51
|
A study of Photosystem II fluorescence emission in terms of the antenna chlorophyll-protein complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90018-b] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
52
|
Macpherson AN, Telfer A, Barber J, Truscott T. Direct detection of singlet oxygen from isolated Photosystem II reaction centres. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90201-p] [Citation(s) in RCA: 154] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
53
|
De Las Rivas J, Telfer A, Barber J. Two coupled β-carotene molecules protect P680 from photodamage in isolated Photosystem II reaction centres. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90097-y] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
54
|
Functional reconstitution of the primary quinone acceptor, QA, in the Photosystem II core complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1993. [DOI: 10.1016/0005-2728(93)90081-p] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
55
|
Yruela I, Alfonso M, Ortiz de Zarate I, Montoya G, Picorel R. Precise location of the Cu(II)-inhibitory binding site in higher plant and bacterial photosynthetic reaction centers as probed by light-induced absorption changes. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)53906-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
56
|
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
|
57
|
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]
|
58
|
De Las Rivas J, Crystall B, Booth PJ, Durrant JR, Ozer S, Porter G, Klug DR, Barber J. Long-lived primary radical pair state detected by time-resolved fluorescence and absorption spectroscopy in an isolated Photosystem two core. PHOTOSYNTHESIS RESEARCH 1992; 34:419-431. [PMID: 24408837 DOI: 10.1007/bf00029816] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/1992] [Accepted: 06/08/1992] [Indexed: 06/03/2023]
Abstract
A Photosystem two (PS II) core preparation containing the chlorophyll a binding proteins CP 47, CP 43, D1 and D2, and the non-chlorophyll binding cytochrome-b559 and 33 kDA polypeptides, has been isolated from PS II-enriched membranes of peas using the non-ionic detergent heptylthioglucopyranoside and elevated ionic strengths. The primary radical pair state, P680(+)Pheo(-), was studied by time-resolved absorption and fluorescence spectroscopy, under conditions where quinone reduction and water-splitting activities were inhibited. Charge recombination of the primary radical pair in PS II cores was found to have lifetimes of 17.5 ns measured by fluorescence and 21 ns measured by transient decay kinetics under anaerobic conditions. Transient absorption spectroscopy demonstrated that the activity of the particles, based on primary radical pair formation, was in excess of 70% (depending on the choice of kinetic model), while time-resolved fluorescence spectroscopy indicated that the particles were 91% active. These estimates of activity were further supported by steady-state measurements which quantified the amount of photoreducible pheophytin. It is concluded that the PS II core preparation we have isolated is ideal for studying primary radical pair formation and recombination as demonstrated by the correlation of our absorption and fluorescence transient data, which is the first of its kind to be reported in the literature for isolated PS II core complexes from higher plants.
Collapse
|
59
|
Debus RJ. The manganese and calcium ions of photosynthetic oxygen evolution. BIOCHIMICA ET BIOPHYSICA ACTA 1992; 1102:269-352. [PMID: 1390827 DOI: 10.1016/0005-2728(92)90133-m] [Citation(s) in RCA: 970] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- R J Debus
- Department of Biochemistry, University of California Riverside 92521-0129
| |
Collapse
|
60
|
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]
|
61
|
Maciy K, Renger G, Haag E, Voigt J. Light-induced degradation of PS II reaction centres analyzed by measurements of steady-state fluorescence spectra in D1/D2/cytochrome b-559 preparations from spinach. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1992. [DOI: 10.1016/0005-2728(92)90067-c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
62
|
|
63
|
Cleland RE, Rees D, Horton P. Light-induced fluorescence quenching and loss of photochemistry in chromatophores of photosynthetic purple bacteria. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1992. [DOI: 10.1016/1011-1344(92)85065-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
64
|
