1
|
Zabelin AA, Neverov KV, Krasnovsky AA, Shkuropatova VA, Shuvalov VA, Shkuropatov AY. Characterization of the low-temperature triplet state of chlorophyll in photosystem II core complexes: Application of phosphorescence measurements and Fourier transform infrared spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:782-8. [PMID: 27040752 DOI: 10.1016/j.bbabio.2016.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 03/23/2016] [Accepted: 03/28/2016] [Indexed: 10/21/2022]
Abstract
Phosphorescence measurements at 77 K and light-induced FTIR difference spectroscopy at 95 K were applied to study of the triplet state of chlorophyll a ((3)Chl) in photosystem II (PSII) core complexes isolated from spinach. Using both methods, (3)Chl was observed in the core preparations with doubly reduced primary quinone acceptor QA. The spectral parameters of Chl phosphorescence resemble those in the isolated PSII reaction centers (RCs). The main spectral maximum and the lifetime of the phosphorescence corresponded to 955±1 nm and of 1.65±0.05 ms respectively; in the excitation spectrum, the absorption maxima of all core complex pigments (Chl, pheophytin a (Pheo), and β-carotene) were observed. The differential signal at 1667(-)/1628(+)cm(-1) reflecting a downshift of the stretching frequency of the 13(1)-keto C=O group of Chl was found to dominate in the triplet-minus-singlet FTIR difference spectrum of core complexes. Based on FTIR results and literature data, it is proposed that (3)Chl is mostly localized on the accessory chlorophyll that is in triplet equilibrium with P680. Analysis of the data suggests that the Chl triplet state responsible for the phosphorescence and the FTIR difference spectrum is mainly generated due to charge recombination in the reaction center radical pair P680(+)PheoD1(-), and the energy and temporal parameters of this triplet state as well as the molecular environment and interactions of the triplet-bearing Chl molecule are similar in the PSII core complexes and isolated PSII RCs.
Collapse
Affiliation(s)
- Alexey A Zabelin
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - Konstantin V Neverov
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr., 33, Moscow 119071, Russian Federation; Biology Department, M.V. Lomonosov Moscow State University, Vorobyovy Gory, Moscow 119992, Russian Federation
| | - Alexander A Krasnovsky
- A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninskii pr., 33, Moscow 119071, Russian Federation; Biology Department, M.V. Lomonosov Moscow State University, Vorobyovy Gory, Moscow 119992, Russian Federation
| | - Valentina A Shkuropatova
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - Vladimir A Shuvalov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation
| | - Anatoly Ya Shkuropatov
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russian Federation.
| |
Collapse
|
2
|
Nadtochenko VA, Shelaev IV, Mamedov MD, Shkuropatov AY, Semenov AY, Shuvalov VA. Primary radical ion pairs in photosystem II core complexes. BIOCHEMISTRY (MOSCOW) 2014; 79:197-204. [PMID: 24821445 DOI: 10.1134/s0006297914030043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Ultrafast absorption spectroscopy with 20-fs resolution was applied to study primary charge separation in spinach photosystem II (PSII) reaction center (RC) and PSII core complex (RC complex with integral antenna) upon excitation at maximum wavelength 700-710 nm at 278 K. It was found that the initial charge separation between P680* and ChlD1 (Chl-670) takes place with a time constant of ~1 ps with the formation of the primary charge-separated state P680* with an admixture of: P680*((1-δ)) (P680(δ+)ChlD1(δ-)), where δ ~ 0.5. The subsequent electron transfer from P680(δ+)ChlD1(δ-) to pheophytin (Pheo) occurs within 13 ps and is accompanied by a relaxation of the absorption band at 670 nm (ChlD1(δ-)) and bleaching of the PheoD1 bands at 420, 545, and 680 nm with development of the Pheo(-) band at 460 nm. Further electron transfer to QA occurs within 250 ps in accordance with earlier data. The spectra of P680(+) and Pheo(-) formation include a bleaching band at 670 nm; this indicates that Chl-670 is an intermediate between P680 and Pheo. Stimulated emission kinetics at 685 nm demonstrate the existence of two decaying components with time constants of ~1 and ~13 ps due to the formation of P680(δ+)ChlD1(δ-) and P680(+)PheoD1(-), respectively.
