1
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Biswas S, Niedzwiedzki DM, Pakrasi HB. Introduction of cysteine-mediated quenching in the CP43 protein of photosystem II builds resilience to high-light stress in a cyanobacterium. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148580. [PMID: 35654167 DOI: 10.1016/j.bbabio.2022.148580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Revised: 05/16/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Photosystem (PS) II is prone to photodamage both as a direct consequence of light, and indirectly by producing reactive oxygen species. Engineering high-light tolerance in cyanobacteria with minimal impact on PSII function is desirable in synthetic biology. IsiA, a CP43 homolog found exclusively in cyanobacteria, can dissipate excess light energy. We have recently determined that the sole cysteine residue of IsiA in Synechocystis sp. PCC 6803 has a critical role in non-photochemical quenching. Similar cysteine-mediated energy quenching has also been observed in green‑sulfur bacteria. Sequence analysis of IsiA and CP43 aligns cysteine 260 of IsiA with valine 277 of CP43 in Synechocystis sp. PCC 6803. In the current study, we explore the impact of replacing valine 277 of CP43 to a cysteine on growth, PSII activity and high-light tolerance. Our results imply a decline in the PSII output for the mutant (CP43V277C) presumably due to the dissipation of absorbed light energy by cysteine. Spectroscopic analysis of isolated PSII from this mutant strain also suggests a delayed transfer of excitation energy from CP43-associated chlorophyll a to PSII reaction center. The mutation makes the PSII high-light tolerant and provides a small advantage in growth under high-light conditions. This previously unexplored strategy to engineer high-light tolerance could be a step further towards developing cyanobacterial cells as biofactories.
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Affiliation(s)
- Sandeep Biswas
- Department of Biology, Washington University, St. Louis, MO 63130, USA.
| | - Dariusz M Niedzwiedzki
- Center for Solar Energy and Energy Storage, Washington University, St. Louis, MO 63130, USA; Department of Energy, Environmental & Chemical Engineering, Washington University, St. Louis, MO 63130, USA.
| | - Himadri B Pakrasi
- Department of Biology, Washington University, St. Louis, MO 63130, USA.
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2
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Sirohiwal A, Neese F, Pantazis DA. Chlorophyll excitation energies and structural stability of the CP47 antenna of photosystem II: a case study in the first-principles simulation of light-harvesting complexes. Chem Sci 2021; 12:4463-4476. [PMID: 34163712 PMCID: PMC8179452 DOI: 10.1039/d0sc06616h] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Natural photosynthesis relies on light harvesting and excitation energy transfer by specialized pigment-protein complexes. Their structure and the electronic properties of the embedded chromophores define the mechanisms of energy transfer. An important example of a pigment-protein complex is CP47, one of the integral antennae of the oxygen-evolving photosystem II (PSII) that is responsible for efficient excitation energy transfer to the PSII reaction center. The charge-transfer excitation induced among coupled reaction center chromophores resolves into charge separation that initiates the electron transfer cascade driving oxygenic photosynthesis. Mapping the distribution of site energies among the 16 chlorophyll molecules of CP47 is essential for understanding excitation energy transfer and overall antenna function. In this work, we demonstrate a multiscale quantum mechanics/molecular mechanics (QM/MM) approach utilizing full time-dependent density functional theory with modern range-separated functionals to compute for the first time the excitation energies of all CP47 chlorophylls in a complete membrane-embedded cyanobacterial PSII dimer. The results quantify the electrostatic effect of the protein on the site energies of CP47 chlorophylls, providing a high-level quantum chemical excitation profile of CP47 within a complete computational model of "near-native" cyanobacterial PSII. The ranking of site energies and the identity of the most red-shifted chlorophylls (B3, followed by B1) differ from previous hypotheses in the literature and provide an alternative basis for evaluating past approaches and semiempirically fitted sets. Given that a lot of experimental studies on CP47 and other light-harvesting complexes utilize extracted samples, we employ molecular dynamics simulations of isolated CP47 to identify which parts of the polypeptide are most destabilized and which pigments are most perturbed when the antenna complex is extracted from PSII. We demonstrate that large parts of the isolated complex rapidly refold to non-native conformations and that certain pigments (such as chlorophyll B1 and β-carotene h1) are so destabilized that they are probably lost upon extraction of CP47 from PSII. The results suggest that the properties of isolated CP47 are not representative of the native complexed antenna. The insights obtained from CP47 are generalizable, with important implications for the information content of experimental studies on biological light-harvesting antenna systems.
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Affiliation(s)
- Abhishek Sirohiwal
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany.,Fakultät für Chemie und Biochemie, Ruhr-Universität Bochum 44780 Bochum Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Dimitrios A Pantazis
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
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3
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Reimers JR, Rätsep M, Freiberg A. Asymmetry in the Q y Fluorescence and Absorption Spectra of Chlorophyll a Pertaining to Exciton Dynamics. Front Chem 2020; 8:588289. [PMID: 33344415 PMCID: PMC7738624 DOI: 10.3389/fchem.2020.588289] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/26/2020] [Indexed: 11/13/2022] Open
Abstract
Significant asymmetry found between the high-resolution Qy emission and absorption spectra of chlorophyll-a is herein explained, providing basic information needed to understand photosynthetic exciton transport and photochemical reactions. The Qy spectral asymmetry in chlorophyll has previously been masked by interference in absorption from the nearby Qx transition, but this effect has recently been removed using extensive quantum spectral simulations or else by analytical inversion of absorption and magnetic circular dichroism data, allowing high-resolution absorption information to be accurately determined from fluorescence-excitation spectra. To compliment this, here, we measure and thoroughly analyze the high-resolution differential fluorescence line narrowing spectra of chlorophyll-a in trimethylamine and in 1-propanol. The results show that vibrational frequencies often change little between absorption and emission, yet large changes in line intensities are found, this effect also being strongly solvent dependent. Among other effects, the analysis in terms of four basic patterns of Duschinsky-rotation matrix elements, obtained using CAM-B3LYP calculations, predicts that a chlorophyll-a molecule excited into a specific vibrational level, may, without phase loss or energy relaxation, reemit the light over a spectral bandwidth exceeding 1,000 cm−1 (0.13 eV) to influence exciton-transport dynamics.
