the lifetime of all kinetic phases, accompanied by an increase of the amplitudes of the slower phases at the expense of the faster phases. At 63% relative humidity the fast components contribution dropped to ~50%. A further dehydration of the trehalose glass did not change the lifetimes and contribution of the kinetic components. This effect was ascribed to the decrease of conformational mobility of the protein domain between YZ and P680, which resulted in the inhibition of YZ → P680+ electron transfer in about half of the PS II population, wherein the recombination between QA- and P680+ occurred. The data indicate that PS II binds a larger number of water molecules as compared to PS I complexes. We conclude that our data disprove the "water replacement" hypothesis of trehalose matrix biopreservation.
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Affiliation(s)
- Mahir D Mamedov
- A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Leninskye gory, 1, b.40, Russia
| | - Georgy E Milanovsky
- A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Leninskye gory, 1, b.40, Russia
| | - Marco Malferrari
- Laboratory of Biochemistry and Molecular Biophysics, Department of Pharmacy and Biotechnology, FaBiT, University of Bologna, Bologna, Via Irnerio, 42, Italy
| | - Liya A Vitukhnovskaya
- A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Leninskye gory, 1, b.40, Russia; N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119991, Kosygina Street, 4, b.1, Russia
| | - Francesco Francia
- Laboratory of Biochemistry and Molecular Biophysics, Department of Pharmacy and Biotechnology, FaBiT, University of Bologna, Bologna, Via Irnerio, 42, Italy
| | - Alexey Yu Semenov
- A.N. Belozersky Institute of Physical-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Leninskye gory, 1, b.40, Russia; N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119991, Kosygina Street, 4, b.1, Russia.
| | - Giovanni Venturoli
- Laboratory of Biochemistry and Molecular Biophysics, Department of Pharmacy and Biotechnology, FaBiT, University of Bologna, Bologna, Via Irnerio, 42, Italy; Consorzio Nazionale Interuniversitario per le Scienze Fisiche della Materia, CNISM, c/o Department of Physics and Astronomy "Augusto Righi", DIFA, University of Bologna, Bologna, Via Irnerio, 46, Italy.
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10
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Kodru S, Sass L, Patil P, Szabó M, Vass I. Identification of the AG afterglow thermoluminescence band in the cyanobacterium Synechocystis PCC 6803. PHYSIOLOGIA PLANTARUM 2021; 171:291-300. [PMID: 33314124 DOI: 10.1111/ppl.13317] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/01/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
The so-called afterglow, AG, thermoluminescence (TL) band is a useful indicator of the presence of cyclic electron flow (CEF), which is mediated by the NADH dehydrogenase-like (NDH) complex in higher plants. Although NDH-dependent CEF occurs also in cyanobacteria, the AG band has previously not been found in these organisms. In the present study, we tested various experimental conditions and could identify a TL component with ca. +40°C peak temperature in Synechocystis PCC 6803 cells, which were illuminated by far-red (FR) light at around -10°C. The +40°C band could be observed when WT cells were grown under ambient air level CO2 , but was absent in the M55 mutant, which is deficient in the NDH-1 complex. These experimental observations match the characteristics of the AG band of higher plants. Therefore, we conclude that the newly identified +40°C TL component in Synechocystis PCC 6803 is the cyanobacterial counterpart of the plant AG band and originates from NDH-1-mediated CEF. The cyanobacterial AG band was most efficiently induced when FR illumination was applied at -10°C and its contribution to the total TL intensity declined when cells were illuminated above and below this temperature. Based on this phenomenon we also conclude that CEF is blocked by low temperatures at two different sites in Synechocystis PCC 6803: (1) Below -10°C at the level of NDH-1 and (2) below -30°C at the donor or acceptor side of Photosystem I.
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Affiliation(s)
- Sandeesha Kodru
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
- Doctoral School of Biology, University of Szeged, Szeged, Hungary
| | - László Sass
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Priyanka Patil
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Milán Szabó
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Szeged, Hungary
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11
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Ghosh I, Banerjee G, Reiss K, Kim CJ, Debus RJ, Batista VS, Brudvig GW. D1-S169A substitution of photosystem II reveals a novel S 2-state structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148301. [PMID: 32860756 DOI: 10.1016/j.bbabio.2020.148301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 08/18/2020] [Accepted: 08/22/2020] [Indexed: 10/23/2022]
Abstract
In photosystem II (PSII), photosynthetic water oxidation occurs at the O2-evolving complex (OEC), a tetramanganese-calcium cluster that cycles through light-induced redox intermediates (S0-S4) to produce oxygen from two substrate water molecules. The OEC is surrounded by a hydrogen-bonded network of amino-acid residues that plays a crucial role in proton transfer and substrate water delivery. Previously, we found that D1-S169 was crucial for water oxidation and its mutation to alanine perturbed the hydrogen-bonding network. In this study, we demonstrate that the activation energy for the S2 to S1 transition of D1-S169A PSII is higher than wild-type PSII with a ~1.7-2.7× slower rate of charge recombination with QA- relative to wild-type PSII. Arrhenius analysis of the decay kinetics shows an Ea of 5.87 ± 1.15 kcal mol-1 for decay back to the S1 state, compared to 0.80 ± 0.13 kcal mol-1 for the wild-type S2 state. In addition, we find that ammonia does not affect the S2-state EPR signal, indicating that ammonia does not bind to the Mn cluster in D1-S169A PSII. Finally, a QM/MM analysis indicates that an additional water molecule binds to the Mn4 ion in place of an oxo ligand O5 in the S2 state of D1-S169A PSII. The altered S2 state of D1-S169A PSII provides insight into the S2➔S3 state transition.
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Affiliation(s)
- Ipsita Ghosh
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Gourab Banerjee
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Krystle Reiss
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Christopher J Kim
- Department of Biochemistry, University of California, Riverside, CA 92521, USA
| | - Richard J Debus
- Department of Biochemistry, University of California, Riverside, CA 92521, USA.
| | - Victor S Batista
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Gary W Brudvig
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA.
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12
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Determining the Electronic Structure of Paramagnetic Intermediates in membrane proteins: A high-resolution 2D 1H hyperfine sublevel correlation study of the redox-active tyrosines of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183422. [DOI: 10.1016/j.bbamem.2020.183422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/19/2020] [Accepted: 07/15/2020] [Indexed: 01/26/2023]
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13
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Kuroda H, Kawashima K, Ueda K, Ikeda T, Saito K, Ninomiya R, Hida C, Takahashi Y, Ishikita H. Proton transfer pathway from the oxygen-evolving complex in photosystem II substantiated by extensive mutagenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1862:148329. [PMID: 33069681 DOI: 10.1016/j.bbabio.2020.148329] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 12/11/2022]
Abstract
We report a structure-based biological approach to identify the proton-transfer pathway in photosystem II. First, molecular dynamics (MD) simulations were conducted to analyze the H-bond network that may serve as a Grotthuss-like proton conduit. MD simulations show that D1-Asp61, the H-bond acceptor of H2O at the Mn4CaO5 cluster (W1), forms an H-bond via one water molecule with D1-Glu65 but not with D2-Glu312. Then, D1-Asp61, D1-Glu65, D2-Glu312, and the adjacent residues, D1-Arg334, D2-Glu302, and D2-Glu323, were thoroughly mutated to the other 19 residues, i.e., 114 Chlamydomonas chloroplast mutant cells were generated. Mutation of D1-Asp61 was most crucial. Only the D61E and D61C cells grew photoautotrophically and exhibit O2-evolving activity. Mutations of D2-Glu312 were less crucial to photosynthetic growth than mutations of D1-Glu65. Quantum mechanical/molecular mechanical calculations indicated that in the PSII crystal structure, the proton is predominantly localized at D1-Glu65 along the H-bond with D2-Glu312, i.e., pKa(D1-Glu65) > pKa(D2-Glu312). The potential-energy profile shows that the release of the proton from D1-Glu65 leads to the formation of the two short H-bonds between D1-Asp61 and D1-Glu65, which facilitates downhill proton transfer along the Grotthuss-like proton conduit in the S2 to S3 transition. It seems possible that D1-Glu65 is involved in the dominant pathway that proceeds from W1 via D1-Asp61 toward the thylakoid lumen, whereas D2-Glu312 and D1-Arg334 may be involved in alternative pathways in some mutants.
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Affiliation(s)
- Hiroshi Kuroda
- Research Institute for Interdisciplinary Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Keisuke Kawashima
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan
| | - Kazuyo Ueda
- Graduate School of Natural Science and Technology, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Takuya Ikeda
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan; Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Ryo Ninomiya
- Department of Biology, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Chisato Hida
- Department of Biology, Faculty of Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Yuichiro Takahashi
- Research Institute for Interdisciplinary Science, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.
| | - Hiroshi Ishikita
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-Ku, Tokyo 113-8654, Japan; Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan.