Collapse
Affiliation(s)
- V A Nadtochenko
- Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, 119991, Russia
| | | | | | | | | | | |
Collapse
|
3
|
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]
|
4
|
Nadtochenko VA, Semenov AY, Shuvalov VA. Formation and decay of P680 (P(D1)-P(D2))⁺PheoD1⁻ radical ion pair in photosystem II core complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1384-8. [PMID: 24513193 DOI: 10.1016/j.bbabio.2014.01.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2013] [Revised: 01/10/2014] [Accepted: 01/31/2014] [Indexed: 11/18/2022]
Abstract
Under physiological conditions (278 K) femtosecond pump-probe laser spectroscopy with 20-fs time resolution was applied to study primary charge separation in spinach photosystem II (PSII) core complexes excited at 710 nm. It was shown that initial formation of anion radical band of pheophytin molecule (Pheo⁻) at 460 nm is observed with rise time of ~11ps. The kinetics of the observed rise was ascribed to charge separation between Chl (chlorophyll a) dimer, primary electron donor in PSII (P680*) and Pheo located in D1 protein subunit (PheoD1) absorbing at 420 nm, 545 nm and 680 nm with formation of the ion-radical pair P680⁺PheoDI⁻. The subsequent electron transfer from Pheo(D1)⁻ to primary plastoquinone electron acceptor (Q(A)) was accompanied by relaxation of the 460-nm band and occurred within ~250 ps in good agreement with previous measurements in Photosystem II-enriched particles and bacterial reaction centers. The subtraction of the P680⁺ spectrum measured at 455 ps delay from the spectra at 23 ps or 44 ps delay reveals the spectrum of Pheo(DI)⁻, which is very similar to that measured earlier by accumulation method. The spectrum of Pheo(DI)⁻ formation includes a bleaching (or red shift) of the 670 nm band indicating that Chl-670 is close to Pheo(D1). According to previous measurements in the femtosecond-picosecond time range this Chl-670 was ascribed to Chl(D1) [Shelaev, Gostev, Vishnev, Shkuropatov, Ptushenko, Mamedov, Sarkisov, Nadtochenko, Semenov and Shuvalov, J. Photochemistry and Photobiology, B: Biology 104 (2011) 45-50]. Stimulated emission at 685 nm was found to have two decaying components with time constants of ~1ps and ~14ps. These components appear to reflect formation of P680⁺Chl(D1)⁻ and P680⁺Pheo(D1)⁻, respectively, as found earlier. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
Collapse
Affiliation(s)
- V A Nadtochenko
- NN Semenov Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia
| | - A Yu Semenov
- NN Semenov Institute of Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Russia; A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, 119991 Moscow, Russia
| | - V A Shuvalov
- A.N. Belozersky Institute of Physical-Chemical Biology, Moscow State University, 119991 Moscow, Russia; Institute of Basic Biological Problems, Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russia.
| |
Collapse
|
5
|
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]
|
6
|
P680 (PD1PD2) and ChlD1 as alternative electron donors in photosystem II core complexes and isolated reaction centers. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 104:44-50. [DOI: 10.1016/j.jphotobiol.2011.02.003] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Revised: 01/25/2011] [Accepted: 02/03/2011] [Indexed: 12/13/2022]
|
7
|
Shelaev IV, Gostev FE, Nadtochenko VA, Shkuropatov AY, Zabelin AA, Mamedov MD, Semenov AY, Sarkisov OM, Shuvalov VA. Primary light-energy conversion in tetrameric chlorophyll structure of photosystem II and bacterial reaction centers: II. Femto- and picosecond charge separation in PSII D1/D2/Cyt b559 complex. PHOTOSYNTHESIS RESEARCH 2008; 98:95-103. [PMID: 18855113 DOI: 10.1007/s11120-008-9371-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2008] [Accepted: 09/15/2008] [Indexed: 05/26/2023]
Abstract
In Part I of the article, a review of recent data on electron-transfer reactions in photosystem II (PSII) and bacterial reaction center (RC) has been presented. In Part II, transient absorption difference spectroscopy with 20-fs resolution was applied to study the primary charge separation in PSII RC (DI/DII/Cyt b 559 complex) excited at 700 nm at 278 K. It was shown that the initial electron-transfer reaction occurs within 0.9 ps with the formation of the charge-separated state P680(+)Chl(D1)(-), which relaxed within 14 ps as indicated by reversible bleaching of 670-nm band that was tentatively assigned to the Chl(D1) absorption. The subsequent electron transfer from Chl(D1)(-) within 14 ps was accompanied by a development of the radical anion band of Pheo(D1) at 445 nm, attributable to the formation of the secondary radical pair P680(+)Pheo(D1)(-). The key point of this model is that the most blue Q(y) transition of Chl(D1) in RC is allowing an effective stabilization of separated charges. Although an alternative mechanism of charge separation with Chl(D1)* as a primary electron donor and Pheo(D1) as a primary acceptor can not be ruled out, it is less consistent with the kinetics and spectra of absorbance changes induced in the PSII RC preparation by femtosecond excitation at 700 nm.
Collapse
Affiliation(s)
- I V Shelaev
- NN Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117991 Moscow, Russia
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Spectroelectrochemistry of cytochromeb559 in the D1-D2-Cytb559 complex from spinach. FEBS Lett 2008; 582:1490-4. [PMID: 18396158 DOI: 10.1016/j.febslet.2008.03.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2008] [Revised: 03/05/2008] [Accepted: 03/21/2008] [Indexed: 11/23/2022]
|
9
|
Stewart DH, Nixon PJ, Diner BA, Brudvig GW. Assignment of the Qy absorbance bands of photosystem II chromophores by low-temperature optical spectroscopy of wild-type and mutant reaction centers. Biochemistry 2000; 39:14583-94. [PMID: 11087414 DOI: 10.1021/bi001246j] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Photosystem II (PSII) contains a collection of pheophytins (Pheo) and chlorophylls (Chl) that have unique absorbance spectra depending on their electronic structure and the surrounding protein environment. Despite numerous efforts to identify the spectra of each cofactor, differing assignments of the chromophore absorbance bands and electrochromic effects have led to conflicting models of pigment organization and chromophore interactions in PSII. We have utilized low-temperature measurements on well-defined redox states, together with the use of site-directed mutants, to make spectral assignments of several reaction center (RC) chromophores. Cryogenic (77 K) optical spectroscopy has been used to trap the bound redox-active quinone, Q(A), in the reduced form and measure the effect of the redox state of Q(A) on PSII chromophores without interference from other redox-active cofactors. The Q(A)(-) minus Q(A) difference spectrum contains a number of features that represent the perturbation of Pheo and Chl absorbance bands upon Q(A) reduction. Using site-directed mutants in which the axial ligand of the D1-side monomeric core Chl, P(A), is changed (D1-H198Q) or the hydrogen-bonding environment of the D1-side Pheo is modified (D1-Q130E), we have assigned the Q(y)() absorbance bands of four chromophores shifted by Q(A) reduction including both RC Pheos, the D1-side monomeric accessory Chl (B(A)), and one other Chl in PSII. The absorbance maximum of B(A) was identified at 683.5 nm from least-squares fits of the D1-H198Q minus wild type (WT) Q(A)(-) minus Q(A) double-difference spectrum; this assignment provides new evidence of a secondary effect of site-directed mutation on a RC chromophore. The other chromophores were assigned from simultaneous fits of the WT and D1-Q130E spectra in which the parameters of only the D1-side Pheo were allowed to vary. The D1-side and D2-side Pheos were found to have lambda(max) values at 685.6 and 669.3 nm, respectively, and another Chl influenced by Q(A)(-) was identified at 678.8 nm. These assignments are in good agreement with previous spectral analyses of intact PSII preparations and reveal that the number of chromophores affected by Q(A) reduction has been underestimated previously. In addition, the assignments are generally consistent with chromophore positions that are similar in the PSII RC and the bacterial photosynthetic RC.
