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Zabelin AA, Shkuropatova VA, Makhneva ZK, Moskalenko AA, Shuvalov VA, Shkuropatov AY. Chemically modified reaction centers of photosystem II: Exchange of pheophytin a with 7-deformyl-7-hydroxymethyl-pheophytin b. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1870-1881. [DOI: 10.1016/j.bbabio.2014.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Revised: 08/14/2014] [Accepted: 08/19/2014] [Indexed: 11/28/2022]
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Vishnev MI, Zabelin AA, Shkuropatova VA, Yanyushin MF, Shuvalov VA, Shkuropatov AY. Chemical modification of photosystem II core complex pigments with sodium borohydride. BIOCHEMISTRY (MOSCOW) 2013; 78:377-84. [DOI: 10.1134/s0006297913040068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Acharya K, Neupane B, Zazubovich V, Sayre RT, Picorel R, Seibert M, Jankowiak R. Site energies of active and inactive pheophytins in the reaction center of Photosystem II from Chlamydomonas reinhardtii. J Phys Chem B 2012; 116:3890-9. [PMID: 22397491 DOI: 10.1021/jp3007624] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is widely accepted that the primary electron acceptor in various Photosystem II (PSII) reaction center (RC) preparations is pheophytin a (Pheo a) within the D1 protein (Pheo(D1)), while Pheo(D2) (within the D2 protein) is photochemically inactive. The Pheo site energies, however, have remained elusive, due to inherent spectral congestion. While most researchers over the past two decades placed the Q(y)-states of Pheo(D1) and Pheo(D2) bands near 678-684 and 668-672 nm, respectively, recent modeling [Raszewski et al. Biophys. J. 2005, 88, 986 - 998; Cox et al. J. Phys. Chem. B 2009, 113, 12364 - 12374] of the electronic structure of the PSII RC reversed the assignment of the active and inactive Pheos, suggesting that the mean site energy of Pheo(D1) is near 672 nm, whereas Pheo(D2) (~677.5 nm) and Chl(D1) (~680 nm) have the lowest energies (i.e., the Pheo(D2)-dominated exciton is the lowest excited state). In contrast, chemical pigment exchange experiments on isolated RCs suggested that both pheophytins have their Q(y) absorption maxima at 676-680 nm [Germano et al. Biochemistry 2001, 40, 11472 - 11482; Germano et al. Biophys. J. 2004, 86, 1664 - 1672]. To provide more insight into the site energies of both Pheo(D1) and Pheo(D2) (including the corresponding Q(x) transitions, which are often claimed to be degenerate at 543 nm) and to attest that the above two assignments are most likely incorrect, we studied a large number of isolated RC preparations from spinach and wild-type Chlamydomonas reinhardtii (at different levels of intactness) as well as the Chlamydomonas reinhardtii mutant (D2-L209H), in which the active branch Pheo(D1) is genetically replaced with chlorophyll a (Chl a). We show that the Q(x)-/Q(y)-region site energies of Pheo(D1) and Pheo(D2) are ~545/680 nm and ~541.5/670 nm, respectively, in good agreement with our previous assignment [Jankowiak et al. J. Phys. Chem. B 2002, 106, 8803 - 8814]. The latter values should be used to model excitonic structure and excitation energy transfer dynamics of the PSII RCs.
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Affiliation(s)
- K Acharya
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
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Noy D, Moser CC, Dutton PL. Design and engineering of photosynthetic light-harvesting and electron transfer using length, time, and energy scales. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:90-105. [PMID: 16457774 DOI: 10.1016/j.bbabio.2005.11.010] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2005] [Revised: 11/16/2005] [Accepted: 11/21/2005] [Indexed: 11/20/2022]
Abstract
Decades of research on the physical processes and chemical reaction-pathways in photosynthetic enzymes have resulted in an extensive database of kinetic information. Recently, this database has been augmented by a variety of high and medium resolution crystal structures of key photosynthetic enzymes that now include the two photosystems (PSI and PSII) of oxygenic photosynthetic organisms. Here, we examine the currently available structural and functional information from an engineer's point of view with the long-term goal of reproducing the key features of natural photosystems in de novo designed and custom-built molecular solar energy conversion devices. We find that the basic physics of the transfer processes, namely, the time constraints imposed by the rates of incoming photon flux and the various decay processes allow for a large degree of tolerance in the engineering parameters. Moreover, we find that the requirements to guarantee energy and electron transfer rates that yield high efficiency in natural photosystems are largely met by control of distance between chromophores and redox cofactors. Thus, for projected de novo designed constructions, the control of spatial organization of cofactor molecules within a dense array is initially given priority. Nevertheless, constructions accommodating dense arrays of different cofactors, some well within 1 nm from each other, still presents a significant challenge for protein design.