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Affiliation(s)
- Jeffrey R Reimers
- School of Chemistry, The University of Sydney, Sydney, NSW, Australia
| | - Margus Rätsep
- Institute of Physics, University of Tartu, Tartu, Estonia
| | - Arvi Freiberg
- Institute of Physics, University of Tartu, Tartu, Estonia.,Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
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4
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Pieper J, Artene P, Rätsep M, Pajusalu M, Freiberg A. Evaluation of Electron–Phonon Coupling and Spectral Densities of Pigment–Protein Complexes by Line-Narrowed Optical Spectroscopy. J Phys Chem B 2018; 122:9289-9301. [DOI: 10.1021/acs.jpcb.8b05220] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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5
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Pieper J, Rätsep M, Golub M, Schmitt FJ, Artene P, Eckert HJ. Excitation energy transfer in phycobiliproteins of the cyanobacterium Acaryochloris marina investigated by spectral hole burning. PHOTOSYNTHESIS RESEARCH 2017; 133:225-234. [PMID: 28560566 DOI: 10.1007/s11120-017-0396-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 05/06/2017] [Indexed: 06/07/2023]
Abstract
The cyanobacterium Acaryochloris marina developed two types of antenna complexes, which contain chlorophyll-d (Chl d) and phycocyanobilin (PCB) as light-harvesting pigment molecules, respectively. The latter membrane-extrinsic complexes are denoted as phycobiliproteins (PBPs). Spectral hole burning was employed to study excitation energy transfer and electron-phonon coupling in PBPs. The data reveal a rich spectral substructure with a total of four low-energy electronic states whose absorption bands peak at 633, 644, 654, and at about 673 nm. The electronic states at ~633 and 644 nm can be tentatively attributed to phycocyanin (PC) and allophycocyanin (APC), respectively. The remaining low-energy electronic states including the terminal emitter at 673 nm may be associated with different isoforms of PC, APC, or the linker protein. Furthermore, the hole burning data reveal a large number of excited state vibrational frequencies, which are characteristic for the chromophore PCB. In summary, the results are in good agreement with the low-energy level structure of PBPs and electron-phonon coupling parameters reported by Gryliuk et al. (BBA 1837:1490-1499, 2014) based on difference fluorescence line-narrowing experiments.
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Affiliation(s)
- Jörg Pieper
- Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411, Tartu, Estonia.
| | - Margus Rätsep
- Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411, Tartu, Estonia
| | - Maksym Golub
- Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411, Tartu, Estonia
| | - Franz-Josef Schmitt
- Max-Volmer-Laboratories for Biophysical Chemistry, Technical University Berlin, Berlin, Germany
| | - Petrica Artene
- Institute of Physics, University of Tartu, W. Ostwaldi 1, 50411, Tartu, Estonia
| | - Hann-Jörg Eckert
- Max-Volmer-Laboratories for Biophysical Chemistry, Technical University Berlin, Berlin, Germany
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6
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Jassas M, Reinot T, Kell A, Jankowiak R. Toward an Understanding of the Excitonic Structure of the CP47 Antenna Protein Complex of Photosystem II Revealed via Circularly Polarized Luminescence. J Phys Chem B 2017; 121:4364-4378. [PMID: 28394609 DOI: 10.1021/acs.jpcb.7b00362] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Identification of the lowest energy pigments in the photosynthetic CP47 antenna protein complex of Photosystem II (PSII) is essential for understanding its excitonic structure, as well as excitation energy pathways in the PSII core complex. Unfortunately, there is no consensus concerning the nature of the low-energy state(s), nor chlorophyll (Chl) site energies in this important photosynthetic antenna. Although we raised concerns regarding the estimations of Chl site energies obtained from modeling studies of various types of CP47 optical spectra [Reinot, T; et al., Anal. Chem. Insights 2016, 11, 35-48] recent new assignments imposed by the shape of the circularly polarized luminescence (CPL) spectrum [Hall, J.; et al., Biochim. Biophys. Acta 2016, 1857, 1580-1593] necessitate our comments. We demonstrate that other combinations of low-energy Chls provide equally good or improved simultaneous fits of various optical spectra (absorption, emission, CPL, circular dichroism, and nonresonant hole-burned spectra), but more importantly, we expose the heterogeneous nature of the recently studied complexes and argue that the published composite nature of the CPL (contributed to by CPL685, CPL691, and CPL695) does not represent an intact CP47 protein. A positive CPL695 is extracted for the intact protein, which, when simultaneously fitted with multiple other optical spectra, provides new information on the excitonic structure of intact and destabilized CP47 complexes and their lowest energy state(s).
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Affiliation(s)
- Mahboobe Jassas
- Department of Chemistry and ‡Department of Physics, Kansas State University , Manhattan, Kansas 66506, United States
| | - Tonu Reinot
- Department of Chemistry and ‡Department of Physics, Kansas State University , Manhattan, Kansas 66506, United States
| | - Adam Kell
- Department of Chemistry and ‡Department of Physics, Kansas State University , Manhattan, Kansas 66506, United States
| | - Ryszard Jankowiak
- Department of Chemistry and ‡Department of Physics, Kansas State University , Manhattan, Kansas 66506, United States
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7
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The lowest-energy chlorophyll of photosystem II is adjacent to the peripheral antenna: Emitting states of CP47 assigned via circularly polarized luminescence. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1580-1593. [PMID: 27342201 DOI: 10.1016/j.bbabio.2016.06.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/16/2016] [Accepted: 06/18/2016] [Indexed: 11/22/2022]
Abstract
The identification of low-energy chlorophyll pigments in photosystem II (PSII) is critical to our understanding of the kinetics and mechanism of this important enzyme. We report parallel circular dichroism (CD) and circularly polarized luminescence (CPL) measurements at liquid helium temperatures of the proximal antenna protein CP47. This assembly hosts the lowest-energy chlorophylls in PSII, responsible for the well-known "F695" fluorescence band of thylakoids and PSII core complexes. Our new spectra enable a clear identification of the lowest-energy exciton state of CP47. This state exhibits a small but measurable excitonic delocalization, as predicated by its CD and CPL. Using structure-based simulations incorporating the new spectra, we propose a revised set of site energies for the 16 chlorophylls of CP47. The significant difference from previous analyses is that the lowest-energy pigment is assigned as Chl 612 (alternately numbered Chl 11). The new assignment is readily reconciled with the large number of experimental observations in the literature, while the most common previous assignment for the lowest energy pigment, Chl 627(29), is shown to be inconsistent with CD and CPL results. Chl 612(11) is near the peripheral light-harvesting system in higher plants, in a lumen-exposed region of the thylakoid membrane. The low-energy pigment is also near a recently proposed binding site of the PsbS protein. This result consequently has significant implications for our understanding of the kinetics and regulation of energy transfer in PSII.