Tae GS, Cramer WA. Truncation of the COOH-terminal domain of the psbE gene product in Synechocystis sp. PCC 6803: requirements for photosystem II assembly and function. Biochemistry 1992; 31:4066-74. [PMID: 1567853 DOI: 10.1021/bi00131a024] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The COOH-terminal domain of the 80-residue cytochrome b559 alpha-subunit (psbE gene product) in Synechocystis sp. PCC 6803 was sequentially truncated in order to determine the minimum polypeptide length needed for function and assembly. A stop codon was introduced into the Arg-50, Arg-59, or Tyr-69 codons of the psbE gene, generating mutants truncated by 31, 22, and 12 residues, respectively. Removal of 12 residues caused a decrease of 20% in PSII function. Truncation of 22 or 31 residues caused a large decrease (60-85%) in the photoautotrophic growth rate, the rate of O2 evolution, and the amplitude of the 77 K 696-nm fluorescence, and a concomitant increase in the constant yield fraction (F0/Fmax) of the chlorophyll fluorescence. The level of residual activity in the Arg50-stop mutant was 10-20% of the wild type, which was reflected in a similar low level of immunochemically detected D2 polypeptide. Quantitation of the PSII reaction center stoichiometry of the Arg50-stop mutant by analysis of [14C]DCMU binding also showed a 5-fold decrease (1:910 Chl in wild type and 1:5480 Chl in R50) in the PSII reaction center concentration. However, the KD value for DCMU in the residual 15% of the complexes to which it bound was approximately equal to that (25 nM) of the wild type. Northern blot analysis showed no decrease in the b559 psbE mRNA level. Chemical difference spectral analysis of heme content indicated that the level of native cytochrome b559 heme in the Arg50-stop mutant (1:640 Chl) was 80% that of wild type (1:510 Chl).(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- G S Tae
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907
| | | |
Collapse
|
65
|
De Las Rivas J, Andersson B, Barber J. Two sites of primary degradation of the D1-protein induced by acceptor or donor side photo-inhibition in photosystem II core complexes. FEBS Lett 1992; 301:246-52. [PMID: 1577160 DOI: 10.1016/0014-5793(92)80250-k] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Depending on experimental conditions we have found that photo-inhibitory treatment of photosystem II (PSII) core complexes, isolated from wheat, can generate two fragments of about 23-24 kDa that contain either the C-terminal or N-terminal regions of the D1-protein. A 24 kDa C-terminal fragment appears when the water splitting reaction is not functional and an electron acceptor is present. This 'donor'-side inhibition also generates an N-terminal fragment of about 10 kDa and is suggested to be due to the cleavage of a peptide bond in the region connecting transmembrane segments I and II of the D1-protein. In contrast, an N-terminal 23 kDa D1-protein fragment is detected when the water splitting reactions of the isolated complex are active, and occurs in the absence of an added electron acceptor. This 'acceptor'-side photo-inhibition also generates a C-terminal fragment of about 10 kDa.
Collapse
Affiliation(s)
- J De Las Rivas
- Biochemistry Department, Wolfson Laboratories, Imperial College of Science, Technology and Medicine, London, UK
| | | | | |
Collapse
|
66
|
Telfer A, De Las Rivas J, Barber J. β-Carotene within the isolated Photosystem II reaction centre: photooxidation and irreversible bleaching of this chromophore by oxidised P680. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1991. [DOI: 10.1016/s0005-2728(05)80125-2] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
67
|
Taneva S, Busheva M, Petkanchin I. Electric parameters of photosystem II particles — electric light scattering study. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1991. [DOI: 10.1016/1011-1344(91)80017-c] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
68
|
Preparation and characterisation of Photosystem II core particles with and without bound bicarbonate. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1991. [DOI: 10.1016/s0005-2728(05)80123-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
69
|
Booth PJ, Crystall B, Ahmad I, Barber J, Porter G, Klug DR. Observation of multiple radical pair states in photosystem 2 reaction centers. Biochemistry 1991; 30:7573-86. [PMID: 1854756 DOI: 10.1021/bi00244a029] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Charge recombination of the primary radical pair in D1/D2 reaction centers from photosystem 2 has been studied by time-resolved fluorescence and absorption spectroscopy. The kinetics of the primary radical pair are multiexponential and exhibit at least two lifetimes of 20 and 52 ns. In addition, a third lifetime of approximately 500 ps also appears to be present. These multiexponential charge-recombination kinetics reflect either different conformational states of D1/D2 reaction centers, with the different conformers exhibiting different radical pair lifetimes, or relaxations in the free energy of the radical pair state. Whichever model is invoked, the free energies of formation of the different radical pair states exhibit a linear temperature dependence from 100 to 220 K, indicating that they are dominated by entropy with negligible enthalpy contributions. These results are in agreement with previous determinations of the thermodynamics that govern primary charge separation in both D1/D2 reaction centers [Booth, P.J., Crystall, B., Giorgi, L. B., Barber, J., Klug, D.R., & Porter, G. (1990) Biochim. Biophys. Acta 1016, 141-152] and reaction centers of purple bacteria [Woodbury, N.W.T., & Parson, W.W. (1984) Biochim. Biophys. Acta 767, 345-361]. It is possible that these observations reflect structural changes that accompanying primary charge separation and assist in stabilization of the radical pair state thus optimizing the efficiency of primary electron transfer.