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Affiliation(s)
- Dror Noy
- Johnson Research Foundation, Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
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Krausz E, Hughes JL, Smith P, Pace R, Peterson Arsköld S. Oxygen-evolving Photosystem II core complexes: a new paradigm based on the spectral identification of the charge-separating state, the primary acceptor and assignment of low-temperature fluorescence. Photochem Photobiol Sci 2005; 4:744-53. [PMID: 16121287 DOI: 10.1039/b417905f] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We review our recent low-temperature absorption, circular dichroism (CD), magnetic CD (MCD), fluorescence and laser-selective measurements of oxygen-evolving Photosystem II (PSII) core complexes and their constituent CP 4 3, CP 47 and D1/D2/cytb(559) sub-assemblies. Quantitative comparisons reveal that neither absorption nor fluorescence spectra of core complexes are simple additive combinations of the spectra of the sub-assemblies. The absorption spectrum of the D1/D2/cytb(559) component embedded within the core complex appears significantly better structured and red-shifted compared to that of the isolated sub-assembly. A characteristic MCD reduction or 'deficit' is a useful signature for the central chlorins in the reaction centre. We note a congruence of the MCD deficit spectra of the isolated D1/D2/cytb(559) sub-assemblies to their laser-induced transient bleaches associated with P 680. A comparison of spectra of core complexes prepared from different organisms helps distinguish features due to inner light-harvesting assemblies and the central reaction-centre chlorins. Electrochromic spectral shifts in core complexes that occur following low-temperature illumination of active core complexes arise from efficient charge separation and subsequent plastoquinone anion (Q(A)(-)) formation. Such measurements allow determinations of both charge-separation efficiencies and spectral characteristics of the primary acceptor, Pheo(D1). Efficient charge separation occurs with excitation wavelengths as long as 700 nm despite the illuminations being performed at 1.7 K and with an extremely low level of incident power density. A weak, homogeneously broadened, charge-separating state of PSII lies obscured beneath the CP 47 state centered at 690 nm. We present new data in the 690-760 nm region, clearly identifying a band extending to 730 nm. Active core complexes show remarkably strong persistent spectral hole-burning activity in spectral regions attributable to CP 43 and CP 47. Measurements of homogeneous hole-widths have established that, at low temperatures, excitation transfer from these inner light-harvesting assemblies to the reaction centre occurs with approximately 70-270 ps(-1) rates, when the quinone acceptor is reduced. The rate is slower for lower-energy sub-populations of an inhomogeneously broadened antenna (trap) pigment. The complex low-temperature fluorescence behaviour seen in PSII is explicable in terms of slow excitation transfer from traps to the weak low-energy charge-separating state and transfer to the more intense reaction-centre excitations near 685 nm. The nature and origin of the charge-separating state in oxygen-evolving PSII preparations is briefly discussed.
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Affiliation(s)
- Elmars Krausz
- Research School of Chemistry, Australian National University, Canberra, Australia.
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Tomo T, Hirano E, Nagata J, Nakazato K. Pigment exchange of photosystem II reaction center by chlorophyll d. PHOTOSYNTHESIS RESEARCH 2005; 84:77-83. [PMID: 16049758 DOI: 10.1007/s11120-005-1302-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2004] [Accepted: 01/26/2005] [Indexed: 05/03/2023]
Abstract
Pigment exchanges among photosystem reaction centers (RCs) are useful for the identification and functional analysis of chromophores in photosynthetic organisms. Pigment replacement within the spinach Photosystem II RC was performed with Chl d derived from the oxygenic alga Acaryochloris marina, using a protocol similar to that reported previously [Gall et al. (1998) FEBS Lett 434: 88-92] based on the incubation of reaction centers with an excess of other pigments. In this study, we analyzed Chl d-modified monomeric RC which was separated from Chl d-modified dimeric RC by size-exclusion chromatography. Based on the assumption of a constant ratio of two Pheo a molecules per RC, the number of Chl a molecules in Chl d-modified monomeric RCs was found to decrease from six to four. The absorption spectrum of the Chl d-modified monomeric RC at room temperature showed a large peak at 699.5 nm originating from Chl d and a small peak at 672.5 nm orignating from Chl a. Photoaccumulation of the Pheo a- in Chl d-modified monomeric RC, in the presence of sodium dithionate and methyl viologen, did not differ significantly from that in control RC, showing that the Chl d-modified monomeric RC retains its charge separation activity and photochemically active Pheo a.