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8
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Reinot T, Chen J, Kell A, Jassas M, Robben KC, Zazubovich V, Jankowiak R. On the Conflicting Estimations of Pigment Site Energies in Photosynthetic Complexes: A Case Study of the CP47 Complex. ANALYTICAL CHEMISTRY INSIGHTS 2016; 11:35-48. [PMID: 27279733 PMCID: PMC4892206 DOI: 10.4137/aci.s32151] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 04/10/2016] [Accepted: 04/26/2016] [Indexed: 01/14/2023]
Abstract
We focus on problems with elucidation of site energies
(E0n) for photosynthetic complexes (PSCs) in order to raise some genuine concern regarding the conflicting estimations propagating in the literature. As an example, we provide a stern assessment of the site energies extracted from fits to optical spectra of the widely studied CP47 antenna complex of photosystem II from spinach, though many general comments apply to other PSCs as well. Correct values of
E0n for chlorophyll (Chl) a in CP47 are essential for understanding its excitonic structure, population dynamics, and excitation energy pathway(s). To demonstrate this, we present a case study where simultaneous fits of multiple spectra (absorption, emission, circular dichroism, and nonresonant hole-burned spectra) show that several sets of parameters can fit the spectra very well. Importantly, we show that variable emission maxima (690–695 nm) and sample-dependent bleaching in nonresonant hole-burning spectra reported in literature could be explained, assuming that many previously studied CP47 samples were a mixture of intact and destabilized proteins. It appears that the destabilized subpopulation of CP47 complexes could feature a weakened hydrogen bond between the 131-keto group of Chl29 and the PsbH protein subunit, though other possibilities cannot be entirely excluded, as discussed in this work. Possible implications of our findings are briefly discussed.
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Affiliation(s)
- Tonu Reinot
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Jinhai Chen
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Adam Kell
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Mahboobe Jassas
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | - Kevin C Robben
- Department of Chemistry, Kansas State University, Manhattan, KS, USA
| | | | - Ryszard Jankowiak
- Department of Chemistry, Kansas State University, Manhattan, KS, USA.; Department of Physics, Kansas State University, Manhattan, KS, USA
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9
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Chen J, Kell A, Acharya K, Kupitz C, Fromme P, Jankowiak R. Critical assessment of the emission spectra of various photosystem II core complexes. PHOTOSYNTHESIS RESEARCH 2015; 124:253-265. [PMID: 25832780 DOI: 10.1007/s11120-015-0128-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 03/23/2015] [Indexed: 06/04/2023]
Abstract
We evaluate low-temperature (low-T) emission spectra of photosystem II core complexes (PSII-cc) previously reported in the literature, which are compared with emission spectra of PSII-cc obtained in this work from spinach and for dissolved PSII crystals from Thermosynechococcus (T.) elongatus. This new spectral dataset is used to interpret data published on membrane PSII (PSII-m) fragments from spinach and Chlamydomonas reinhardtii, as well as PSII-cc from T. vulcanus and intentionally damaged PSII-cc from spinach. This study offers new insight into the assignment of emission spectra reported on PSII-cc from different organisms. Previously reported spectra are also compared with data obtained at different saturation levels of the lowest energy state(s) of spinach and T. elongatus PSII-cc via hole burning in order to provide more insight into emission from bleached and/or photodamaged complexes. We show that typical low-T emission spectra of PSII-cc (with closed RCs), in addition to the 695 nm fluorescence band assigned to the intact CP47 complex (Reppert et al. J Phys Chem B 114:11884-11898, 2010), can be contributed to by several emission bands, depending on sample quality. Possible contributions include (i) a band near 690-691 nm that is largely reversible upon temperature annealing, proving that the band originates from CP47 with a bleached low-energy state near 693 nm (Neupane et al. J Am Chem Soc 132:4214-4229, 2010; Reppert et al. J Phys Chem B 114:11884-11898, 2010); (ii) CP43 emission at 683.3 nm (not at 685 nm, i.e., the F685 band, as reported in the literature) (Dang et al. J Phys Chem B 112:9921-9933, 2008; Reppert et al. J Phys Chem B 112:9934-9947, 2008); (iii) trap emission from destabilized CP47 complexes near 691 nm (FT1) and 685 nm (FT2) (Neupane et al. J Am Chem Soc 132:4214-4229, 2010); and (iv) emission from the RC pigments near 686-687 nm. We suggest that recently reported emission of single PSII-cc complexes from T. elongatus may not represent intact complexes, while those obtained for T. elongatus presented in this work most likely represent intact PSII-cc, since they are nearly indistinguishable from emission spectra obtained for various PSII-m fragments.
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Affiliation(s)
- Jinhai Chen
- Department of Chemistry, Kansas State University, Manhattan, KS, 66506, USA
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10
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Excitation energy transfer and electron-vibrational coupling in phycobiliproteins of the cyanobacterium Acaryochloris marina investigated by site-selective spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:1490-9. [PMID: 24560813 DOI: 10.1016/j.bbabio.2014.02.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 01/26/2014] [Accepted: 02/12/2014] [Indexed: 10/25/2022]
Abstract
In adaption to its specific environmental conditions, the cyanobacterium Acaryochloris marina developed two different types of light-harvesting complexes: chlorophyll-d-containing membrane-intrinsic complexes and phycocyanobilin (PCB) - containing phycobiliprotein (PBP) complexes. The latter complexes are believed to form a rod-shaped structure comprising three homo-hexamers of phycocyanin (PC), one hetero-hexamer of phycocyanin and allophycocyanin (APC) and probably a linker protein connecting the PBPs to the reaction centre. Excitation energy transfer and electron-vibrational coupling in PBPs have been investigated by selectively excited fluorescence spectra. The data reveal a rich spectral substructure with a total of five low-energy electronic states with fluorescence bands at 635nm, 645nm, 654nm, 659nm and a terminal emitter at about 673 nm. The electronic states at ~635 and 645 nm are tentatively attributed to PC and APC, respectively, while an apparent heterogeneity among PC subunits may also play a role. The other fluorescence bands may be associated with three different isoforms of the linker protein. Furthermore, a large number of vibrational features can be identified for each electronic state with intense phonon sidebands peaking at about 31 to 37cm⁻¹, which are among the highest phonon frequencies observed for photosynthetic antenna complexes. The corresponding Huang-Rhys factors S fall in the range between 0.98 (terminal emitter), 1.15 (APC), and 1.42 (PC). Two characteristic vibronic lines at about 1580 and 1634cm⁻¹ appear to reflect CNH⁺ and CC stretching modes of the PCB chromophore, respectively. The exact phonon and vibrational frequencies vary with electronic state implying that the respective PCB chromophores are bound to different protein environments. This article is part of a special issue entitled: photosynthesis research for sustainability: keys to produce clean energy.