Collapse
Affiliation(s)
- P J Booth
- Photochemistry Research Group, Department of Biology, Imperial College, London, U.K
| | | | | | | | | | | |
Collapse
|
70
|
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
|
71
|
Chapman D, Vass I, Barber J. Secondary electron transfer reactions of the isolated Photosystem II reaction centre after reconstitution with plastoquinone-9 and diacylglycerolipids. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1991. [DOI: 10.1016/s0005-2728(05)80153-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
72
|
Newell W, Amerongen HV, Barber J, van Grondelle R. Spectroscopic characterisation of the reaction centre of photosystem II using polarised light: Evidence for β-carotene excitons in PS II reaction centres. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1991. [DOI: 10.1016/s0005-2728(05)80106-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
73
|
Nagatsuka T, Fukuhara S, Akabori K, Toyoshima Y. Disintegration and reconstitution of Photosystem II reaction center core complex. II. Possible involvement of low-molecular-mass proteins in the functioning of QA in the PS II reaction center. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1991. [DOI: 10.1016/s0005-2728(05)80105-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
74
|
Barber J, Melis A. Quantum efficiency for the photoaccumulation of reduced pheophytin in Photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90159-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
75
|
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]
|
76
|
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
|
77
|
Durrant J, Giorgi L, Barber J, Klug D, Porter G. Characterisation of triplet states in isolated Photosystem II reaction centres: Oxygen quenching as a mechanism for photodamage. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90148-w] [Citation(s) in RCA: 117] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
78
|
Spectral resolution of more than one chlorophyll electron donor in the isolated Photosystem II reaction centre complex. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90145-t] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
79
|
Millisecond time-resolved EPR of the spin-polarised triplet in the isolated Photosystem II reaction centre. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90064-b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
80
|
Thermodynamic properties of D1/D2/cytochrome b-559 reaction centres investigated by time-resolved fluorescence measurements. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90053-7] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
81
|
Satoh K, Hansson Ö, Mathis P. Charge recombination between stabilized P-680+ and reduced cytochrome b-559 in quinone-reconstituted PS II reaction center. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90014-u] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
82
|
Nabedryk E, Andrianambinintsoa S, Berger G, Leonhard M, Mäntele W, Breton J. Characterization of bonding interactions of the intermediary electron acceptor in the reaction center of Photosystem II by FTIR spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1990. [DOI: 10.1016/0005-2728(90)90005-o] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
83
|
Hansson O, Wydrzynski T. Current perceptions of Photosystem II. PHOTOSYNTHESIS RESEARCH 1990; 23:131-162. [PMID: 24421057 DOI: 10.1007/bf00035006] [Citation(s) in RCA: 134] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/1989] [Accepted: 06/05/1989] [Indexed: 06/03/2023]
Abstract
In the last few years our knowledge of the structure and function of Photosystem II in oxygen-evolving organisms has increased significantly. The biochemical isolation and characterization of essential protein components and the comparative analysis from purple photosynthetic bacteria (Deisenhofer, Epp, Miki, Huber and Michel (1984) J Mol Biol 180: 385-398) have led to a more concise picture of Photosystem II organization. Thus, it is now generally accepted that the so-called D1 and D2 intrinsic proteins bind the primary reactants and the reducing-side components. Simultaneously, the nature and reaction kinetics of the major electron transfer components have been further clarified. For example, the radicals giving rise to the different forms of EPR Signal II have recently been assigned to oxidized tyrosine residues on the D1 and D2 proteins, while the so-called Q400 component has been assigned to the ferric form of the acceptor-side iron. The primary charge-separation has been meaured to take place in about 3 ps. However, despite all recent major efforts, the location of the manganese ions and the water-oxidation mechanism still remain largely unknown. Other topics which lately have received much attention include the organization of Photosystem II in the thylakoid membrane and the role of lipids and ionic cofactors like bicarbonate, calcium and chloride. This article attempts to give an overall update in this rapidly expanding field.
Collapse
Affiliation(s)
- O Hansson
- Department of Biochemistry and Biophysics, Chalmers University of Technology, S-412 96, Göteborg, Sweden
| | | |
Collapse
|
84
|
Vass I, Chapman DJ, Barber J. Thermoluminescence properties of the isolated photosystem two reaction centre. PHOTOSYNTHESIS RESEARCH 1989; 22:295-301. [PMID: 24424818 DOI: 10.1007/bf00048307] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/1989] [Accepted: 06/22/1989] [Indexed: 06/03/2023]
Abstract
Formation of thermoluminescence signals is characteristics of energy- and charge storage in Photosystem II. In isolated D1/D2/cytochrome b-559 Photosystem II reaction centre preparation four thermoluminescence components were found. These appear at -180 (Z band), between -80 and -50 (Zv band), at -30 and at +35°C. The Z band arises from pigment molecules but not correlated with photosynthetic activity. The Zv and -30°C bands arise from the recombination of charge pairs stabilized in the Photosystem II reaction centre complex. The +35°C band probably corresponds to the artefact glow peak resulting from a pigment-protein-detergent interaction in subchloroplast preparations (Rózsa Zs, Droppa M and Horváth G (1989) Biochim Biophys Acta 973, 350-353).
Collapse
Affiliation(s)
- I Vass
- Institute of Plant Physiology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, H-6701, Szeged, Hungary
| | | | | |
Collapse
|
85
|
Gounaris K, Chapman DJ, Barber J. Isolation and characterisation of a Dl/D2/cytochrome b-559 complex from Synechocystis 6803. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1989. [DOI: 10.1016/s0005-2728(89)80435-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
86
|
Giardi MT, Marder JB, Barber J. Herbicide binding to the isolated Photosystem II reaction centre. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1988. [DOI: 10.1016/0005-2728(88)90120-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|