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14
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Méndez-Hernández DD, Baldansuren A, Kalendra V, Charles P, Mark B, Marshall W, Molnar B, Moore TA, Lakshmi KV, Moore AL. HYSCORE and DFT Studies of Proton-Coupled Electron Transfer in a Bioinspired Artificial Photosynthetic Reaction Center. iScience 2020; 23:101366. [PMID: 32738611 PMCID: PMC7394912 DOI: 10.1016/j.isci.2020.101366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 06/22/2020] [Accepted: 07/10/2020] [Indexed: 11/24/2022] Open
Abstract
The photosynthetic water-oxidation reaction is catalyzed by the oxygen-evolving complex in photosystem II (PSII) that comprises the Mn4CaO5 cluster, with participation of the redox-active tyrosine residue (YZ) and a hydrogen-bonded network of amino acids and water molecules. It has been proposed that the strong hydrogen bond between YZ and D1-His190 likely renders YZ kinetically and thermodynamically competent leading to highly efficient water oxidation. However, a detailed understanding of the proton-coupled electron transfer (PCET) at YZ remains elusive owing to the transient nature of its intermediate states involving YZ⋅. Herein, we employ a combination of high-resolution two-dimensional 14N hyperfine sublevel correlation spectroscopy and density functional theory methods to investigate a bioinspired artificial photosynthetic reaction center that mimics the PCET process involving the YZ residue of PSII. Our results underscore the importance of proximal water molecules and charge delocalization on the electronic structure of the artificial reaction center. Structural factors are critical in the design of artificial photosynthetic systems Correlation between hyperfine couplings of the N atoms and electron spin density Spin density distribution affected by charge delocalization and explicit waters Spin density modulation by electronic coupling as observed with P680 and YZ in PSII
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Affiliation(s)
| | - Amgalanbaatar Baldansuren
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Vidmantas Kalendra
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Philip Charles
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Brian Mark
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - William Marshall
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Brian Molnar
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
| | - Thomas A Moore
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - K V Lakshmi
- Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
| | - Ana L Moore
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
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15
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Acquirement of water-splitting ability and alteration of the charge-separation mechanism in photosynthetic reaction centers. Proc Natl Acad Sci U S A 2020; 117:16373-16382. [PMID: 32601233 PMCID: PMC7368266 DOI: 10.1073/pnas.2000895117] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
In photosynthetic reaction centers from purple bacteria (PbRC) and the water-oxidizing enzyme, photosystem II (PSII), charge separation occurs along one of the two symmetrical electron-transfer branches. Here we report the microscopic origin of the unidirectional charge separation, fully considering electron-hole interaction, electronic coupling of the pigments, and electrostatic interaction with the polarizable entire protein environments. The electronic coupling between the pair of bacteriochlorophylls is large in PbRC, forming a delocalized excited state with the lowest excitation energy (i.e., the special pair). The charge-separated state in the active branch is stabilized by uncharged polar residues in the transmembrane region and charged residues on the cytochrome c 2 binding surface. In contrast, the accessory chlorophyll in the D1 protein (ChlD1) has the lowest excitation energy in PSII. The charge-separated state involves ChlD1 •+ and is stabilized predominantly by charged residues near the Mn4CaO5 cluster and the proceeding proton-transfer pathway. It seems likely that the acquirement of water-splitting ability makes ChlD1 the initial electron donor in PSII.
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16
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Boussac A, Sellés J, Sugiura M. What can we still learn from the electrochromic band-shifts in Photosystem II? BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2020; 1861:148176. [PMID: 32061653 DOI: 10.1016/j.bbabio.2020.148176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 01/29/2020] [Accepted: 02/10/2020] [Indexed: 11/17/2022]
Abstract
Electrochromic band-shifts have been investigated in Photosystem II (PSII) from Thermosynechoccocus elongatus. Firstly, by using Mn-depleted PsbA1-PSII and PsbA3-PSII in which the QX absorption of PheD1 differs, a band-shift in the QX region of PheD2 centered at ~ 544 nm has been identified upon the oxidation, at pH 8.6, of TyrD. In contrast, a band-shift due to the formation of either QA•- or TyrZ• is observed in PsbA3-PSII at ~ 546 nm, as expected with E130 H-bonded to PheD1 and at ~ 544 nm as expected with Q130 H-bonded to PheD1. Secondly, electrochromic band-shifts in the Chla Soret region have been measured in O2-evolving PSII in PsbA3-PSII, in the PsbA3/H198Q mutant in which the Soret band of PD1 is blue shifted and in the PsbA3/T179H mutant. Upon TyrZ•QA•- formation the Soret band of PD1 is red shifted and the Soret band of ChlD1 is blue shifted. In contrast, only PD1 undergoes a detectable S-state dependent electrochromism. Thirdly, the time resolved S-state dependent electrochromism attributed to PD1 is biphasic for all the S-state transitions except for S1 to S2, and shows that: i) the proton release in S0 to S1 occurs after the electron transfer and ii) the proton release and the electron transfer kinetics in S2 to S3, in T. elongatus, are significantly faster than often considered. The nature of S2TyrZ• is discussed in view of the models in the literature involving intermediate states in the S2 to S3 transition.
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Affiliation(s)
- Alain Boussac
- I(2)BC, CNRS UMR 9198, CEA Saclay, 91191 Gif-sur-Yvette, France.
| | - Julien Sellés
- Institut de Biologie Physico-Chimique, CNRS UMR 7141 and Sorbonne Université, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Miwa Sugiura
- Proteo-Science Research Center and Graduate School of Science and Technology, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
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17
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Mandal M, Kawashima K, Saito K, Ishikita H. Redox Potential of the Oxygen-Evolving Complex in the Electron Transfer Cascade of Photosystem II. J Phys Chem Lett 2020; 11:249-255. [PMID: 31729876 DOI: 10.1021/acs.jpclett.9b02831] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In photosystem II (PSII), water oxidation occurs in the Mn4CaO5 cluster with the release of electrons via the redox-active tyrosine (TyrZ) to the reaction-center chlorophylls (PD1/PD2). Using a quantum mechanical/molecular mechanical approach, we report the redox potentials (Em) of these cofactors in the PSII protein environment. The Em values suggest that the Mn4CaO5 cluster, TyrZ, and PD1/PD2 form a downhill electron transfer pathway. Em for the first oxidation step, Em(S0/S1), is uniquely low (730 mV) and is ∼100 mV lower than that for the second oxidation step, Em(S1/S2) (830 mV) only when the O4 site of the Mn4CaO5 cluster is protonated in S0. The O4-water chain, which directly forms a low-barrier H-bond with the Mn4CaO5 cluster and mediates proton-coupled electron transfer in the S0 to S1 transition, explains why the second lowest oxidation state, S1, is the most stable and S0 is converted to S1 even in the dark.
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Affiliation(s)
- Manoj Mandal
- Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba , Meguro-ku, Tokyo 153-8904 , Japan
| | - Keisuke Kawashima
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8654 , Japan
| | - Keisuke Saito
- Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba , Meguro-ku, Tokyo 153-8904 , Japan
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8654 , Japan
| | - Hiroshi Ishikita
- Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba , Meguro-ku, Tokyo 153-8904 , Japan
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-8654 , Japan
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18
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Nakamura S, Capone M, Narzi D, Guidoni L. Pivotal role of the redox-active tyrosine in driving the water splitting catalyzed by photosystem II. Phys Chem Chem Phys 2020; 22:273-285. [DOI: 10.1039/c9cp04605d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
TyrZ oxidation state triggers hydrogen bond modification in the water oxidation catalysis.
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Affiliation(s)
- Shin Nakamura
- Department of Biochemical Sciences “A. Rossi Fanelli”
- University of Rome “Sapienza”
- Rome
- Italy
| | - Matteo Capone
- Department of Information Engineering, Computational Science, and Mathematics
- Università dell’Aquila
- L’Aquila
- Italy
| | - Daniele Narzi
- Institute of Chemical Sciences and Engineering Ecole Polytechnique Federale de Lausanne Av. F.-A. Forel 2
- 1015 Lausanne
- Switzerland
| | - Leonardo Guidoni
- Department of Physical and Chemical Science
- Università dell’Aquila
- L’Aquila
- Italy
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19
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Sidabras JW, Duan J, Winkler M, Happe T, Hussein R, Zouni A, Suter D, Schnegg A, Lubitz W, Reijerse EJ. Extending electron paramagnetic resonance to nanoliter volume protein single crystals using a self-resonant microhelix. SCIENCE ADVANCES 2019; 5:eaay1394. [PMID: 31620561 PMCID: PMC6777973 DOI: 10.1126/sciadv.aay1394] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 09/06/2019] [Indexed: 05/26/2023]
Abstract
Electron paramagnetic resonance (EPR) spectroscopy on protein single crystals is the ultimate method for determining the electronic structure of paramagnetic intermediates at the active site of an enzyme and relating the magnetic tensor to a molecular structure. However, crystals of dimensions typical for protein crystallography (0.05 to 0.3mm) provide insufficient signal intensity. In this work, we present a microwave self-resonant microhelix for nanoliter samples that can be implemented in a commercial X-band (9.5 GHz) EPR spectrometer. The self-resonant microhelix provides a measured signal-to-noise improvement up to a factor of 28 with respect to commercial EPR resonators. This work opens up the possibility to use advanced EPR techniques for studying protein single crystals of dimensions typical for x-ray crystallography. The technique is demonstrated by EPR experiments on single crystal [FeFe]-hydrogenase (Clostridium pasteurianum; CpI) with dimensions of 0.3 mm by 0.1 mm by 0.1 mm, yielding a proposed g-tensor orientation of the Hox state.