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11
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Ostroumov EE, Khan YR, Scholes GD, Govindjee. Photophysics of Photosynthetic Pigment-Protein Complexes. ADVANCES IN PHOTOSYNTHESIS AND RESPIRATION 2014. [DOI: 10.1007/978-94-017-9032-1_4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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12
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Krausz E. Selective and differential optical spectroscopies in photosynthesis. PHOTOSYNTHESIS RESEARCH 2013; 116:411-426. [PMID: 23839302 DOI: 10.1007/s11120-013-9881-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Accepted: 06/28/2013] [Indexed: 06/02/2023]
Abstract
Photosynthetic pigments are inherently intense optical absorbers and have strong polarisation characteristics. They can also luminesce strongly. These properties have led optical spectroscopies to be, quite naturally, key techniques in photosynthesis. However, there are typically many pigments in a photosynthetic assembly, which when combined with the very significant inhomogeneous and homogeneous linewidths characteristic of optical transitions, leads to spectral congestion. This in turn has made it difficult to provide a definitive and detailed electronic structure for many photosynthetic assemblies. An electronic structure is, however, necessary to provide a foundation for any complete description of fundamental processes in photosynthesis, particularly those in reaction centres. A wide range of selective and differential spectral techniques have been developed to help overcome the problems of spectral complexity and congestion. The techniques can serve to either reduce spectral linewidths and/or extract chromophore specific information from unresolved spectral features. Complementary spectral datasets, generated by a number of techniques, may then be combined in a 'multi-dimensional' theoretical analysis so as to constrain and define effective models of photosynthetic assemblies and their fundamental processes. A key example is the work of Renger and his group (Raszewski, Biophys J 88(2):986-998, 2005) on PS II reaction centre assemblies. This article looks to provide an overview of some of these techniques and indicate where their strengths and weaknesses may lie. It highlights some of our own contributions and indicates areas where progress may be possible.
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Affiliation(s)
- Elmars Krausz
- Research School of Chemistry, Australian National University, Building 35 Science Road, Canberra, ACT, 0200, Australia,
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13
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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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14
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Jankowiak R, Reppert M, Zazubovich V, Pieper J, Reinot T. Site Selective and Single Complex Laser-Based Spectroscopies: A Window on Excited State Electronic Structure, Excitation Energy Transfer, and Electron–Phonon Coupling of Selected Photosynthetic Complexes. Chem Rev 2011; 111:4546-98. [DOI: 10.1021/cr100234j] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ryszard Jankowiak
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | - Mike Reppert
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
| | - Valter Zazubovich
- Department of Physics, Concordia University, Montreal H4B1R6 Quebec, Canada
| | - Jörg Pieper
- Max-Volmer-Laboratories for Biophysical Chemistry, Technical University of Berlin, Germany
- Institute of Physics, University of Tartu, Riia 142, 51014 Tartu, Estonia
| | - Tonu Reinot
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, United States
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15
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Herascu N, Najafi M, Amunts A, Pieper J, Irrgang KD, Picorel R, Seibert M, Zazubovich V. Parameters of the protein energy landscapes of several light-harvesting complexes probed via spectral hole growth kinetics measurements. J Phys Chem B 2011; 115:2737-47. [PMID: 21391534 DOI: 10.1021/jp108775y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The parameters of barrier distributions on the protein energy landscape in the excited electronic state of the pigment/protein system have been determined by means of spectral hole burning for the lowest-energy pigments of CP43 core antenna complex and CP29 minor antenna complex of spinach Photosystem II (PS II) as well as of trimeric and monomeric LHCII complexes transiently associated with the pea Photosystem I (PS I) pool. All of these complexes exhibit sixty to several hundred times lower spectral hole burning yields as compared with molecular glassy solids previously probed by means of the hole growth kinetics measurements. Therefore, the entities (groups of atoms), which participate in conformational changes in protein, appear to be significantly larger and heavier than those in molecular glasses. No evidence of a small (∼1 cm(-1)) spectral shift tier of the spectral diffusion dynamics has been observed. Therefore, our data most likely reflect the true barrier distributions of the intact protein and not those related to the interface or surrounding host. Possible applications of the barrier distributions as well as the assignments of low-energy states of CP29 and LHCII are discussed in light of the above results.
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Affiliation(s)
- Nicoleta Herascu
- Department of Physics, Concordia University, Montreal, Quebec, Canada
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16
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Pieper J, Rätsep M, Trostmann I, Schmitt FJ, Theiss C, Paulsen H, Eichler H, Freiberg A, Renger G. Excitonic Energy Level Structure and Pigment−Protein Interactions in the Recombinant Water-Soluble Chlorophyll Protein. II. Spectral Hole-Burning Experiments. J Phys Chem B 2011; 115:4053-65. [DOI: 10.1021/jp111457t] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Pieper
- Max-Volmer-Laboratories for
Biophysical Chemistry, Berlin Institute of Technology, Berlin, Germany
| | - M. Rätsep
- Institute of Physics, University of Tartu, Tartu, Estonia
| | - I. Trostmann
- Institute of General Botany, Johannes Gutenberg University Mainz, Germany
| | - F.-J. Schmitt
- Max-Volmer-Laboratories for
Biophysical Chemistry, Berlin Institute of Technology, Berlin, Germany
- Institute of Optics and Atomic
Physics, Berlin Institute of Technology, Germany
| | - C. Theiss
- Institute of Optics and Atomic
Physics, Berlin Institute of Technology, Germany
| | - H. Paulsen
- Institute of General Botany, Johannes Gutenberg University Mainz, Germany
| | - H.J. Eichler
- Institute of Optics and Atomic
Physics, Berlin Institute of Technology, Germany
| | - A. Freiberg
- Institute of Physics, University of Tartu, Tartu, Estonia
- Institute of Molecular and Cell
Biology, University of Tartu, Tartu, Estonia
| | - G. Renger
- Max-Volmer-Laboratories for
Biophysical Chemistry, Berlin Institute of Technology, Berlin, Germany
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17
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van der Weij-de Wit CD, Dekker JP, van Grondelle R, van Stokkum IHM. Charge separation is virtually irreversible in photosystem II core complexes with oxidized primary quinone acceptor. J Phys Chem A 2011; 115:3947-56. [PMID: 21341818 DOI: 10.1021/jp1083746] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
X-ray structures of the Photosystem II (PSII) core revealed relatively large interpigment distances between the CP43 and CP47 antenna complexes and the reaction center (RC) with respect to the interpigment distances in a single unit. This finding questions the possibility of fast energy equilibration among the antenna and the RC, which has been the basic explanation for the measured PSII fluorescence kinetics for more than two decades. In this study, we present time-resolved fluorescence measurements obtained with a streak-camera setup on PSII core complexes from Thermosynechococcus elongatus at room temperature (RT) and at 77 K. Kinetic modeling of the RT data obtained with oxidized quinone acceptor Q(A), reveals that the kinetics are best described by fast primary charge separation at a time scale of 1.5 ps and slow energy transfer from the antenna into the RC, which results in an energy equilibration time between the antenna and the RC of about 44 ps. This model is consistent with structure-based computations. Primary radical pair formation was found to be a virtually irreversible process. Energy equilibration within the CP43 and CP47 complexes is shown to occur at a time scale of 8 ps. Kinetic modeling of the 77 K data reveals similar energy transfer time scales in the antenna units and among the antenna and the RC as at RT, respectively, 7 and 37 ps. We conclude that the energy transfer from the CP43/CP47 antenna to the RC is the dominant factor in the total charge separation kinetics in intact PSII cores.