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Affiliation(s)
- Tatsuya Tomo
- Department of Physics, College of Humanities & Sciences, Nihon University, 3-25-40 Sakurajousui, Tokyo, 156-8550, Japan.
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Xiong L, Seibert M, Gusev AV, Wasielewski MR, Hemann C, Hille CR, Sayre RT. Substitution of a Chlorophyll into the Inactive Branch Pheophytin-Binding Site Impairs Charge Separation in Photosystem II. J Phys Chem B 2004. [DOI: 10.1021/jp040262d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ling Xiong
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Michael Seibert
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Alexey V. Gusev
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Michael R. Wasielewski
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Craig Hemann
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - C. Russ Hille
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
| | - Richard T. Sayre
- Departments of Plant Cellular and Molecular Biology and Molecular and Cellular Biochemistry, Ohio State University, Columbus, Ohio 43210, National Renewable Energy Laboratory, Golden, Colorado 80401, and Department of Chemistry, Northwestern University, Evanston, Illinois 60208
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Zehetner A, Scheer H, Siffel P, Vacha F. Photosystem II reaction center with altered pigment-composition: reconstitution of a complex containing five chlorophyll a per two pheophytin a with modified chlorophylls. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1556:21-8. [PMID: 12351215 DOI: 10.1016/s0005-2728(02)00282-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pigment-depleted Photosystem II reaction centers (PS II-RCs) from a higher plant (pea) containing five chlorophyll a (Chl) per two pheophytin a (Phe), were treated with Chl and several derivatives under exchange conditions [FEBS Lett. 434 (1998) 88]. The resulting reconstituted complexes were compared to those obtained by pigment exchange of "conventional" PS II-RCs containing six Chl per two Phe. (1) The extraction of one Chl is fully reversible. (2) The site of extraction is the same as the one into which previously extraneous pigments have been exchanged, most likely the peripheral D1-H118. (3) Introducing an efficient quencher (Ni-Chl) into this site results in only 25% reduction of fluorescence, indicating incomplete energy equilibration among the "core" and peripheral chlorophylls.
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Affiliation(s)
- Andrea Zehetner
- Department Biologie I-Botanik, Universität München, Menzinger Str. 67, D-80638, Munich, Germany
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Wang J, Gosztola D, Ruffle SV, Hemann C, Seibert M, Wasielewski MR, Hille R, Gustafson TL, Sayre RT. Functional asymmetry of photosystem II D1 and D2 peripheral chlorophyll mutants of Chlamydomonas reinhardtii. Proc Natl Acad Sci U S A 2002; 99:4091-6. [PMID: 11904453 PMCID: PMC122653 DOI: 10.1073/pnas.062056899] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2001] [Accepted: 01/31/2002] [Indexed: 11/18/2022] Open
Abstract
The peripheral accessory chlorophylls (Chls) of the photosystem II (PSII) reaction center (RC) are coordinated by a pair of symmetry-related histidine residues (D1-H118 and D2-H117). These Chls participate in energy transfer from the proximal antennae complexes (CP43 and CP47) to the RC core chromophores. In addition, one or both of the peripheral Chls are redox-active and participate in a low-quantum-yield electron transfer cycle around PSII. We demonstrate that conservative mutations of the D2-H117 residue result in decreased Chl fluorescence quenching efficiency attributed to reduced accumulation of the peripheral accessory Chl cation, Chl(Z)(+). In contrast, identical symmetry-related mutations at residue D1-H118 had no effect on Chl fluorescence yield or quenching kinetics. Mutagenesis of the D2-H117 residue also altered the line width of the Chl(Z)(+) EPR signal, but the line shape of the D1-H118Q mutant remained unchanged. The D1-H118 and D2-H117 mutations also altered energy transfer properties in PSII RCs. Unlike wild type or the D1-H118Q mutant, D2-H117N RCs exhibited a reduced CD doublet in the red region of Chl absorbance band, indicative of reduced energetic coupling between P680 and the peripheral accessory Chl. In addition, transient absorption measurements of D2-H117N RCs, excited on the blue side of the Chl absorbance band, exhibited a ( approximately 400 fs) pheophytin Q(X) band bleach lifetime component not seen in wild-type or D1-H118Q RCs. The origin of this component may be related to delayed fast-energy equilibration of the excited state between the core pigments of this mutant.