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Affiliation(s)
- Jason W. Sidabras
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Jifu Duan
- AG Photobiotechnologie, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Martin Winkler
- AG Photobiotechnologie, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Thomas Happe
- AG Photobiotechnologie, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Rana Hussein
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
| | - Athina Zouni
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstraße 13, 10115 Berlin, Germany
| | - Dieter Suter
- Experimentelle Physik, Technische Universität Dortmund, Emil-Figge-Straße 50, 44221 Dortmund, Germany
| | - Alexander Schnegg
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Edward J. Reijerse
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
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20
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Banerjee G, Ghosh I, Kim CJ, Debus RJ, Brudvig GW. Bicarbonate rescues damaged proton-transfer pathway in photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:611-617. [DOI: 10.1016/j.bbabio.2019.06.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 06/18/2019] [Accepted: 06/21/2019] [Indexed: 01/04/2023]
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21
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Takahashi H, Suzuoka D, Sakuraba S, Morita A. Role of the Photosystem II as an Environment in the Oxidation Free Energy of the Mn Cluster from S 1 to S 2. J Phys Chem B 2019; 123:7081-7091. [PMID: 31282160 DOI: 10.1021/acs.jpcb.9b03831] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The manganese cluster (CaMn4O5) in the photosystem II (PSII) is the reaction center of the light-driven oxidation reaction, which generates the molecular oxygen. In this paper, we address the issue of the effect of the environment on the free energy associated with the oxidation of the Mn cluster in S1 state by conducting the large-scale quantum mechanical/molecular mechanical simulations, which involve the whole of the PSII monomer. It was found by the simulations at the level of the B3LYP functional that the environment surrounding the Mn cluster reduces the vertical oxidation free energy Δμvrt by 64.8 kcal/mol. A decomposition analysis of the free energy Δμvrt revealed that the system composed of peptide chains, ligands, lipids, and potassium ions contributes to lowering of Δμvrt by -98.0 kcal/mol, whereas the solvent water makes an opposite contribution of 38.9 kcal/mol. Reduction of the vertical oxidation free energy directly leads to the lowering of the activation free energy ΔGac for the electron transfer reaction from the Mn cluster in S1 state to the neighboring Tyrz+. Consequently, the electron transfer rate was found to be enhanced by a factor of 1012 by virtue of the influence of the environment.
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Affiliation(s)
- Hideaki Takahashi
- Department of Chemistry, Graduate School of Science , Tohoku University , Sendai , Miyagi 980-8578 , Japan
| | - Daiki Suzuoka
- Department of Chemistry, Graduate School of Science , Tohoku University , Sendai , Miyagi 980-8578 , Japan
| | - Shun Sakuraba
- National Institutes for Quantum and Radiological Science and Technology , Kizugawa , Kyoto 619-0215 , Japan
| | - Akihiro Morita
- Department of Chemistry, Graduate School of Science , Tohoku University , Sendai , Miyagi 980-8578 , Japan.,Element Strategy Initiative for Catalysts and Batteries (ESICB) , Kyoto University , Kyoto 615-8520 , Japan
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22
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Time-Resolved Infrared and Visible Spectroscopy on Cryptochrome aCRY: Basis for Red Light Reception. Biophys J 2019; 117:490-499. [PMID: 31326107 DOI: 10.1016/j.bpj.2019.06.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 12/18/2022] Open
Abstract
Cryptochromes function as flavin-binding photoreceptors in bacteria, fungi, algae, land plants, and insects. The discovery of an animal-like cryptochrome in the green alga Chlamydomonas reinhardtii has expanded the spectral range of sensitivity of these receptors from ultraviolet A/blue light to almost the complete visible spectrum. The broadened light response has been explained by the presence of the flavin neutral radical as a chromophore in the dark. Concomitant with photoconversion of the flavin, an unusually long-lived tyrosyl radical with a red-shifted ultraviolet-visible spectrum is formed, which is essential for the function of the receptor. In this study, the microenvironment of this key residue, tyrosine 373, was scrutinized using time-resolved Fourier transform infrared spectroscopy on several variants of animal-like cryptochrome and density functional theory for band assignment. The reduced tyrosine takes on distinct hydrogen bond scenarios depending on the presence of the C-terminal extension and of a neighboring cysteine. Upon radical formation, all variants showed a signal at 1400 cm-1, which we assigned to the ν7'a marker band of the CO stretching mode. The exceptionally strong downshift of this band cannot be attributed to a loss of hydrogen bonding only. Time-resolved ultraviolet-visible spectroscopy on W322F, a mutant of the neighboring tryptophan residue, revealed a decrease of the tyrosyl radical lifetime by almost two orders of magnitude, along with a shift of the absorbance maximum from 416 to 398 nm. These findings strongly support the concept of a π-π stacking as an apolar interaction between Y373 and W322 to be responsible for the characteristics of the tyrosyl radical. This concept of radical stabilization has been unknown to cryptochromes so far but might be highly relevant for other homologs with a tetrad of tryptophans and tyrosines as electron donors.
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23
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Pham LV, Janna Olmos JD, Chernev P, Kargul J, Messinger J. Unequal misses during the flash-induced advancement of photosystem II: effects of the S state and acceptor side cycles. PHOTOSYNTHESIS RESEARCH 2019; 139:93-106. [PMID: 30191436 PMCID: PMC6373315 DOI: 10.1007/s11120-018-0574-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 08/03/2018] [Indexed: 05/17/2023]
Abstract
Photosynthetic water oxidation is catalyzed by the oxygen-evolving complex (OEC) in photosystem II (PSII). This process is energetically driven by light-induced charge separation in the reaction center of PSII, which leads to a stepwise accumulation of oxidizing equivalents in the OEC (Si states, i = 0-4) resulting in O2 evolution after each fourth flash, and to the reduction of plastoquinone to plastoquinol on the acceptor side of PSII. However, the Si-state advancement is not perfect, which according to the Kok model is described by miss-hits (misses). These may be caused by redox equilibria or kinetic limitations on the donor (OEC) or the acceptor side. In this study, we investigate the effects of individual S state transitions and of the quinone acceptor side on the miss parameter by analyzing the flash-induced oxygen evolution patterns and the S2, S3 and S0 state lifetimes in thylakoid samples of the extremophilic red alga Cyanidioschyzon merolae. The data are analyzed employing a global fit analysis and the results are compared to the data obtained previously for spinach thylakoids. These two organisms were selected, because the redox potential of QA/QA- in PSII is significantly less negative in C. merolae (Em = - 104 mV) than in spinach (Em = - 163 mV). This significant difference in redox potential was expected to allow the disentanglement of acceptor and donor side effects on the miss parameter. Our data indicate that, at slightly acidic and neutral pH values, the Em of QA-/QA plays only a minor role for the miss parameter. By contrast, the increased energy gap for the backward electron transfer from QA- to Pheo slows down the charge recombination reaction with the S3 and S2 states considerably. In addition, our data support the concept that the S2 → S3 transition is the least efficient step during the oxidation of water to molecular oxygen in the Kok cycle of PSII.
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Affiliation(s)
- Long Vo Pham
- Department of Chemistry - Ångström, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden
| | - Julian David Janna Olmos
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland
- Department of Molecular Biophysics, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387, Kraków, Poland
| | - Petko Chernev
- Department of Chemistry - Ångström, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden
| | - Joanna Kargul
- Solar Fuels Lab, Centre of New Technologies, University of Warsaw, Banacha 2C, 02-097, Warsaw, Poland.
| | - Johannes Messinger
- Department of Chemistry - Ångström, Uppsala University, Lägerhyddsvägen 1, 75120, Uppsala, Sweden.
- Department of Chemistry, Chemistry Biology Center (KBC), Umeå University, Linnaeus väg 6, 901 87, Umeå, Sweden.