Collapse
Affiliation(s)
- D H Stewart
- Sterling Chemistry Laboratory, Yale University, P.O. Box 208107, New Haven, Connecticut 06520-8107, USA
| | | | | | | |
Collapse
|
10
|
Kaminskaya O, Kurreck J, Irrgang KD, Renger G, Shuvalov VA. Redox and spectral properties of cytochrome b559 in different preparations of photosystem II. Biochemistry 1999; 38:16223-35. [PMID: 10587445 DOI: 10.1021/bi991257g] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A detailed analysis of the properties of cytochrome b(559) (Cyt b(559)) in photosystem II (PS II) preparations with different degrees of structural complexity is presented. It reveals that (i) D1-D2-Cyt b(559) complexes either in solubilized form or incorporated into liposomes contain only one type of Cyt b(559) with E(m) values of 60 +/- 5 and 100 +/- 10 mV, respectively, at pH 6.8; (ii) in oxygen-evolving solubilized PS II core complexes Cyt b(559) exists predominantly (>85%) as an LP form with an E(m,7) of 125 +/- 10 mV and a minor fraction with an E(m,7) of -150 +/- 15 mV; (iii) in oxygen-evolving PS II membrane fragments three different redox forms are discernible with E(m) values of 390 +/- 15 mV (HP form), 230 +/- 20 mV (IP form), and 105 +/- 25 mV (LP form) and relative amplitudes of 58, 24, and 18%, respectively, at pH 7.3; (iv) the E(m) values are almost pH-independent between pH 6 and 9.5 in all sample types except D1-D2-Cyt b(559) complexes incorporated into liposomes with a slope of -29 mV/pH unit, when the pH increases from 6 to 9.5 (IP and LP form in PS II membrane fragments possibly within a restricted range from pH 6.5 to 8); (v) at pH >8 the HP Cyt b(559) progressively converts to the IP form with increasing pH; (vi) the reduced-minus-oxidized optical difference spectra of Cyt b(559) are very similar in the lambda range of 360-700 nm for all types except for the HP form which exhibits pronounced differences in the Soret band; and (vii) PS II membrane fragments and core complexes are inferred to contain about two Cyt b(559) hemes per PS II. Possible implications of conformational changes near the heme group and spin state transitions of the iron are discussed.
Collapse
Affiliation(s)
- O Kaminskaya
- Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region.
| | | | | | | | | |
Collapse
|
11
|
Jankowiak R, Rätsep M, Picorel R, Seibert M, Small GJ. Excited States of the 5-Chlorophyll Photosystem II Reaction Center. J Phys Chem B 1999. [DOI: 10.1021/jp9906738] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R. Jankowiak
- Ames Laboratory−U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, Apdo. 202, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, Golden, Colorado 80401
| | - M. Rätsep
- Ames Laboratory−U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, Apdo. 202, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, Golden, Colorado 80401
| | - R. Picorel
- Ames Laboratory−U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, Apdo. 202, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, Golden, Colorado 80401
| | - M. Seibert
- Ames Laboratory−U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, Apdo. 202, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, Golden, Colorado 80401
| | - G. J. Small
- Ames Laboratory−U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, Apdo. 202, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, Golden, Colorado 80401
| |
Collapse
|
12
|
|
13
|
Affiliation(s)
- D H Stewart
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | | |
Collapse
|
14
|
Shkuropatov AY, Khatypov RA, Volshchukova TS, Shkuropatova VA, Owens TG, Shuvalov VA. Spectral and photochemical properties of borohydride-treated D1-D2-cytochrome b-559 complex of photosystem II. FEBS Lett 1997; 420:171-4. [PMID: 9459304 DOI: 10.1016/s0014-5793(97)01512-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The D1-D2-cytochrome b-559 reaction center complex of photosystem II with an altered pigment composition was prepared from the original complex by treatment with sodium borohydride (BH4-). The absorption spectra of the modified and original complexes were compared to each other and to the spectra of purified chlorophyll a and pheophytin a (Pheo a) treated with BH4- in methanolic solution. The results of these comparisons are consistent with the presence in the modified complex of an irreversibly reduced Pheo a molecule, most likely 13(1)-deoxo-13(1)-hydroxy-Pheo a, replacing one of the two native Pheo a molecules present in the original complex. Similar to the original preparation, the modified complex was capable of a steady-state photoaccumulation of Pheo- and P680+. It is concluded that the pheophytin a molecule which undergoes borohydride reduction is not involved in the primary charge separation and seems to represent a previously postulated photochemically inactive Pheo a molecule. The Qy and Qx transitions of this molecule were determined to be located at 5 degrees C at 679.5-680 nm and 542 nm, respectively.