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Affiliation(s)
- C D van der Weij-de Wit
- Department of Physics and Astronomy, Faculty of Sciences, VU University Amsterdam, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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18
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Reppert M, Acharya K, Neupane B, Jankowiak R. Lowest electronic states of the CP47 antenna protein complex of photosystem II: simulation of optical spectra and revised structural assignments. J Phys Chem B 2011; 114:11884-98. [PMID: 20722360 DOI: 10.1021/jp103995h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, we present simulated steady-state absorption, emission, and nonresonant hole burning (HB) spectra for the CP47 antenna complex of photosystem II (PS II) based on fits to recently refined experimental data (Neupane et al. J. Am. Chem. Soc. 2010, 132, 4214). Excitonic simulations are based on the 2.9 Å resolution structure of the PS II core from cyanobacteria (Guskov et al. Nat. Struct. Mol. Biol. 2009, 16, 334), and allow for preliminary assignment of the chlorophylls (Chls) contributing to the lowest excitonic states. The search for realistic site energies was guided by experimental constraints and aided by simple fitting algorithms. The following experimental constraints were used: (i) the oscillator strength of the lowest-energy state should be approximately ≤0.5 Chl equivalents; (ii) the excitonic structure must explain the experimentally observed red-shifted (∼695 nm) emission maximum; and (iii) the excitonic interactions of all states must properly describe the broad (non-line-narrowed, NLN) HB spectrum (including its antihole) whose shape is extremely sensitive to the excitonic structure of the complex, especially the lowest excitonic states. Importantly, our assignments differ significantly from those previously reported by Raszewski and Renger (J. Am. Chem. Soc. 2008, 130, 4431), due primarily to differences in the experimental data simulated. In particular, we find that the lowest state localized on Chl 526 possesses too high of an oscillator strength to fit low-temperature experimental data. Instead, we suggest that Chl 523 most strongly contributes to the lowest excitonic state, with Chl 526 contributing to the second excitonic state. Since the fits of nonresonant holes are more restrictive (in terms of possible site energies) than those of absorption and emission spectra, we suggest that fits of linear optical spectra along with HB spectra provide more realistic site energies.
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Affiliation(s)
- Mike Reppert
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA
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19
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Energy transfer processes in the isolated core antenna complexes CP43 and CP47 of photosystem II. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1606-16. [DOI: 10.1016/j.bbabio.2010.05.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 05/07/2010] [Accepted: 05/11/2010] [Indexed: 11/21/2022]
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20
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Neupane B, Dang NC, Acharya K, Reppert M, Zazubovich V, Picorel R, Seibert M, Jankowiak R. Insight into the electronic structure of the CP47 antenna protein complex of photosystem II: hole burning and fluorescence study. J Am Chem Soc 2010; 132:4214-29. [PMID: 20218564 DOI: 10.1021/ja908510w] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report low temperature (T) optical spectra of the isolated CP47 antenna complex from Photosystem II (PSII) with a low-T fluorescence emission maximum near 695 nm and not, as previously reported, at 690-693 nm. The latter emission is suggested to result from three distinct bands: a lowest-state emission band near 695 nm (labeled F1) originating from the lowest-energy excitonic state A1 of intact complexes (located near 693 nm and characterized by very weak oscillator strength) as well as emission peaks near 691 nm (FT1) and 685 nm (FT2) originating from subpopulations of partly destabilized complexes. The observation of the F1 emission is in excellent agreement with the 695 nm emission observed in intact PSII cores and thylakoid membranes. We argue that the band near 684 nm previously observed in singlet-minus-triplet spectra originates from a subpopulation of partially destabilized complexes with lowest-energy traps located near 684 nm in absorption (referred to as AT2) giving rise to FT2 emission. It is demonstrated that varying contributions from the F1, FT1, and FT2 emission bands led to different maxima of fluorescence spectra reported in the literature. The fluorescence spectra are consistent with the zero-phonon hole action spectra obtained in absorption mode, the profiles of the nonresonantly burned holes as a function of fluence, as well as the fluorescence line-narrowed spectra obtained for the Q(y) band. The lowest Q(y) state in absorption band (A1) is characterized by an electron-phonon coupling with the Huang-Rhys factor S of approximately 1 and an inhomogeneous width of approximately 180 cm(-1). The mean phonon frequency of the A1 band is 20 cm(-1). In contrast to previous observations, intact isolated CP47 reveals negligible contribution from the triplet-bottleneck hole, i.e., the AT2 trap. It has been shown that Chls in intact CP47 are connected via efficient excitation energy transfer to the A1 trap near 693 nm and that the position of the fluorescence maximum depends on the burn fluence. That is, the 695 nm fluorescence maximum shifts blue with increasing fluence, in agreement with nonresonant hole burned spectra. The above findings provide important constraints and parameters for future excitonic calculations, which in turn should offer new insight into the excitonic structure and composition of low-energy absorption traps.
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Affiliation(s)
- Bhanu Neupane
- Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA
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21
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Purchase R, Völker S. Spectral hole burning: examples from photosynthesis. PHOTOSYNTHESIS RESEARCH 2009; 101:245-66. [PMID: 19714478 PMCID: PMC2744831 DOI: 10.1007/s11120-009-9484-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Accepted: 07/31/2009] [Indexed: 05/14/2023]
Abstract
The optical spectra of photosynthetic pigment-protein complexes usually show broad absorption bands, often consisting of a number of overlapping, "hidden" bands belonging to different species. Spectral hole burning is an ideal technique to unravel the optical and dynamic properties of such hidden species. Here, the principles of spectral hole burning (HB) and the experimental set-up used in its continuous wave (CW) and time-resolved versions are described. Examples from photosynthesis studied with hole burning, obtained in our laboratory, are then presented. These examples have been classified into three groups according to the parameters that were measured: (1) hole widths as a function of temperature, (2) hole widths as a function of delay time and (3) hole depths as a function of wavelength. Two examples from light-harvesting (LH) 2 complexes of purple bacteria are given within the first group: (a) the determination of energy-transfer times from the chromophores in the B800 ring to the B850 ring, and (b) optical dephasing in the B850 absorption band. One example from photosystem II (PSII) sub-core complexes of higher plants is given within the second group: it shows that the size of the complex determines the amount of spectral diffusion measured. Within the third group, two examples from (green) plants and purple bacteria have been chosen for: (a) the identification of "traps" for energy transfer in PSII sub-core complexes of green plants, and (b) the uncovering of the lowest k = 0 exciton-state distribution within the B850 band of LH2 complexes of purple bacteria. The results prove the potential of spectral hole burning measurements for getting quantitative insight into dynamic processes in photosynthetic systems at low temperature, in particular, when individual bands are hidden within broad absorption bands. Because of its high-resolution wavelength selectivity, HB is a technique that is complementary to ultrafast pump-probe methods. In this review, we have provided an extensive bibliography for the benefit of scientists who plan to make use of this valuable technique in their future research.