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24
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Sirohiwal A, Neese F, Pantazis DA. Microsolvation of the Redox-Active Tyrosine-D in Photosystem II: Correlation of Energetics with EPR Spectroscopy and Oxidation-Induced Proton Transfer. J Am Chem Soc 2019; 141:3217-3231. [PMID: 30666866 PMCID: PMC6728127 DOI: 10.1021/jacs.8b13123] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photosystem II (PSII) of oxygenic photosynthesis captures sunlight to drive the catalytic oxidation of water and the reduction of plastoquinone. Among the several redox-active cofactors that participate in intricate electron transfer pathways there are two tyrosine residues, YZ and YD. They are situated in symmetry-related electron transfer branches but have different environments and play distinct roles. YZ is the immediate oxidant of the oxygen-evolving Mn4CaO5 cluster, whereas YD serves regulatory and protective functions. The protonation states and hydrogen-bond network in the environment of YD remain debated, while the role of microsolvation in stabilizing different redox states of YD and facilitating oxidation or mediating deprotonation, as well the fate of the phenolic proton, is unclear. Here we present detailed structural models of YD and its environment using large-scale quantum mechanical models and all-atom molecular dynamics of a complete PSII monomer. The energetics of water distribution within a hydrophobic cavity adjacent to YD are shown to correlate directly with electron paramagnetic resonance (EPR) parameters such as the tyrosyl g-tensor, allowing us to map the correspondence between specific structural models and available experimental observations. EPR spectra obtained under different conditions are explained with respect to the mode of interaction of the proximal water with the tyrosyl radical and the position of the phenolic proton within the cavity. Our results revise previous models of the energetics and build a detailed view of the role of confined water in the oxidation and deprotonation of YD. Finally, the model of microsolvation developed in the present work rationalizes in a straightforward way the biphasic oxidation kinetics of YD, offering new structural insights regarding the function of the radical in biological photosynthesis.
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Affiliation(s)
- Abhishek Sirohiwal
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , 45470 Mülheim an der Ruhr , Germany
- Fakultät für Chemie und Biochemie , Ruhr-Universität Bochum , 44780 Bochum , Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , 45470 Mülheim an der Ruhr , Germany
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung , Kaiser-Wilhelm-Platz 1 , 45470 Mülheim an der Ruhr , Germany
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25
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Chai J, Zheng Z, Pan H, Zhang S, Lakshmi KV, Sun YY. Significance of hydrogen bonding networks in the proton-coupled electron transfer reactions of photosystem II from a quantum-mechanics perspective. Phys Chem Chem Phys 2019; 21:8721-8728. [DOI: 10.1039/c9cp00868c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
All quantum-mechanical calculations provide insights into the effect of the hydrogen bonding network on the proton-coupled electron transfer at YZ and YD in photosystem II.
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Affiliation(s)
- Jun Chai
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 201899
- China
| | - Zhaoyang Zheng
- National Key Laboratory of Shock Wave and Detonation Physics
- Institute of Fluid Physics
- China Academy of Engineering Physics
- Mianyang 621900
- China
| | - Hui Pan
- Joint Key Laboratory of the Ministry of Education
- Institute of Applied Physics and Materials Engineering
- University of Macau
- Taipa
- China
| | - Shengbai Zhang
- Department of Physics
- Applied Physics, and Astronomy
- Rensselaer Polytechnic Institute
- Troy
- USA
| | - K. V. Lakshmi
- Department of Chemistry and Chemical Biology and The Baruch ’60 Center for Biochemical Solar Energy Research
- Rensselaer Polytechnic Institute
- Troy
- USA
| | - Yi-Yang Sun
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure
- Shanghai Institute of Ceramics
- Chinese Academy of Sciences
- Shanghai 201899
- China
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26
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Morris JN, Kovács S, Vass I, Summerfield TC, Eaton-Rye JJ. Environmental pH and a Glu364 to Gln mutation in the chlorophyll-binding CP47 protein affect redox-active TyrD and charge recombination in Photosystem II. FEBS Lett 2018; 593:163-174. [PMID: 30485416 DOI: 10.1002/1873-3468.13307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 11/19/2018] [Accepted: 11/19/2018] [Indexed: 12/16/2022]
Abstract
In Photosystem II, loop E of the chlorophyll-binding CP47 protein is located near a redox-active tyrosine, YD , forming a symmetrical analog to loop E in CP43, which provides a ligand to the oxygen-evolving complex (OEC). A Glu364 to Gln substitution in CP47, near YD , does not affect growth in the cyanobacterium Synechocystis sp. PCC 6803; however, deletion of the extrinsic protein PsbV in this mutant leads to a strain displaying a pH-sensitive phenotype. Using thermoluminescence, chlorophyll fluorescence, and flash-induced oxygen evolution analyses, we demonstrate that Glu364 influences the stability of YD and the redox state of the OEC, and highlight the effects of external pH on photosynthetic electron transfer in intact cyanobacterial cells.
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Affiliation(s)
- Jaz N Morris
- Department of Botany, University of Otago, Dunedin, New Zealand.,Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Sándor Kovács
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Imre Vass
- Institute of Plant Biology, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
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27
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Shamsipur M, Pashabadi A. Latest advances in PSII features and mechanism of water oxidation. Coord Chem Rev 2018. [DOI: 10.1016/j.ccr.2018.07.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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28
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Takahashi M, Morikawa H. A novel role for PsbO1 in photosynthetic electron transport as suggested by its light-triggered selective nitration in Arabidopsis thaliana. PLANT SIGNALING & BEHAVIOR 2018; 13:e1513298. [PMID: 30230951 PMCID: PMC6259825 DOI: 10.1080/15592324.2018.1513298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 08/07/2018] [Accepted: 08/10/2018] [Indexed: 06/08/2023]
Abstract
Exposure of Arabidopsis leaves to nitrogen dioxide (NO2) results in the selective nitration of specific proteins, such as PsbO1. The 9th tyrosine residue (9Tyr) of PsbO1 has been identified as the nitration site. This nitration is triggered by light and inhibited by photosynthetic electron transport inhibitors. During protein nitration, tyrosyl and NO2 radicals are formed concurrently and combine rapidly to form 3-nitrotyrosine. A selective oxidation mechanism for 9Tyr of PsbO1 is required. We postulated that, similar to 161Tyr of D1, 9Tyr of PsbO1 is selectively photo-oxidized by photosynthetic electron transport in response to illumination to a tyrosyl radical. In corroboration, after reappraising our oxygen evolution analysis, the nitration of PsbO1 proved responsible for decreased oxygen evolution from the thylakoid membranes. NO2 is reportedly taken into cells as nitrous acid, which dissociates to form NO2-. NO2- may be oxidized into NO2 by the oxygen-evolving complex. Light may synchronize this reaction with tyrosyl radical formation. These findings suggest a novel role for PsbO1 in photosynthetic electron transport.
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Affiliation(s)
- Misa Takahashi
- Department of Mathematical and Life Sciences, Hiroshima University, Higashi-Hiroshima, Japan
| | - Hiromichi Morikawa
- Department of Mathematical and Life Sciences, Hiroshima University, Higashi-Hiroshima, Japan
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29
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Ahmadova N, Mamedov F. Formation of tyrosine radicals in photosystem II under far-red illumination. PHOTOSYNTHESIS RESEARCH 2018; 136:93-106. [PMID: 28924898 PMCID: PMC5851703 DOI: 10.1007/s11120-017-0442-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 09/05/2017] [Indexed: 05/27/2023]
Abstract
Photosystem II (PS II) contains two redox-active tyrosine residues on the donor side at symmetrical positions to the primary donor, P680. TyrZ, part of the water-oxidizing complex, is a preferential fast electron donor while TyrD is a slow auxiliary donor to P680+. We used PS II membranes from spinach which were depleted of the water oxidation complex (Mn-depleted PS II) to study electron donation from both tyrosines by time-resolved EPR spectroscopy under visible and far-red continuous light and laser flash illumination. Our results show that under both illumination regimes, oxidation of TyrD occurs via equilibrium with TyrZ• at pH 4.7 and 6.3. At pH 8.5 direct TyrD oxidation by P680+ occurs in the majority of the PS II centers. Under continuous far-red light illumination these reactions were less effective but still possible. Different photochemical steps were considered to explain the far-red light-induced electron donation from tyrosines and localization of the primary electron hole (P680+) on the ChlD1 in Mn-depleted PS II after the far-red light-induced charge separation at room temperature is suggested.
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Affiliation(s)
- Nigar Ahmadova
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 751 20, Uppsala, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department of Chemistry - Ångström Laboratory, Uppsala University, Box 523, 751 20, Uppsala, Sweden.