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Affiliation(s)
- Jun Wang
- Department of Plant Biology, Ohio State University, Columbus, OH 43210, USA
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Germano M, Shkuropatov AY, Permentier H, de Wijn R, Hoff AJ, Shuvalov VA, van Gorkom HJ. Pigment organization and their interactions in reaction centers of photosystem II: optical spectroscopy at 6 K of reaction centers with modified pheophytin composition. Biochemistry 2001; 40:11472-82. [PMID: 11560495 DOI: 10.1021/bi010439j] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Photosystem II reaction centers (RC) with selectively exchanged pheophytin (Pheo) molecules as described in [Germano, M., Shkuropatov, A. Ya., Permentier, H., Khatypov, R. A., Shuvalov, V. A., Hoff, A. J., and van Gorkom, H. J. (2000) Photosynth. Res. 64, 189-198] were studied by low-temperature absorption, linear and circular dichroism, and triplet-minus-singlet absorption-difference spectroscopy. The ratio of extinction coefficients epsilon(Pheo)/epsilon(Chl) for Q(Y) absorption in the RC is approximately 0.40 at 6 K and approximately 0.45 at room temperature. The presence of 2 beta-carotenes, one parallel and one perpendicular to the membrane plane, is confirmed. Absorption at 670 nm is due to the perpendicular Q(Y) transitions of the two peripheral chlorophylls (Chl) and not to either Pheo. The "core" pigments, two Pheo and four Chl absorb in the 676-685 nm range. Delocalized excited states as predicted by the "multimer model" are seen in the active branch. The inactive Pheo and the nearby Chl, however, mainly contribute localized transitions at 676 and 680 nm, respectively, although large CD changes indicate that exciton interactions are present on both branches. Replacement of the active Pheo prevents triplet formation, causes an LD increase at 676 and 681 nm, a blue-shift of 680 nm absorbance, and a bleach of the 685 nm exciton band. The triplet state is mainly localized on the Chl corresponding to B(A) in purple bacteria. Both Pheo Q(Y) transitions are oriented out of the membrane plane. Their Q(X) transitions are parallel to that plane, so that the Pheos in PSII are structurally similar to their homologues in purple bacteria.
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Affiliation(s)
- M Germano
- Biophysics Department, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
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Khatypov RA, Shkuropatova VA, Zvereva MG, Owens TG, Shuvalov VA. Reaction centers of photosystem II with a chemically-modified pigment composition: exchange of pheophytins with 13(1)-deoxo-13(1)-hydroxy-pheophytin a. FEBS Lett 1999; 450:163-7. [PMID: 10350078 DOI: 10.1016/s0014-5793(99)00486-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Isolated reaction centers of photosystem II with an altered pigment content were obtained by chemical exchange of the native pheophytin a molecules with externally added 13(1)-deoxo-13(1)-hydroxy-pheophytin a. Judged from a comparison of the absorption spectra and photochemical activities of exchanged and control reaction centers, 70-80% of the pheophytin molecules active in charge separation are replaced by 13(1)-deoxo-13(1)-hydroxy-pheophytin a after double application of the exchange procedure. The new molecule at the active branch was not active photochemically. This appears to be the first stable preparation in which a redox active chromophore of the reaction center of photosystem II was modified by chemical substitution. The data are compatible with the presence of an active and inactive branch of cofactors, as in bacterial reaction centers. Possible applications of the 13(1)-deoxo-13(1)-hydroxy-pheophytin a-exchanged preparation to the spectral and functional analysis of native reaction centers of photosystem II are discussed.
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