Collapse
Affiliation(s)
- A Y Shkuropatov
- Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, Pushchino, Moscow Region, Russian Federation.
| | | | | | | | | | | |
Collapse
|
15
|
Xiong J, Subramaniam S. Modeling of the D1/D2 proteins and cofactors of the photosystem II reaction center: implications for herbicide and bicarbonate binding. Protein Sci 1996; 5:2054-73. [PMID: 8897606 PMCID: PMC2143261 DOI: 10.1002/pro.5560051012] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A three-dimensional model of the photosystem II (PSII) reaction center from the cyanobacterium Synechocystis sp. PCC 6803 was generated based on homology with the anoxygenic purple bacterial photosynthetic reaction centers of Rhodobacter sphaeroides and Rhodopseudomonas viridis, for which the X-ray crystallographic structures are available. The model was constructed with an alignment of D1 and D2 sequences with the L and M subunits of the bacterial reaction center, respectively, and by using as a scaffold the structurally conserved regions (SCRs) from bacterial templates. The structurally variant regions were built using a novel sequence-specific approach of searching for the best-matched protein segments in the Protein Data Bank with the "basic local alignment search tool" (Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ, 1990, J Mol Biol 215:403-410), and imposing the matching conformational preference on the corresponding D1 and D2 regions. The structure thus obtained was refined by energy minimization. The modeled D1 and D2 proteins contain five transmembrane alpha-helices each, with cofactors (4 chlorophylls, 2 pheophytins, 2 plastoquinones, and a non-heme iron) essential for PSII primary photochemistry embedded in them. A beta-carotene, considered important for PSII photoprotection, was also included in the model. Four different possible conformations of the primary electron donor P680 chlorophylls were proposed, one based on the homology with the bacterial template and the other three on existing experimental suggestions in literature. The P680 conformation based on homology was preferred because it has the lowest energy. Redox active tyrosine residues important for P680+ reduction as well as residues important for PSII cofactor binding were analyzed. Residues involved in interprotein interactions in the model were also identified. Herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) was also modeled in the plastoquinone QB binding niche using the structural information available from a DCMU-binding bacterial reaction center. A bicarbonate anion, known to play a role in PSII, but not in anoxygenic photosynthetic bacteria, was modeled in the non-heme iron site, providing a bidentate ligand to the iron. By modifying the previous hypothesis of Blubaugh and Govindjee (1988, Photosyn Res 19:85-128), we modeled a second bicarbonate and a water molecule in the QB site and we proposed a hypothesis to explain the mechanism of QB protonation mediated by bicarbonate and water. The bicarbonate, stabilized by D1-R257, donates a proton to QB2- through the intermediate of D1-H252; and a water molecule donates another proton to QB2-. Based on the discovery of a "water transport channel" in the bacterial reaction center, an analogous channel for transporting water and bicarbonate is proposed in our PSII model. The putative channel appears to be primarily positively charged near QB and the non-heme iron, in contrast to the polarity distribution in the bacterial water transport channel. The constructed model has been found to be consistent with most existing data.
Collapse
Affiliation(s)
- J Xiong
- Department of Plant Biology, University of Illinois at Urbana-Champaign 61801, USA
| | | |
Collapse
|
16
|
Mulkidjanian AY, Cherepanov DA, Haumann M, Junge W. Photosystem II of green plants: topology of core pigments and redox cofactors as inferred from electrochromic difference spectra. Biochemistry 1996; 35:3093-107. [PMID: 8608150 DOI: 10.1021/bi9513057] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Three electrochromic difference spectra induced by the deposition of (1) a negative charge on the primary quinone acceptor, Q(A), (2) a positive charge on (or near) Tyr161 of the D1 subunit (Y(Z)), and (3) a positive charge on the manganese cluster were determined at room temperature in photosystem II (PSII) core particles from pea. They were deconvoluted into Gaussian components by Powell's numerical optimization procedure. All three spectra were fitted by four components, which we assigned to the Q(y) absorption bands of two chlorophyll a molecules of the primary donor P, the accessory chlorophyll a, and the pheophytin a molecules on the D1 subunit. On the basis of the electrochromic properties of chlorins and our data, we suggest an arrangement of pigments and redox cofactors in PSII that differs from current structural models, which have been shaped like the reaction centers (RC) of purple bacteria. Our model is compatible with sequence data, with the spectroscopic and electrochemical properties of chlorophyll a and pheophytin a, and with the extremely positive redox potential of water oxidation. We conclude the following: (1) P is formed from two orthogonally oriented chlorophyll a molecules that peak at 681 and 677 nm. (2) The accessory chlorophyll a on D1 is oriented perpendicular to the membrane, with ring V pointing to Q(A). It is presumably attached to His118 of D1. (3) The mutual arrangement of pheophytin a on the D1 subunit and Q(A) differs from that of their counterparts in bacterial RC. (4) The manganese cluster is located out of the axis that is formed by Y(Z) (Tyr161 of D1), P, and Y(D) (Tyr161 of D2).