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30
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Kawashima K, Takaoka T, Kimura H, Saito K, Ishikita H. O 2 evolution and recovery of the water-oxidizing enzyme. Nat Commun 2018; 9:1247. [PMID: 29593210 PMCID: PMC5871790 DOI: 10.1038/s41467-018-03545-w] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 02/20/2018] [Indexed: 01/14/2023] Open
Abstract
In photosystem II, light-induced water oxidation occurs at the Mn4CaO5 cluster. Here we demonstrate proton releases, dioxygen formation, and substrate water incorporation in response to Mn4CaO5 oxidation in the protein environment, using a quantum mechanical/molecular mechanical approach and molecular dynamics simulations. In S2, H2O at the W1 site forms a low-barrier H-bond with D1-Asp61. In the S2-to-S3 transition, oxidation of OW1H– to OW1•–, concerted proton transfer from OW1H– to D1-Asp61, and binding of a water molecule Wn-W1 at OW1•– are observed. In S4, Wn-W1 facilitates oxo-oxyl radical coupling between OW1•– and corner μ-oxo O4. Deprotonation via D1-Asp61 leads to formation of OW1=O4. As OW1=O4 moves away from Mn, H2O at W539 is incorporated into the vacant O4 site of the O2-evolved Mn4CaO4 cluster, forming a μ-oxo bridge (Mn3–OW539–Mn4) in an exergonic process. Simultaneously, Wn-W1 is incorporated as W1, recovering the Mn4CaO5 cluster. Water splitting during photosynthesis results in the combination of two oxygen atoms to form O2. Here, based on computational simulations, the authors develop a possible mechanism for this reaction, which is different from the mechanisms previous studies have suggested.
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Affiliation(s)
- Keisuke Kawashima
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan
| | - Tomohiro Takaoka
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan
| | - Hiroki Kimura
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan
| | - Keisuke Saito
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan.,Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan
| | - Hiroshi Ishikita
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8654, Japan. .,Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8904, Japan.
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31
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Kawashima K, Ishikita H. Energetic insights into two electron transfer pathways in light-driven energy-converting enzymes. Chem Sci 2018; 9:4083-4092. [PMID: 29780537 PMCID: PMC5944228 DOI: 10.1039/c8sc00424b] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 03/28/2018] [Indexed: 11/21/2022] Open
Abstract
We report Em values of (bacterio-)chlorophylls for one-electron reduction in both electron-transfer branches of PbRC, PSI, and PSII.
We report redox potentials (Em) for one-electron reduction for all chlorophylls in the two electron-transfer branches of water-oxidizing enzyme photosystem II (PSII), photosystem I (PSI), and purple bacterial photosynthetic reaction centers (PbRC). In PSI, Em values for the accessory chlorophylls were similar in both electron-transfer branches. In PbRC, the corresponding Em value was 170 mV less negative in the active L-branch (BL) than in the inactive M-branch (BM), favoring BL˙– formation. This contrasted with the corresponding chlorophylls, ChlD1 and ChlD2, in PSII, where Em(ChlD1) was 120 mV more negative than Em(ChlD2), implying that to rationalize electron transfer in the D1-branch, ChlD1 would need to serve as the primary electron donor. Residues that contributed to Em(ChlD1) < Em(ChlD2) simultaneously played a key role in (i) releasing protons from the substrate water molecules and (ii) contributing to the larger cationic population on the chlorophyll closest to the Mn4CaO5 cluster (PD1), favoring electron transfer from water molecules. These features seem to be the nature of PSII, which needs to possess the proton-exit pathway to use a protonated electron source—water molecules.
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Affiliation(s)
- Keisuke Kawashima
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku , Tokyo 113-8654 , Japan .
| | - Hiroshi Ishikita
- Department of Applied Chemistry , The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku , Tokyo 113-8654 , Japan . .,Research Center for Advanced Science and Technology , The University of Tokyo , 4-6-1 Komaba, Meguro-ku , Tokyo 153-8904 , Japan . ; Tel: +81-3-5452-5056
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32
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Beal NJ, Corry TA, O'Malley PJ. A Comparison of Experimental and Broken Symmetry Density Functional Theory (BS-DFT) Calculated Electron Paramagnetic Resonance (EPR) Parameters for Intermediates Involved in the S 2 to S 3 State Transition of Nature's Oxygen Evolving Complex. J Phys Chem B 2018; 122:1394-1407. [PMID: 29300480 DOI: 10.1021/acs.jpcb.7b10843] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A broken symmetry density functional theory (BS-DFT) magnetic analysis of the S2, S2YZ•, and S3 states of Nature's oxygen evolving complex is performed for both the native Ca and Sr substituted forms. Good agreement with experiment is observed between the tyrosyl calculated g-tensor and 1H hyperfine couplings for the native Ca form. Changes in the hydrogen bonding environment of the tyrosyl radical in S2YZ• caused by Sr substitution lead to notable changes in the calculated g-tensor of the tyrosyl radical. Comparison of calculated and experimental 55Mn hyperfine couplings for the S3 state presently favors an open cubane form of the complex with an additional OH ligand coordinating to MnD. In Ca models, this additional ligation can arise by closed-cubane form deprotonation of the Ca ligand W3 in the S2YZ• state accompanied by spontaneous movement to the vacant Mn coordination site or by addition of an external OH group. For the Sr form, no spontaneous movement of W3 to the vacant Mn coordination site is observed in contrast to the native Ca form, a difference which may lead to the reduced catalytic activity of the Sr substituted form. BS-DFT studies on peroxo models of S3 as indicated by a recent X-ray free electron laser (XFEL) crystallography study give rise to a structural model compatible with experimental data and an S = 3 ground state compatible with EPR studies.
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Affiliation(s)
- Nathan J Beal
- School of Chemistry, The University of Manchester , Manchester M13 9PL, U.K
| | - Thomas A Corry
- School of Chemistry, The University of Manchester , Manchester M13 9PL, U.K
| | - Patrick J O'Malley
- School of Chemistry, The University of Manchester , Manchester M13 9PL, U.K
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33
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Lohmiller T, Krewald V, Sedoud A, Rutherford AW, Neese F, Lubitz W, Pantazis DA, Cox N. The First State in the Catalytic Cycle of the Water-Oxidizing Enzyme: Identification of a Water-Derived μ-Hydroxo Bridge. J Am Chem Soc 2017; 139:14412-14424. [DOI: 10.1021/jacs.7b05263] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Thomas Lohmiller
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Vera Krewald
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Arezki Sedoud
- Department
of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
- iBiTec-S, URA
CNRS 2096, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - A. William Rutherford
- Department
of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
- iBiTec-S, URA
CNRS 2096, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Frank Neese
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Lubitz
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Dimitrios A. Pantazis
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Nicholas Cox
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
- Research
School of Chemistry, Australian National University, Canberra, Australian Capital Territory 2601, Australia
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34
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Sakashita N, Watanabe HC, Ikeda T, Saito K, Ishikita H. Origins of Water Molecules in the Photosystem II Crystal Structure. Biochemistry 2017; 56:3049-3057. [DOI: 10.1021/acs.biochem.7b00220] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Naoki Sakashita
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Hiroshi C. Watanabe
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Takuya Ikeda
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
| | - Keisuke Saito
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
| | - Hiroshi Ishikita
- Department
of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8654, Japan
- Research
Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8904, Japan
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35
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Ahmadova N, Ho FM, Styring S, Mamedov F. Tyrozine D oxidation and redox equilibrium in photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:407-417. [DOI: 10.1016/j.bbabio.2017.02.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 02/17/2017] [Accepted: 02/20/2017] [Indexed: 10/20/2022]
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36
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Nagao R, Yamaguchi M, Nakamura S, Ueoka-Nakanishi H, Noguchi T. Genetically introduced hydrogen bond interactions reveal an asymmetric charge distribution on the radical cation of the special-pair chlorophyll P680. J Biol Chem 2017; 292:7474-7486. [PMID: 28302724 DOI: 10.1074/jbc.m117.781062] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 03/08/2017] [Indexed: 11/06/2022] Open
Abstract
The special-pair chlorophyll (Chl) P680 in photosystem II has an extremely high redox potential (Em ) to enable water oxidation in photosynthesis. Significant positive-charge localization on one of the Chl constituents, PD1 or PD2, in P680+ has been proposed to contribute to this high Em To identify the Chl molecule on which the charge is mainly localized, we genetically introduced a hydrogen bond to the 131-keto C=O group of PD1 and PD2 by changing the nearby D1-Val-157 and D2-Val-156 residues to His, respectively. Successful hydrogen bond formation at PD1 and PD2 in the obtained D1-V157H and D2-V156H mutants, respectively, was monitored by detecting 131-keto C=O vibrations in Fourier transfer infrared (FTIR) difference spectra upon oxidation of P680 and the symmetrically located redox-active tyrosines YZ and YD, and they were simulated by quantum-chemical calculations. Analysis of the P680+/P680 FTIR difference spectra of D1-V157H and D2-V156H showed that upon P680+ formation, the 131-keto C=O frequency upshifts by a much larger extent in PD1 (23 cm-1) than in PD2 (<9 cm-1). In addition, thermoluminescence measurements revealed that the D1-V157H mutation increased the Em of P680 to a larger extent than did the D2-V156H mutation. These results, together with the previous results for the mutants of the His ligands of PD1 and PD2, lead to a definite conclusion that a charge is mainly localized to PD1 in P680<sup/>.