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Affiliation(s)
- Robin Purchase
- Huygens and Gorlaeus Laboratories, Leiden University, 2300 RA Leiden, The Netherlands
| | - Silvia Völker
- Huygens and Gorlaeus Laboratories, Leiden University, 2300 RA Leiden, The Netherlands
- Department of Biophysics, Faculty of Exact Sciences, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
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22
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Krausz E, Cox N, Arsköld SP. Spectral characteristics of PS II reaction centres: as isolated preparations and when integral to PS II core complexes. PHOTOSYNTHESIS RESEARCH 2008; 98:207-17. [PMID: 18663598 DOI: 10.1007/s11120-008-9328-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Accepted: 07/03/2008] [Indexed: 05/22/2023]
Abstract
The discovery that the native PS II enzyme undergoes charge separation via an absorption extending to 730 nm has led us to re-examine the low-temperature absorption spectra of Nanba-Satoh PS II reaction centre preparations with particular focus on the long wavelength region. It is shown that these preparations do not exhibit absorption in the 700-730 nm region at 1.7 K. Absorption in the Nanba-Satoh type preparations analogous to the 'red tail' as observed in functional PS II core complexes is likely shifted to higher energy by >20 nm. Spectral changes associated with the stable reduction of pheo(a) in chemically treated reaction centre preparations are also revisited. Dithionite treatment of PS II preparations in the dark leads to changes of pigment-pigment and/or pigment-protein interactions, as evidenced by changes in absorption and CD spectra. Absorption and CD changes associated with stable Pheo(D1) photo-reduction in PS II core complexes and Nanba-Satoh preparations are compared. For Nanba-Satoh preparations, Q(y) bleaches are approximately 3x broader than in PS II core complexes and are blue-shifted by approximately 4 nm. These data are discussed in terms of current models of PS II, and suggest a need to consider protein-induced changes of some electronic properties of reaction centre pigments.
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Affiliation(s)
- Elmars Krausz
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia.
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23
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Croce R, Chojnicka A, Morosinotto T, Ihalainen JA, van Mourik F, Dekker JP, Bassi R, van Grondelle R. The low-energy forms of photosystem I light-harvesting complexes: spectroscopic properties and pigment-pigment interaction characteristics. Biophys J 2007; 93:2418-28. [PMID: 17545247 PMCID: PMC1965455 DOI: 10.1529/biophysj.107.106955] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this work the spectroscopic properties of the special low-energy absorption bands of the outer antenna complexes of higher plant Photosystem I have been investigated by means of low-temperature absorption, fluorescence, and fluorescence line-narrowing experiments. It was found that the red-most absorption bands of Lhca3, Lhca4, and Lhca1-4 peak, respectively, at 704, 708, and 709 nm and are responsible for 725-, 733-, and 732-nm fluorescence emission bands. These bands are more red shifted compared to "normal" chlorophyll a (Chl a) bands present in light-harvesting complexes. The low-energy forms are characterized by a very large bandwidth (400-450 cm(-1)), which is the result of both large homogeneous and inhomogeneous broadening. The observed optical reorganization energy is untypical for Chl a and resembles more that of BChl a antenna systems. The large broadening and the changes in optical reorganization energy are explained by a mixing of an Lhca excitonic state with a charge transfer state. Such a charge transfer state can be stabilized by the polar residues around Chl 1025. It is shown that the optical reorganization energy is changing through the inhomogeneous distribution of the red-most absorption band, with the pigments contributing to the red part of the distribution showing higher values. A second red emission form in Lhca4 was detected at 705 nm and originates from a broad absorption band peaking at 690 nm. This fluorescence emission is present also in the Lhca4-N-47H mutant, which lacks the 733-nm emission band.
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Affiliation(s)
- Roberta Croce
- Department of Biophysical Chemistry, Groningen Bimolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands.
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24
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Hughes JL, Picorel R, Seibert M, Krausz E. Photophysical Behavior and Assignment of the Low-Energy Chlorophyll States in the CP43 Proximal Antenna Protein of Higher Plant Photosystem II. Biochemistry 2006; 45:12345-57. [PMID: 17014087 DOI: 10.1021/bi0614683] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We have employed absorption, circular dichroism (CD), and persistent spectral hole-burning measurements at 1.7 K to study the photoconversion properties and exciton coupling of low-energy chlorophylls (Chls) in the CP43 proximal antenna light-harvesting subunit of photosystem II (PSII) isolated from spinach. These approximately 683 nm states act as traps for excitation energy in isolated CP43. They "bleach" at 683 nm upon illumination and photoconvert to a form absorbing in the range approximately 660-680 nm. We present new data that show the changes in the CD spectrum due to the photoconversion process. These changes occur in parallel with those in absorption, providing evidence that the feature undergoing the apparent bleach is a component of a weakly exciton-coupled system. From our photoconversion difference spectra, we assign four states in the Chl long-wavelength region of CP43, two of which are the known trap states and are both highly localized on single Chls. The other two states are associated with weak exciton coupling (maximally approximately 50 cm(-)(1)) to one of these traps. We propose a mechanism for photoconversion that involves Chl-protein hydrogen bonding. New hole-burning data are presented that indicate this mechanism is distinct to that for narrow-band spectral hole burning in CP43. We discuss the photophysical behavior of the Chl trap states in isolated CP43 compared to their behavior in intact PSII preparations. The latter represent a more intact, physiological complex, and we find no clear evidence that they exhibit the photoconversion process reported here.
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Affiliation(s)
- Joseph L Hughes
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia.
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Hughes JL, Smith P, Pace R, Krausz E. Charge separation in photosystem II core complexes induced by 690-730 nm excitation at 1.7 K. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2006; 1757:841-51. [PMID: 16859635 DOI: 10.1016/j.bbabio.2006.05.035] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 05/01/2006] [Accepted: 05/22/2006] [Indexed: 11/24/2022]
Abstract
The illumination of oxygen-evolving PSII core complexes at very low temperatures in spectral regions not expected to excite P680 leads to charge separation in a majority of centers. The fraction of centers photoconverted as a function of the number of absorbed photons per PSII core is determined by quantification of electrochromic shifts on Pheo(D1). These shifts arise from the formation of metastable plastoquinone anion (Q(A)(-)) configurations. Spectra of concentrated samples identify absorption in the 700-730 nm range. This is well beyond absorption attributable to CP47. Spectra in the 690-730 nm region can be described by the 'trap' CP47 absorption at 689 nm, with dipole strength of approximately 1 chlorophyll a (chl a), partially overlapping a broader feature near 705 nm with a dipole strength of approximately 0.15 chl a. This absorption strength in the 700-730 nm region falls by 40% in the photoconverted configuration. Quantum efficiencies of photoconversion following illumination in the 690-700 nm region are similar to those obtained with green illumination but fall significantly in the 700-730 nm range. Two possible assignments of the long-wavelength absorption are considered. Firstly, as a low intensity component of strongly exciton-coupled reaction center chlorin excitations and secondly as a nominally 'dark' charge-transfer excitation of the 'special pair' P(D1)-P(D2). The opportunities offered by these observations towards the understanding of the nature of P680 and PSII fluorescence are discussed.