Collapse
Affiliation(s)
- A Y Mulkidjanian
- Abteilung Biophysik, Fachbereich Biologie/Chemie, Universität Osnabrück, Germany
| | | | | | | |
Collapse
|
17
|
Bosch MK, Proskuryakov II, Gast P, Hoff AJ. Time-Resolved EPR Study of the Primary Donor Triplet in D1-D2-cyt b559 Complexes of Photosystem II: Temperature Dependence of Spin−Lattice Relaxation. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp951334r] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Martin K. Bosch
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Ivan I. Proskuryakov
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Peter Gast
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| | - Arnold J. Hoff
- Department of Biophysics, Huygens Laboratory, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Institute of Soil Science and Photosynthesis, Russian Academy of Sciences, 142292 Pushchino, Moscow Region, Russia
| |
Collapse
|
18
|
|
19
|
Fiege R, Schreiber U, Renger G, Lubitz W, Shuvalov VA. Study of heme Fe(III) ligated by OH- in cytochrome b-559 and its low temperature photochemistry in intact chloroplasts. FEBS Lett 1995; 377:325-9. [PMID: 8549748 DOI: 10.1016/0014-5793(95)01363-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
EPR properties of Cyt b-559 have been investigated in intact chloroplasts that are functionally competent in O2 evolution and in CO2 fixation. After chemical oxidation of Cyt b-559 by 10 mM 2,3-dicyano, 4,5-dichloro-p-benzoquinone (DDQ) the major part of Cyt b-559 is found to be present in the high spin Fe(III) form. Only a small fraction of low spin heme Fe(III) (less than 5%) was formed by chemical or light-induced oxidation. This fraction increased during aging of intact chloroplasts. A comparison with the EPR signal of Fe(III) in myoglobin (Mb) reveals that the structure of the high spin signal in intact chloroplasts is indicative for the presence of an axial OH- ligand at the heme Fe(III). This type of ligation comprised a considerable part (approximately 40%) of the total Cyt b-559 content. Removal of the Mn-cluster caused a change of the EPR parameters of OH- ligation. When in intact chloroplasts the heme Fe is chemically oxidized to Fe(III) ligated by OH-, this OH- ligation disappeared after a subsequent illumination at 80K by red light. Upon illumination at 140K this disappearance was accompanied by the formation of a high spin Fe(III) that is not ligated by OH-. These results are discussed in terms of removal of OH- from Fe(III) caused by structural changes or photooxidation at a complex of Cyt b-559 that could possibly also comprise the Mn-cluster. This photooxidation is assumed to be accompanied by the formation of a bound OH. radical. The possibility is discussed that this process is related to photosynthetic water oxidation.
Collapse
Affiliation(s)
- R Fiege
- Max-Volmer-Institut für Biophysikalische und Physikalische Chemie, Technische Universität Berlin, Germany
| | | | | | | | | |
Collapse
|
20
|
Shuvalov VA, Fiege R, Schreiber U, Lendzian F, Lubitz W. EPR study of cytochrome in the D1D2 Cyt b-559 complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1995. [DOI: 10.1016/0005-2728(94)00168-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
21
|
van der Vos R, Hoff AJ. Optically-detected magnetic field effects on the Dl-D2-cyt b-559 complex of Photosystem II. Temperature dependence of kinetics and structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1995. [DOI: 10.1016/0005-2728(94)00167-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
22
|
Kaminskaya OP, Shuvalov VA. Irreversible light-induced formation of P680+ and reduced cytochrome b559 in the D1-D2-Cyt b-559 complex at low temperature. FEBS Lett 1994; 355:301-4. [PMID: 7988693 DOI: 10.1016/0014-5793(94)01122-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cytochrome b559 in D1-D2-Cyt b-559 complexes from spinach can be photoreduced in the presence of DBMIB at a temperature of 180-240 K upon continuous illumination. The reduction of Cyt b-559 is accompanied by oxidation of P680. At 240 K recombination of P680+ and reduced Cyt b-559 is complete in several seconds. At 220 K and below, the state P680+Cyt b-559red can be trapped for a long time. This indicates that the photoreduced heme is incapable of electron transfer to P680+ at 220 K and below. On the other hand, the chemically reduced heme of Cyt b-559 is oxidized by P680+ at 77 K. These results are consistent with the presence of two kinds of Cyt b-559 hemes in D1-D2-Cyt b-559 complexes which participate in different ways in the photochemical reactions.
Collapse
Affiliation(s)
- O P Kaminskaya
- Institute of Soil Sciences and Photosynthesis, Russian Academy of Sciences, Pushchino, Moscow region
| | | |
Collapse
|
23
|
Shuvalov VA. Composition and function of cytochrome b559 in reaction centers of photosystem II of green plants. J Bioenerg Biomembr 1994; 26:619-26. [PMID: 7721723 DOI: 10.1007/bf00831536] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A review of a recent study of the spectral and thermodynamic properties of cytochrome b559 as well as of the electron transfer between b559 and photosystem II reaction center cofactors in isolated D1/D2/cytochrome b559 complex RC-2 is presented. Attention is paid to the existence of intermediary-potential (IP, +150 mV) and extra-low-potential (XLP, -45 mV) hemes located close to the acceptor (quinone) and donor (P680) sides of the reaction center cofactors, respectively. These hemes found in isolated RC-2 probably correspond to the high-potential and low-potential hemes in chloroplasts, respectively. The above location of the hemes is believed to allow the photoreduction of the XLP heme and photooxidation of the IP heme. The electron transfer between the two hemes is discussed in terms of the cyclic electron flow and possible involvement in water splitting.