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Affiliation(s)
- Ryo Nagao
- From the Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Motoki Yamaguchi
- From the Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Shin Nakamura
- From the Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Hanayo Ueoka-Nakanishi
- From the Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Takumi Noguchi
- From the Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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37
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Light-induced structural changes and the site of O=O bond formation in PSII caught by XFEL. Nature 2017; 543:131-135. [PMID: 28219079 DOI: 10.1038/nature21400] [Citation(s) in RCA: 425] [Impact Index Per Article: 60.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 01/17/2017] [Indexed: 12/24/2022]
Abstract
Photosystem II (PSII) is a huge membrane-protein complex consisting of 20 different subunits with a total molecular mass of 350 kDa for a monomer. It catalyses light-driven water oxidation at its catalytic centre, the oxygen-evolving complex (OEC). The structure of PSII has been analysed at 1.9 Å resolution by synchrotron radiation X-rays, which revealed that the OEC is a Mn4CaO5 cluster organized in an asymmetric, 'distorted-chair' form. This structure was further analysed with femtosecond X-ray free electron lasers (XFEL), providing the 'radiation damage-free' structure. The mechanism of O=O bond formation, however, remains obscure owing to the lack of intermediate-state structures. Here we describe the structural changes in PSII induced by two-flash illumination at room temperature at a resolution of 2.35 Å using time-resolved serial femtosecond crystallography with an XFEL provided by the SPring-8 ångström compact free-electron laser. An isomorphous difference Fourier map between the two-flash and dark-adapted states revealed two areas of apparent changes: around the QB/non-haem iron and the Mn4CaO5 cluster. The changes around the QB/non-haem iron region reflected the electron and proton transfers induced by the two-flash illumination. In the region around the OEC, a water molecule located 3.5 Å from the Mn4CaO5 cluster disappeared from the map upon two-flash illumination. This reduced the distance between another water molecule and the oxygen atom O4, suggesting that proton transfer also occurred. Importantly, the two-flash-minus-dark isomorphous difference Fourier map showed an apparent positive peak around O5, a unique μ4-oxo-bridge located in the quasi-centre of Mn1 and Mn4 (refs 4,5). This suggests the insertion of a new oxygen atom (O6) close to O5, providing an O=O distance of 1.5 Å between these two oxygen atoms. This provides a mechanism for the O=O bond formation consistent with that proposed previously.
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38
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Sjöholm J, Ho F, Ahmadova N, Brinkert K, Hammarström L, Mamedov F, Styring S. The protonation state around Tyr D /Tyr D • in photosystem II is reflected in its biphasic oxidation kinetics. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:147-155. [DOI: 10.1016/j.bbabio.2016.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 10/31/2016] [Accepted: 11/02/2016] [Indexed: 10/20/2022]
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39
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Morris JN, Eaton-Rye JJ, Summerfield TC. Environmental pH and the Requirement for the Extrinsic Proteins of Photosystem II in the Function of Cyanobacterial Photosynthesis. FRONTIERS IN PLANT SCIENCE 2016; 7:1135. [PMID: 27555848 PMCID: PMC4977308 DOI: 10.3389/fpls.2016.01135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2016] [Accepted: 07/18/2016] [Indexed: 06/06/2023]
Abstract
In one of the final stages of cyanobacterial Photosystem II (PS II) assembly, binding of up to four extrinsic proteins to PS II stabilizes the oxygen-evolving complex (OEC). Growth of cyanobacterial mutants deficient in certain combinations of these thylakoid-lumen-associated polypeptides is sensitive to changes in environmental pH, despite the physical separation of the membrane-embedded PS II complex from the external environment. In this perspective we discuss the effect of environmental pH on OEC function and photoautotrophic growth in cyanobacteria with reference to pH-sensitive PS II mutants lacking extrinsic proteins. We consider the possibilities that, compared to pH 10.0, pH 7.5 increases susceptibility to PS II-generated reactive oxygen species (ROS) causing photoinhibition and reducing PS II assembly in some mutants, and that perturbations to channels in the lumenal regions of PS II might alter the accessibility of water to the active site as well as egress of oxygen and protons to the thylakoid lumen. Reduced levels of PS II in these mutants, and reduced OEC activity arising from the disruption of substrate/product channels, could reduce the trans-thylakoid pH gradient (ΔpH), leading to the impairment of photosynthesis. Growth of some PS II mutants at pH 7.5 can be rescued by elevating CO2 levels, suggesting that the pH-sensitive phenotype might primarily be an indirect result of back-pressure in the electron transport chain that results in heightened production of ROS by the impaired photosystem.
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Affiliation(s)
- Jaz N. Morris
- Department of Botany, University of OtagoDunedin, New Zealand
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40
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Oldemeyer S, Franz S, Wenzel S, Essen LO, Mittag M, Kottke T. Essential Role of an Unusually Long-lived Tyrosyl Radical in the Response to Red Light of the Animal-like Cryptochrome aCRY. J Biol Chem 2016; 291:14062-14071. [PMID: 27189948 DOI: 10.1074/jbc.m116.726976] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Indexed: 11/06/2022] Open
Abstract
Cryptochromes constitute a group of flavin-binding blue light receptors in bacteria, fungi, plants, and insects. Recently, the response of cryptochromes to light was extended to nearly the entire visible spectral region on the basis of the activity of the animal-like cryptochrome aCRY in the green alga Chlamydomonas reinhardtii This finding was explained by the absorption of red light by the flavin neutral radical as the dark state of the receptor, which then forms the anionic fully reduced state. In this study, time-resolved UV-visible spectroscopy on the full-length aCRY revealed an unusually long-lived tyrosyl radical with a lifetime of 2.6 s, which is present already 1 μs after red light illumination of the flavin radical. Mutational studies disclosed the tyrosine 373 close to the surface to form the long-lived radical and to be essential for photoreduction. This residue is conserved exclusively in the sequences of other putative aCRY proteins distinguishing them from conventional (6-4) photolyases. Size exclusion chromatography showed the full-length aCRY to be a dimer in the dark at 0.5 mm injected concentration with the C-terminal extension as the dimerization site. Upon illumination, partial oligomerization was observed via disulfide bridge formation at cysteine 482 in close proximity to tyrosine 373. The lack of any light response in the C-terminal extension as evidenced by FTIR spectroscopy differentiates aCRY from plant and Drosophila cryptochromes. These findings imply that aCRY might have evolved a different signaling mechanism via a light-triggered redox cascade culminating in photooxidation of a yet unknown substrate or binding partner.
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Affiliation(s)
- Sabine Oldemeyer
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld
| | - Sophie Franz
- Structural Biochemistry, Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straβe 4, 35039 Marburg
| | - Sandra Wenzel
- Institute of General Botany and Plant Physiology, Friedrich Schiller University, Am Planetarium 1, 07743 Jena, Germany
| | - Lars-Oliver Essen
- Structural Biochemistry, Department of Chemistry, Philipps University Marburg, Hans-Meerwein Straβe 4, 35039 Marburg
| | - Maria Mittag
- Institute of General Botany and Plant Physiology, Friedrich Schiller University, Am Planetarium 1, 07743 Jena, Germany
| | - Tilman Kottke
- Physical and Biophysical Chemistry, Department of Chemistry, Bielefeld University, Universitätsstr. 25, 33615 Bielefeld,.
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Najafpour MM, Renger G, Hołyńska M, Moghaddam AN, Aro EM, Carpentier R, Nishihara H, Eaton-Rye JJ, Shen JR, Allakhverdiev SI. Manganese Compounds as Water-Oxidizing Catalysts: From the Natural Water-Oxidizing Complex to Nanosized Manganese Oxide Structures. Chem Rev 2016; 116:2886-936. [PMID: 26812090 DOI: 10.1021/acs.chemrev.5b00340] [Citation(s) in RCA: 337] [Impact Index Per Article: 42.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
All cyanobacteria, algae, and plants use a similar water-oxidizing catalyst for water oxidation. This catalyst is housed in Photosystem II, a membrane-protein complex that functions as a light-driven water oxidase in oxygenic photosynthesis. Water oxidation is also an important reaction in artificial photosynthesis because it has the potential to provide cheap electrons from water for hydrogen production or for the reduction of carbon dioxide on an industrial scale. The water-oxidizing complex of Photosystem II is a Mn-Ca cluster that oxidizes water with a low overpotential and high turnover frequency number of up to 25-90 molecules of O2 released per second. In this Review, we discuss the atomic structure of the Mn-Ca cluster of the Photosystem II water-oxidizing complex from the viewpoint that the underlying mechanism can be informative when designing artificial water-oxidizing catalysts. This is followed by consideration of functional Mn-based model complexes for water oxidation and the issue of Mn complexes decomposing to Mn oxide. We then provide a detailed assessment of the chemistry of Mn oxides by considering how their bulk and nanoscale properties contribute to their effectiveness as water-oxidizing catalysts.