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Affiliation(s)
- Joseph L Hughes
- Research School of Chemistry, Australian National University, Canberra
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Krausz E, Hughes JL, Smith PJ, Pace RJ, Arsköld SP. Assignment of the low-temperature fluorescence in oxygen-evolving photosystem II. PHOTOSYNTHESIS RESEARCH 2005; 84:193-9. [PMID: 16049774 DOI: 10.1007/s11120-004-7078-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2004] [Accepted: 12/02/2004] [Indexed: 05/03/2023]
Abstract
Low-temperature absorption and fluorescence spectra of fully active cores and membrane-bound PS II preparations are compared. Detailed temperature dependence of fluorescence spectra between 5 and 70 K are presented as well as 1.7-K fluorescence line-narrowed (FLN) spectra of cores, confirming that PS II emission is composite. Spectra are compared to those reported for LHCII, CP43, CP47 and D1/D2/cytit b559 subunits of PS II. A combination of subunit spectra cannot account for emission of active PS II. The complex temperature dependence of PS II fluorescence is interpretable by noting that excitation transfer from CP43 and CP47 to the reaction centre is slow, and strongly dependent on the precise energy at which a 'slow-transfer' pigment in CP43 or CP47 is located within its inhomogeneous distribution. PS II fluorescence arises from CP43 and CP47 'slow-transfer' states, convolved by this dependence. At higher temperatures, thermally activated excitation transfer to the PS II charge-separating system bypasses such bottlenecks. As the charge-separating state of active PS II absorbs at >700 nm, PS II emission in the 680-700 nm region is unlikely to arise from reaction centre pigments. PS II emission at physiological temperatures is discussed in terms of these results.
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Affiliation(s)
- Elmars Krausz
- Research School of Chemistry, Australian National University, Building 35 Science Road, Canberra, ACT 0200, Australia.
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Bonsma S, Purchase R, Jezowski S, Gallus J, Könz F, Völker S. Green and red fluorescent proteins: photo- and thermally induced dynamics probed by site-selective spectroscopy and hole burning. Chemphyschem 2005; 6:838-49. [PMID: 15884066 DOI: 10.1002/cphc.200500005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2005] [Indexed: 11/12/2022]
Abstract
The cloning and expression of autofluorescent proteins in living matter, combined with modern imaging techniques, have thoroughly changed the world of bioscience. In particular, such proteins are widely used as genetically encoded labels to track the movement of proteins as reporters of cellular signals and to study protein-protein interactions by fluorescence resonance energy transfer (FRET). Their optical properties, however, are complex and it is important to understand these for the correct interpretation of imaging data and for the design of new fluorescent mutants. In this Minireview we start with a short survey of the field and then focus on the photo- and thermally induced dynamics of green and red fluorescent proteins. In particular, we show how fluorescence line narrowing and high-resolution spectral hole burning at low temperatures can be used to unravel the photophysics and photochemistry and shed light on the intricate electronic structure of these proteins.
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Affiliation(s)
- S Bonsma
- Huygens and Gorlaeus Laboratories, Leiden University, P.O. Box 9504, 2300 RA Leiden, The Netherlands
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28
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Croce R, Morosinotto T, Ihalainen JA, Chojnicka A, Breton J, Dekker JP, van Grondelle R, Bassi R. Origin of the 701-nm Fluorescence Emission of the Lhca2 Subunit of Higher Plant Photosystem I. J Biol Chem 2004; 279:48543-9. [PMID: 15328342 DOI: 10.1074/jbc.m408908200] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photosystem I of higher plants is characterized by red-shifted spectral forms deriving from chlorophyll chromophores. Each of the four Lhca1 to -4 subunits exhibits a specific fluorescence emission spectrum, peaking at 688, 701, 725, and 733 nm, respectively. Recent analysis revealed the role of chlorophyll-chlorophyll interactions of the red forms in Lhca3 and Lhca4, whereas the basis for the fluorescence emission at 701 nm in Lhca2 is not yet clear. We report a detailed characterization of the Lhca2 subunit using molecular biology, biochemistry, and spectroscopy and show that the 701-nm emission form originates from a broad absorption band at 690 nm. Spectroscopy on recombinant mutant proteins assesses that this band represents the low energy form of an excitonic interaction involving two chlorophyll a molecules bound to sites A5 and B5, the same protein domains previously identified for Lhca3 and Lhca4. The resulting emission is, however, substantially shifted to higher energies. These results are discussed on the basis of the structural information that recently became available from x-ray crystallography (Ben Shem, A., Frolow, F., and Nelson, N. (2003) Nature 426, 630-635). We suggest that, within the Lhca subfamily, spectroscopic properties of chromophores are modulated by the strength of the excitonic coupling between the chromophores A5 and B5, thus yielding fluorescence emission spanning a large wavelength interval. It is concluded that the interchromophore distance rather than the transition energy of the individual chromophores or the orientation of transition vectors represents the critical factor in determining the excitonic coupling in Lhca pigment-protein complexes.
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Affiliation(s)
- Roberta Croce
- Istituto di Biofisica, CNR, Trento, c/o ITC via Sommarive 18, Povo, Trento 38100, Italy.