Collapse
Affiliation(s)
- V A Shuvalov
- Belozersky Institute of Physical Chemical Biology, Moscow State University, Russia
| |
Collapse
|
24
|
Ananyev G, Renger G, Wacker U, Klimov V. The photoproduction of superoxide radicals and the superoxide dismutase activity of Photosystem II. The possible involvement of cytochrome b559. PHOTOSYNTHESIS RESEARCH 1994; 41:327-38. [PMID: 24310115 DOI: 10.1007/bf00019410] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/1993] [Accepted: 04/11/1994] [Indexed: 05/22/2023]
Abstract
In the present study the light induced formation of superoxide and intrinsic superoxide dismutase (SOD) activity in PS II membrane fragments and D1/D2/Cytb559-complexes from spinach have been analyzed by the use of ferricytochrome c (cyt c(III)) reduction and xanthine/xanthine oxidase as assay systems. The following results were obtained: 1.) Photoreduction of Cyt c (III) by PS II membrane fragments is induced by addition of sodium azide, tetracyane ethylene (TCNE) or carbonylcyanide-p-trifluoromethoxy-phenylhydrazone (FCCP) and after removal of the extrinsic polypeptides by a 1M CaCl2-treatment. This activity which is absent in control samples becomes completely inhibited by the addition of exogenous SOD. 2.) The TCNE induced cyt c(III) photoreduction by PS II membrane fragments was found to be characterized by a half maximal concentration of c1/2=10 μM TCNE. Simultaneously, TCNE inhibits the oxygen evolution rate of PS II membrane fragments with c1/2≈ 3 μM. 3.) The photoproduction of O2 (-) is coupled with H(+)-uptake. This effect is diminished by the addition of the O2 (-)-trap cyt c(III). 4.) D1/D2/Cytb559-complexes and PS II membrane fragments deprived of the extrinsic proteins and manganese exhibit no SOD-activity but are capable of producing O2 (-) in the light if a PS II electron donor is added.Based on these results the site(s) of light induced superoxide formation in PS II is (are) inferred to be located at the acceptor side. A part of the PS II donor side and Cyt b559 in its HP-form are proposed to provide an intrinsic superoxide dismutase (SOD) activity.
Collapse
Affiliation(s)
- G Ananyev
- Institut of Soil Science and Photosynthesis, Russian Academy of Sciences, Pushchino, Moskow Region, (Russia)
| | | | | | | |
Collapse
|
25
|
Energy transfer, charge separation and pigment arrangement in the reaction center of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1994. [DOI: 10.1016/0005-2728(94)90229-1] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
26
|
Allakhverdiev SI, Ahmed A, Tajmir-Riahi HA, Klimov VV, Carpentier R. Light-induced Fourier transform infrared spectrum of the cation radical P680+. FEBS Lett 1994; 339:151-4. [PMID: 8313965 DOI: 10.1016/0014-5793(94)80404-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The structure of the primary electron donor of photosystem II, P680, is still under debate. It is not decided if it is composed of a chlorophyll (Chl) monomer or dimer. In this study, Fourier transform infrared (FTIR) spectroscopy was used to analyze the changes in the vibration modes occurring upon photooxidation of P680 in a Mn-depleted PS II preparation. It is demonstrated that illumination of the above in the presence of artificial electron acceptors results in a light-minus-dark absorbance change typical of the formation of P680+. The light-minus-dark difference FTIR spectrum obtained under similar conditions is characterized by two negative peaks located at 1694 and 1652 or 1626 cm-1 that can be assigned to the 9-keto groups of the P680 Chl, the latter band being indicative of a strongly associated group. These vibrations are shifted to 1714 and 1676 cm-1, respectively, in the positive features of the difference spectrum attributed to P680+. The occurrence of two pairs of bands attributed to 9-keto groups is discussed in terms of P680 being formed of a Chl dimer.
Collapse
Affiliation(s)
- S I Allakhverdiev
- Centre de recherche en photobiophysique, Université du Québec à Trois-Rivières, Canada
| | | | | | | | | |
Collapse
|
27
|
Shuvalov VA, Schreiber U, Heber U. Spectral and thermodynamic properties of the two hemes of the D1D2cytochrome b-559 complex of spinach. FEBS Lett 1994; 337:226-30. [PMID: 8293804 DOI: 10.1016/0014-5793(94)80196-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In agreement with previous work [Shuvalov, Heber and Schreiber (1988) FEBS Lett. 258, 27-31] two hemes (low potential (LP) and extra low potential (XLP)) per two pheophytins were found in isolated D1D2Cyt b-559 complexes. Reductive and oxidative redox titrations demonstrate that the Em of the LP form is at about +150 mV. It is independent of pH between pH 7.2 and 9.4. The XLP heme is autoxidizable at pH 7.2 and displays, at this pH, an Em of -45 mV. Both the LP and XLP hemes show absorption peaks at 559 nm. They are proposed to have bis-histidine ligation of the heme iron. At pH 9.4, the XLP heme splits into two forms. One of them has an Em of +40 mV, and absorption peaks at 559 nm showing the bis-histidine ligation. The other displays an Em of -220 mV and the peak is shifted to 562 nm. This last form is proposed to be due to the incorporation of OH- which occupies the 6th coordination position of the heme Fe(III) at high pH. The pK value for the conversion of the XLP heme is close to 7.7. In a structure simulation of the alpha-helices of alpha- and beta-polypeptide, the beta-polypeptide, but not the alpha-polypeptide, reveals a distance between the histidine N and the heme Fe which permits stable N-Fe coordination. In the alpha-polypeptide, OH- can be incorporated between N and Fe. The functional role of the two hemes of cyt b-559 is briefly discussed with respect to water oxidation and cyclic electron transfer.