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Affiliation(s)
| | - Gernot Renger
- Institute of Chemistry, Max-Volmer-Laboratory of Biophysical Chemistry, Technical University Berlin , Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Małgorzata Hołyńska
- Fachbereich Chemie und Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg , Hans-Meerwein-Straße, D-35032 Marburg, Germany
| | | | - Eva-Mari Aro
- Department of Biochemistry and Food Chemistry, University of Turku , 20014 Turku, Finland
| | - Robert Carpentier
- Groupe de Recherche en Biologie Végétale (GRBV), Université du Québec à Trois-Rivières , C.P. 500, Trois-Rivières, Québec G9A 5H7, Canada
| | - Hiroshi Nishihara
- Department of Chemistry, School of Science, The University of Tokyo , 7-3-1, Hongo, Bunkyo-Ku, Tokyo 113-0033, Japan
| | - Julian J Eaton-Rye
- Department of Biochemistry, University of Otago , P.O. Box 56, Dunedin 9054, New Zealand
| | - Jian-Ren Shen
- Photosynthesis Research Center, Graduate School of Natural Science and Technology, Faculty of Science, Okayama University , Okayama 700-8530, Japan.,Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences , Beijing 100093, China
| | - Suleyman I Allakhverdiev
- Controlled Photobiosynthesis Laboratory, Institute of Plant Physiology, Russian Academy of Sciences , Botanicheskaya Street 35, Moscow 127276, Russia.,Institute of Basic Biological Problems, Russian Academy of Sciences , Pushchino, Moscow Region 142290, Russia.,Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University , Leninskie Gory 1-12, Moscow 119991, Russia
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42
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Saito K, Sakashita N, Ishikita H. Energetics of the Proton Transfer Pathway for Tyrosine D in Photosystem II. Aust J Chem 2016. [DOI: 10.1071/ch16248] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The proton transfer pathway for redox active tyrosine D (TyrD) in photosystem II is a hydrogen-bond network that involves D2-Arg180 and a series of water molecules. Using quantum mechanical/molecular mechanical calculations, the detailed properties of the energetics and structural geometries were investigated. The potential-energy profile of all hydrogen bonds along the proton transfer pathway indicates that the overall proton transfer from TyrD is energetically downhill. D2-Arg180 plays a key role in the proton transfer pathway, providing a driving force for proton transfer, maintaining the hydrogen-bond network structure, stabilising P680•+, and thus deprotonating TyrD-OH to TyrD-O•. A hydrophobic environment near TyrD enhances the electrostatic interactions between TyrD and redox active groups, e.g. P680 and the catalytic Mn4CaO5 cluster: the redox states of those groups are linked with the protonation state of TyrD, i.e. release of the proton from TyrD. Thus, the proton transfer pathway from TyrD may ultimately contribute to the conversion of S0 into S1 in the dark in order to stabilise the Mn4CaO5 cluster when the photocycle is interrupted in S0.
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43
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Temperature dependence of the oxidation kinetics of TyrZ and TyrD in oxygen-evolving photosystem II complexes throughout the range from 320K to 5K. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:1283-96. [DOI: 10.1016/j.bbabio.2015.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 07/10/2015] [Accepted: 07/15/2015] [Indexed: 11/21/2022]
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44
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Nakamura S, Noguchi T. Infrared Detection of a Proton Released from Tyrosine YD to the Bulk upon Its Photo-oxidation in Photosystem II. Biochemistry 2015; 54:5045-53. [PMID: 26241205 DOI: 10.1021/acs.biochem.5b00568] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photosystem II (PSII) has two symmetrically located, redox-active tyrosine residues, YZ and YD. Whereas YZ mediates the electron transfer from the water-oxidizing center to P680 in the main electron transfer pathway, YD functions as a peripheral electron donor to P680. To understand the mechanism of this functional difference between YZ and YD, it is essential to know where the proton is transferred upon its oxidation in the proton-coupled electron transfer process. In this study, we used Fourier transform infrared (FTIR) spectroscopy to examine whether the proton from YD is released from the protein into the bulk. The proton detection method previously used for water oxidation in PSII [Suzuki et al. (2009) J. Am. Chem. Soc. 131, 7849-7857] was applied to YD; a proton released into the bulk upon YD oxidation was trapped by a high-concentration Mes buffer, and the protonation reaction of Mes was monitored by FTIR difference spectroscopy. It was shown that 0.84 ± 0.10 protons are released into the bulk by oxidation of YD in one PSII center. This result indicates that the proton of YD is not transferred to the neighboring D2-His198 but is released from the protein; this is in sharp contrast to the YZ reaction, in which a proton is transferred to D1-His190 through a strong hydrogen bond. This functional difference is caused by differences in the hydrogen-bonded structures of YD and YZ, which are determined by the hydrogen bond partners at the Nπ sites of these His residues, i.e., D2-Arg294 and D1-Asn298, which function as a hydrogen bond donor and acceptor, respectively. This FTIR spectroscopy result supports the recent theoretical prediction [Saito et al. (2013) Proc. Natl. Acad. Sci. U.S.A. 110, 7690-7695] based on the X-ray crystallographic structure of PSII and explains the different rates of the redox reactions of YD and YZ.
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Affiliation(s)
- Shin Nakamura
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
| | - Takumi Noguchi
- Division of Material Science, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8602, Japan
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45
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Retegan M, Cox N, Lubitz W, Neese F, Pantazis DA. The first tyrosyl radical intermediate formed in the S2-S3 transition of photosystem II. Phys Chem Chem Phys 2015; 16:11901-10. [PMID: 24760184 DOI: 10.1039/c4cp00696h] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The EPR "split signals" represent key intermediates of the S-state cycle where the redox active D1-Tyr161 (YZ) has been oxidized by the reaction center of the photosystem II enzyme to its tyrosyl radical form, but the successive oxidation of the Mn4CaO5 cluster has not yet occurred (SiYZ˙). Here we focus on the S2YZ˙ state, which is formed en route to the final metastable state of the catalyst, the S3 state, the state which immediately precedes O-O bond formation. Quantum chemical calculations demonstrate that both isomeric forms of the S2 state, the open and closed cubane isomers, can form states with an oxidized YZ˙ residue without prior deprotonation of the Mn4CaO5 cluster. The two forms are expected to lie close in energy and retain the electronic structure and magnetic topology of the corresponding S2 state of the inorganic core. As expected, tyrosine oxidation results in a proton shift towards His190. Analysis of the electronic rearrangements that occur upon formation of the tyrosyl radical suggests that a likely next step in the catalytic cycle is the deprotonation of a terminal water ligand (W1) of the Mn4CaO5 cluster. Diamagnetic metal ion substitution is used in our calculations to obtain the molecular g-tensor of YZ˙. It is known that the gx value is a sensitive probe not only of the extent of the proton shift between the tyrosine-histidine pair, but also of the polarization environment of the tyrosine, especially about the phenolic oxygen. It is shown for PSII that this environment is determined by the Ca(2+) ion, which locates two water molecules about the phenoxyl oxygen, indirectly modulating the oxidation potential of YZ.
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Affiliation(s)
- Marius Retegan
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-38, 45470 Mülheim an der Ruhr, Germany.