Collapse
Affiliation(s)
- V A Shuvalov
- Julius-von-Sachs Institute of Biosciences, University of Würzburg, Germany
| | | | | |
Collapse
|
28
|
Roelofs TA, Kwa SL, van Grondelle R, Dekker JP, Holzwarth AR. Primary processes and structure of the Photosystem II reaction center: II. Low-temperature picosecond fluorescence kinetics of a D1-D2-cyt-b-559 reaction center complex isolated by short Triton exposure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90137-5] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
29
|
Redox potentials of cytochrome b-559 in the D1/D2/cytochrome b-559 reaction centre of Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90149-a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
30
|
Franck F. On the formation of photosystem II chlorophyll—proteins after a short light flash in etiolated barley leaves, as monitored by in vivo fluorescence spectroscopy. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1993. [DOI: 10.1016/1011-1344(93)80038-b] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
31
|
Ghirardi M, Mahajan S, Sopory S, Edelman M, Mattoo A. Photosystem II reaction center particle from Spirodela stroma lamellae. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53328-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
32
|
Moskalenko AA, Barbato R, Giacometti GM. Investigation of the neighbour relationships between photosystem II polypeptides in the two types of isolated reaction centres (D1/D2/cytb559 and CP47/D1/D2/cyt b559 complexes). FEBS Lett 1992; 314:271-4. [PMID: 1468557 DOI: 10.1016/0014-5793(92)81487-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The nearest neighbour relationships within the D1/D2/cyt b559 complex (PSIIRC) and the CP47/D1/D2/cyt b559 complex (RC-CP47) were investigated by using different length bifunctional crosslinking agents. The crosslinking products were identified by immunoblotting with polyclonal antibodies and by two-dimensional gel electrophoresis. Seven products (CP47/D2, D1/D2/alpha, D1/D2, D2/alpha, D1/alpha, alpha/alpha, alpha/beta) have been revealed in both complexes. The crosslinking of both complexes does not increase their photostability. The photocrosslinking products (D1/alpha and D2/alpha) appeared under illumination of complexes with light of high intensity.
Collapse
Affiliation(s)
- A A Moskalenko
- Institute of Soil Science and Photosynthesis RAS, Pushchino, Russian Federation
| | | | | |
Collapse
|
33
|
van der Vos R, van Leeuwen PJ, Braun P, Hoff AJ. Analysis of the optical absorbance spectra of D1-D2-cytochrome b-559 complexes by absorbance-detected magnetic resonance. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1992. [DOI: 10.1016/0005-2728(92)90008-p] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
34
|
Ruffle SV, Donnelly D, Blundell TL, Nugent JH. A three-dimensional model of the Photosystem II reaction centre of Pisum sativum. PHOTOSYNTHESIS RESEARCH 1992; 34:287-300. [PMID: 24408780 DOI: 10.1007/bf00033446] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/1992] [Accepted: 07/03/1992] [Indexed: 05/12/2023]
Abstract
A three-dimensional model of the core proteins D1 and D2, including the cofactors, that form the Photosystem II reaction centre of pea (Pisum sativum), has been generated. This model was built with a rule-based computer modelling system using the information from the crystal structures of the photosynthetic reaction centres of Rhodopseudomonas viridis and Rhodobacter sphaeroides. An alignment of the primary sequences of twenty three D1, nine D2, eight bacterial L and eight bacterial M subunits predicts strong similarity between bacterial and higher plant reaction centres, especially in the transmembrane region where the cofactors responsible for electron transport are located. The sequence to be modelled was aligned to the bacterial structures using environment-dependent substitution tables to construct matrices, improving the alignment procedure. The ancestral relationship between the bacteria and higher plant sequences allowed both the L and M subunits to be used as structural templates as they were equally related to the higher plant polypeptides. The regions with the highest predicted structural homology were used as a framework for the construction of the structurally conserved regions. The structurally conserved region of the model shows strong similarity to the bacterial reaction centre in the transmembrane helices. The stromal and lumenal loops show greater sequence variation and are therefore predicted to be the structurally variable regions in the model. The key sidechain assignments and residues that may interact with cofactors are discussed.