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46
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Boussac A, Rutherford AW, Sugiura M. Electron transfer pathways from the S2-states to the S3-states either after a Ca2+/Sr2+ or a Cl-/I- exchange in Photosystem II from Thermosynechococcus elongatus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:576-86. [PMID: 25843552 DOI: 10.1016/j.bbabio.2015.03.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Revised: 03/25/2015] [Accepted: 03/29/2015] [Indexed: 01/12/2023]
Abstract
The site for water oxidation in Photosystem II (PSII) goes through five sequential oxidation states (S0 to S4) before O2 is evolved. It consists of a Mn4CaO5-cluster close to a redox-active tyrosine residue (YZ). Cl- is also required for enzyme activity. By using EPR spectroscopy it has been shown that both Ca2+/Sr2+ exchange and Cl-/I- exchange perturb the proportions of centers showing high (S=5/2) and low spin (S=1/2) forms of the S2-state. The S3-state was also found to be heterogeneous with: i) a S=3 form that is detectable by EPR and not sensitive to near-infrared light; and ii) a form that is not EPR visible but in which Mn photochemistry occurs resulting in the formation of a (S2YZ)' split EPR signal upon near-infrared illumination. In Sr/Cl-PSII, the high spin (S=5/2) form of S2 shows a marked heterogeneity with a g=4.3 form generated at low temperature that converts to a relaxed form at g=4.9 at higher temperatures. The high spin g=4.9 form can then progress to the EPR detectable form of S3 at temperatures as low as 180K whereas the low spin (S=1/2) S2-state can only advance to the S3 state at temperatures≥235 K. Both of the two S2 configurations and the two S3 configurations are each shown to be in equilibrium at ≥235 K but not at 198 K. Since both S2 configurations are formed at 198 K, they likely arise from two specific populations of S1. The existence of heterogeneous populations in S1, S2 and S3 states may be related to the structural flexibility associated with the positioning of the oxygen O5 within the cluster highlighted in computational approaches and which has been linked to substrate exchange. These data are discussed in the context of recent in silico studies of the electron transfer pathways between the S2-state(s) and the S3-state(s).
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Affiliation(s)
- Alain Boussac
- I(2)BC, CNRS UMR 9198, CEA Saclay, 91191 Gif-sur-Yvette, France.
| | | | - Miwa Sugiura
- Proteo-Science Research Center, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan; Department of Chemistry, Graduate School of Science and Technology, Ehime University, Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan; PRESTO, Japan Science and Technology Agency (JST), 4-1-8, Honcho, Kawaguchi, Saitama 332-0012, Japan
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47
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Sjöholm J, Mamedov F, Styring S. Spectroscopic Evidence for a Redox-Controlled Proton Gate at Tyrosine D in Photosystem II. Biochemistry 2014; 53:5721-3. [DOI: 10.1021/bi5009672] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Johannes Sjöholm
- Molecular Biomimetics, Department
of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 523, SE-751 20 Uppsala, Sweden
| | - Fikret Mamedov
- Molecular Biomimetics, Department
of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 523, SE-751 20 Uppsala, Sweden
| | - Stenbjörn Styring
- Molecular Biomimetics, Department
of Chemistry-Ångström Laboratory, Uppsala University, P.O. Box 523, SE-751 20 Uppsala, Sweden
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48
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Glover SD, Jorge C, Liang L, Valentine KG, Hammarström L, Tommos C. Photochemical tyrosine oxidation in the structurally well-defined α3Y protein: proton-coupled electron transfer and a long-lived tyrosine radical. J Am Chem Soc 2014; 136:14039-51. [PMID: 25121576 PMCID: PMC4195373 DOI: 10.1021/ja503348d] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
![]()
Tyrosine oxidation–reduction involves proton-coupled electron
transfer (PCET) and a reactive radical state. These properties are
effectively controlled in enzymes that use tyrosine as a high-potential,
one-electron redox cofactor. The α3Y model protein
contains Y32, which can be reversibly oxidized and reduced in voltammetry
measurements. Structural and kinetic properties of α3Y are presented. A solution NMR structural analysis reveals that
Y32 is the most deeply buried residue in α3Y. Time-resolved
spectroscopy using a soluble flash-quench generated [Ru(2,2′-bipyridine)3]3+ oxidant provides high-quality Y32–O•
absorption spectra. The rate constant of Y32 oxidation (kPCET) is pH dependent: 1.4 × 104 M–1 s–1 (pH 5.5), 1.8 × 105 M–1 s–1 (pH 8.5), 5.4
× 103 M–1 s–1 (pD
5.5), and 4.0 × 104 M–1 s–1 (pD 8.5). kH/kD of Y32 oxidation is 2.5 ± 0.5 and 4.5 ± 0.9 at
pH(D) 5.5 and 8.5, respectively. These pH and isotope characteristics
suggest a concerted or stepwise, proton-first Y32 oxidation mechanism.
The photochemical yield of Y32–O• is 28–58% versus
the concentration of [Ru(2,2′-bipyridine)3]3+. Y32–O• decays slowly, t1/2 in the range of 2–10 s, at both pH 5.5 and 8.5,
via radical–radical dimerization as shown by second-order kinetics
and fluorescence data. The high stability of Y32–O•
is discussed relative to the structural properties of the Y32 site.
Finally, the static α3Y NMR structure cannot explain
(i) how the phenolic proton released upon oxidation is removed or
(ii) how two Y32–O• come together to form dityrosine.
These observations suggest that the dynamic properties of the protein
ensemble may play an essential role in controlling the PCET and radical
decay characteristics of α3Y.
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Affiliation(s)
- Starla D Glover
- Department of Chemistry, Ångström Laboratory, Uppsala University , Box 523, SE75120 Uppsala, Sweden
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Pathway for Mn-cluster oxidation by tyrosine-Z in the S2 state of photosystem II. Proc Natl Acad Sci U S A 2014; 111:8723-8. [PMID: 24889635 DOI: 10.1073/pnas.1401719111] [Citation(s) in RCA: 105] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Water oxidation in photosynthetic organisms occurs through the five intermediate steps S0-S4 of the Kok cycle in the oxygen evolving complex of photosystem II (PSII). Along the catalytic cycle, four electrons are subsequently removed from the Mn4CaO5 core by the nearby tyrosine Tyr-Z, which is in turn oxidized by the chlorophyll special pair P680, the photo-induced primary donor in PSII. Recently, two Mn4CaO5 conformations, consistent with the S2 state (namely, S2(A) and S2(B) models) were suggested to exist, perhaps playing a different role within the S2-to-S3 transition. Here we report multiscale ab initio density functional theory plus U simulations revealing that upon such oxidation the relative thermodynamic stability of the two previously proposed geometries is reversed, the S2(B) state becoming the leading conformation. In this latter state a proton coupled electron transfer is spontaneously observed at ∼100 fs at room temperature dynamics. Upon oxidation, the Mn cluster, which is tightly electronically coupled along dynamics to the Tyr-Z tyrosyl group, releases a proton from the nearby W1 water molecule to the close Asp-61 on the femtosecond timescale, thus undergoing a conformational transition increasing the available space for the subsequent coordination of an additional water molecule. The results can help to rationalize previous spectroscopic experiments and confirm, for the first time to our knowledge, that the water-splitting reaction has to proceed through the S2(B) conformation, providing the basis for a structural model of the S3 state.
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50
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Nakamura S, Nagao R, Takahashi R, Noguchi T. Fourier transform infrared detection of a polarizable proton trapped between photooxidized tyrosine YZ and a coupled histidine in photosystem II: relevance to the proton transfer mechanism of water oxidation. Biochemistry 2014; 53:3131-44. [PMID: 24786306 DOI: 10.1021/bi500237y] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The redox-active tyrosine YZ (D1-Tyr161) in photosystem II (PSII) functions as an immediate electron acceptor of the Mn4Ca cluster, which is the catalytic center of photosynthetic water oxidation. YZ is also located in the hydrogen bond network that connects the Mn4Ca cluster to the lumen and hence is possibly related to the proton transfer process during water oxidation. To understand the role of YZ in the water oxidation mechanism, we have studied the hydrogen bonding interactions of YZ and its photooxidized neutral radical YZ(•) together with the interaction of the coupled His residue, D1-His190, using light-induced Fourier transform infrared (FTIR) difference spectroscopy. The YZ(•)-minus-YZ FTIR difference spectrum of Mn-depleted PSII core complexes exhibited a broad positive feature around 2800 cm(-1), which was absent in the corresponding spectrum of another redox-active tyrosine YD (D2-Tyr160). Analyses by (15)N and H/D substitutions, examination of the pH dependence, and density functional theory and quantum mechanics/molecular mechanics (QM/MM) calculations showed that this band arises from the N-H stretching vibration of the protonated cation of D1-His190 forming a charge-assisted strong hydrogen bond with YZ(•). This result provides strong evidence that the proton released from YZ upon its oxidation is trapped in D1-His190 and a positive charge remains on this His. The broad feature of the ~2800 cm(-1) band reflects a large proton polarizability in the hydrogen bond between YZ(•) and HisH(+). QM/MM calculations further showed that upon YZ oxidation the hydrogen bond network is rearranged and one water molecule moves toward D1-His190. From these data, a novel proton transfer mechanism via YZ(•)-HisH(+) is proposed, in which hopping of the polarizable proton of HisH(+) to this water triggers the transfer of the proton from substrate water to the luminal side. This proton transfer mechanism could be functional in the S2 → S3 transition, which requires proton release before electron transfer because of an excess positive charge on the Mn4Ca cluster.
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Affiliation(s)
- Shin Nakamura
- Division of Material Science, Graduate School of Science, Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
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