Collapse
Affiliation(s)
- S V Ruffle
- Department of Biology, Darwin Building, University College, University of London, Gower Street, WC1 E 6BT, London, UK
| | | | | | | |
Collapse
|
35
|
Steady state spectroscopy at 6 K of the isolated photosystem II reaction centre: Analysis of the red absorption band. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1992. [DOI: 10.1016/1011-1344(92)87002-q] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
36
|
Kwa SL, Newell WR, van Grondelle R, Dekker JP. The reaction center of photosystem II studied with polarized fluorescence spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1992. [DOI: 10.1016/0005-2728(92)90027-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
37
|
Montoya G, Yruela I, Picorel R. Pigment stoichiometry of a newly isolated D1-D2-Cyt b559 complex from the higher plant Beta vulgaris L. FEBS Lett 1991; 283:255-8. [PMID: 2044763 DOI: 10.1016/0014-5793(91)80601-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Two D1-D2-Cyt b559 complexes with different pigment stoichiometry were isolated from the higher plant B. vulgaris. The procedures for isolating both complexes only differed in the washing time of the DEAE column with 50 mM Tris-HCl, pH 7.2, 0.05% Triton X-100 and 30 mM NaCl. When the column was washed until the eluate had an absorbance of 0.01 at 670 nm, the isolated D1-D2-Cyt b559 complex presented a pigment stoichiometry of 6 chlorophyll a, 2 beta-carotene, and 1 cytochrome b559 per 2 pheophytin a. In contrast, when the column was exhaustively washed until the eluate reached an absorbance of 0.005 at 670 nm, the complex had a stoichiometry of 4 chlorophyll a, 1 beta-carotene, and 1 cytochrome b559 per 2 pheophytin a. We think that the former stoichiometry corresponds to that of the native D1-D2-Cyt b559 complex. Moreover, both preparations showed 2 mol of pheophytin a per 1 mol of reaction center protein.
Collapse
Affiliation(s)
- G Montoya
- Estación Experimental Aula Dei, CSIC, Zaragoza, Spain
| | | | | |
Collapse
|
38
|
van Leeuwen PJ, Nieveen MC, van de Meent EJ, Dekker JP, van Gorkom HJ. Rapid and simple isolation of pure photosystem II core and reaction center particles from spinach. PHOTOSYNTHESIS RESEARCH 1991; 28:149-53. [PMID: 24414974 DOI: 10.1007/bf00054128] [Citation(s) in RCA: 123] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/1991] [Accepted: 07/12/1991] [Indexed: 05/22/2023]
Abstract
Pure and active oxygen-evolving PS II core particles containing 35 Chl per reaction center were isolated with 75% yield from spinach PS II membrane fragments by incubation with n-dodecyl-β-D-maltoside and a rapid one step anion-exchange separation. By Triton X-100 treatment on the column these particles could be converted with 55% yield to pure and active PS II reaction center particles, which contained 6 Chl per reaction center.
Collapse
Affiliation(s)
- P J van Leeuwen
- Department of Biophysics, Huygens laboratory of the State University, P.O. Box 9504, 2300 RA, Leiden
| | | | | | | | | |
Collapse
|
39
|
Tang D, Jankowiak R, Seibert M, Small GJ. Effects of detergent on the excited state structure and relaxation dynamics of the photosystem II reaction center: A high resolution hole burning study. PHOTOSYNTHESIS RESEARCH 1991; 27:19-29. [PMID: 24414442 DOI: 10.1007/bf00029973] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/1990] [Accepted: 08/24/1990] [Indexed: 06/03/2023]
Abstract
Low temperature (4.2 K) absorption and hole burned spectra are reported for a stabilized preparation (no excess detergent) of the photosystem II reaction center complex. The complex was studied in glasses to which detergent had and had not been added. Triton X-100 (but not dodecyl maltoside) detergent was found to significantly affect the absorption and persistent hole spectra and to disrupt energy transfer from the accessory chlorophyll a to the active pheophytin a. However, Triton X-100 does not significantly affect the transient hole spectrum and lifetime (1.9 ps at 4.2 K) of the primary donor state, P680(*). Data are presented which indicate that the disruptive effects of Triton X-100 are not due to extraction of pigments from the reaction center, leaving structural perturbations as the most plausible explanation. In the absence of detergent the high resolution persistent hole spectra yield an energy transfer decay time for the accessory Chl a QY-state at 1.6 K of 12 ps, which is about three orders of magnitude longer than the corresponding time for the bacterial RC. In the presence of Triton X-100 the Chl a QY-state decay time is increased by at least a factor of 50.
Collapse
Affiliation(s)
- D Tang
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, 50011, Ames, IA, USA
| | | | | | | |
Collapse
|
40
|
Time-resolved spectroscopy at 10 K of the Photosystem II reaction center; deconvolution of the red absorption band. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90045-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
41
|
Gounaris K, Chapman DJ, Booth P, Crystall B, Giorgi LB, Klug DR, Porter G, Barber J. Comparison of the D1/D2/cytochrome b559 reaction centre complex of photosystem two isolated by two different methods. FEBS Lett 1990; 265:88-92. [PMID: 2194834 DOI: 10.1016/0014-5793(90)80890-u] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Photosystem 2 reaction centre complexes prepared either by solubilisation with Triton X-100 and subsequent exchange into dodecyl maltoside or by a procedure involving a combination of dodecyl maltoside and LiClO4, were characterised in terms of chlorophyll a, pheophytin a, beta-carotene and cytochrome b559 content. Time-resolved chlorophyll fluorescence decay kinetics were measured using both types of complexes. Our data show that the isolated photosystem two reaction centre complex contain, for two pheophytin a molecules, close to six chlorophyll a, two beta-carotene and one cytochrome b559. No major differences were observed in the composition or the kinetic characteristics measured in the samples prepared by the different procedures. Time-resolved fluorescence measurements indicate that more than 94% of the chlorophyll a in both preparations is coupled to the reaction centre complex.
Collapse
Affiliation(s)
- K Gounaris
- Biochemistry Department, Imperial College, London, UK
| | | | | | | | | | | | | | | |
Collapse
|