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29
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Hughes JL, Prince BJ, Krausz E, Smith PJ, Pace RJ, Riesen H. Highly Efficient Spectral Hole-Burning in Oxygen-Evolving Photosystem II Preparations. J Phys Chem B 2004. [DOI: 10.1021/jp0492523] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph L. Hughes
- Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia, Faculties Chemistry, The Australian National University, Canberra ACT 0200, Australia, and School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra ACT 2600, Australia
| | - Barry J. Prince
- Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia, Faculties Chemistry, The Australian National University, Canberra ACT 0200, Australia, and School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra ACT 2600, Australia
| | - Elmars Krausz
- Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia, Faculties Chemistry, The Australian National University, Canberra ACT 0200, Australia, and School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra ACT 2600, Australia
| | - Paul J. Smith
- Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia, Faculties Chemistry, The Australian National University, Canberra ACT 0200, Australia, and School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra ACT 2600, Australia
| | - Ron J. Pace
- Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia, Faculties Chemistry, The Australian National University, Canberra ACT 0200, Australia, and School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra ACT 2600, Australia
| | - Hans Riesen
- Research School of Chemistry, The Australian National University, Canberra ACT 0200, Australia, Faculties Chemistry, The Australian National University, Canberra ACT 0200, Australia, and School of Physical, Environmental and Mathematical Sciences, University College, The University of New South Wales, ADFA, Canberra ACT 2600, Australia
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Groot ML, Breton J, van Wilderen LJGW, Dekker JP, van Grondelle R. Femtosecond Visible/Visible and Visible/Mid-IR Pump−Probe Study of the Photosystem II Core Antenna Complex CP47. J Phys Chem B 2004. [DOI: 10.1021/jp037966s] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Marie Louise Groot
- Faculty of Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands, and Service de Bioénergétique, Bât. 532, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - Jacques Breton
- Faculty of Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands, and Service de Bioénergétique, Bât. 532, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - Luuk J. G. W. van Wilderen
- Faculty of Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands, and Service de Bioénergétique, Bât. 532, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - Jan P. Dekker
- Faculty of Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands, and Service de Bioénergétique, Bât. 532, CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - Rienk van Grondelle
- Faculty of Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands, and Service de Bioénergétique, Bât. 532, CEA-Saclay, 91191 Gif-sur-Yvette, France
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31
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Arsköld SP, Masters VM, Prince BJ, Smith PJ, Pace RJ, Krausz E. Optical spectra of synechocystis and spinach photosystem II preparations at 1.7 K: identification of the D1-pheophytin energies and stark shifts. J Am Chem Soc 2004; 125:13063-74. [PMID: 14570479 DOI: 10.1021/ja034548s] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report and compare highly resolved, simultaneously recorded absorption and CD spectra of active Photosystem II (PSII) samples in the range 440-750 nm. From an appropriately scaled comparison of spinach membrane fragment (BBY) and PSII core spectra, we show that key features of the core spectrum are quantitatively represented in the BBY data. PSII from the cyanobacterium Synechocystis 6803 display spectral features in the Qy region of comparable width (50-70 cm(-1) fwhm) to those seen in plant PSII but the energies of the resolved features are distinctly different. A comparison of spectra taken of PSII poised in the S1QA and S2QA(-) redox states reveals electrochromic shifts largely attributable to the influence of QA(-) on Pheo(D1). This allows accurate determinations of the Pheo(D1) Qy absorption positions to be at 685.0 nm for spinach cores, 685.8 nm for BBY particles, and 683.0 nm for Synechocystis. These are discussed in terms of earlier reports of the Pheo(D1) energies in PSII. The Qx transition of Pheo(D1) undergoes a blue shift upon Q(A) reduction, and we place a lower limit of 80 cm(-1) on this shift in plant material. By comparing the magnitude of the Stark shifts of the Qx and Qy bands of Pheo(D1), the directions of the transition-induced dipole moment changes, Deltamu(x) and Deltamu(y), for this functionally important pigment could be determined, assuming normal magnitudes of the Deltamu's. Consequently, Deltamu(x) and Deltamu(y) are determined to be approximately orthogonal to the directions expected for these transitions. Low-fluence illumination experiments at 1.7 K resulted in very efficient formation of QA(-). This was accompanied by cyt b(559) oxidation in BBYs and carotenoid oxidation in cores. No chlorophyll oxidation was observed. Our data allow us to estimate the quantum efficiency of PSII at this temperature to be of the order 0.1-1. No Stark shift associated with the S1-to-S2 transition of the Mn cluster is evident in our samples. The similarity of Stark data in plants and Synechocystis points to minimal interactions of Pheo(D1) with nearby chloropyll pigments in active PSII preparations. This appears to be at variance with interpretations of experiments performed with inactive solubilized reaction-center preparations.
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Affiliation(s)
- Sindra Peterson Arsköld
- Research School of Chemistry and Department of Chemistry, Faculties of Science, Australian National University, Canberra ACT 0200, Australia.
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De Weerd FL, Palacios MA, Andrizhiyevskaya EG, Dekker JP, Van Grondelle R. Identifying the lowest electronic states of the chlorophylls in the CP47 core antenna protein of photosystem II. Biochemistry 2002; 41:15224-33. [PMID: 12484760 DOI: 10.1021/bi0261948] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
CP47 is a pigment-protein complex in the core of photosystem II that tranfers excitation energy to the reaction center. Here we report on a spectroscopic investigation of the isolated CP47 complex. By deconvoluting the 77 K absorption and linear dichroism, red-most states at 683 and 690 nm have been identified with oscillator strengths corresponding to approximately 3 and approximately 1 chlorophyll, respectively. Both states contribute to the 4 K emission, and the Stark spectrum shows that they have a large value for the difference polarizability between their ground and excited states. From site-selective polarized triplet-minus-singlet spectra, an excitonic origin for the 683 nm state was found. The red shift of the 690 nm state is most probably due to strong hydrogen bonding to a protein ligand, as follows from the position of the stretch frequency of the chlorophyll 13(1) keto group (1633 cm(-)(1)) in the fluorescence line narrowing spectrum at 4 K upon red-most excitation. We discuss how the 683 and 690 nm states may be linked to specific chlorophylls in the crystal structure [Zouni, A., Witt, H.-T., Kern, J., Fromme, P., Krauss, N., Saenger, W., and Orth, P. (2001) Nature 409, 739-743].
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Affiliation(s)
- Frank L De Weerd
- Faculty of Sciences, Division of Physics and Astronomy, Department of Biophysics and Physics of Complex Systems, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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33
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de Weerd FL, van Stokkum IHM, van Amerongen H, Dekker JP, van Grondelle R. Pathways for energy transfer in the core light-harvesting complexes CP43 and CP47 of photosystem II. Biophys J 2002; 82:1586-97. [PMID: 11867471 PMCID: PMC1301957 DOI: 10.1016/s0006-3495(02)75510-0] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The pigment-protein complexes CP43 and CP47 transfer excitation energy from the peripheral antenna of photosystem II toward the photochemical reaction center. We measured the excitation dynamics of the chlorophylls in isolated CP43 and CP47 complexes at 77 K by time-resolved absorbance-difference and fluorescence spectroscopy. The spectral relaxation appeared to occur with rates of 0.2-0.4 ps and 2-3 ps in both complexes, whereas an additional relaxation of 17 ps was observed only in CP47. Using the 3.8-A crystal structure of the photosystem II core complex from Synechococcus elongatus (A. Zouni, H.-T. Witt, J. Kern, P. Fromme, N. Krauss, W. Saenger, and P. Orth, 2001, Nature, 409:739-743), excitation energy transfer kinetics were calculated and a Monte Carlo simulation of the absorption spectra was performed. In both complexes, the rate of 0.2-0.4 ps can be ascribed to excitation energy transfer within a layer of chlorophylls near the stromal side of the membrane, and the slower 2-3-ps process to excitation energy transfer to the calculated lowest excitonic state. We conclude that excitation energy transfer within CP43 and CP47 is fast and does not contribute significantly to the well-known slow trapping of excitation energy in photosystem II.
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Affiliation(s)
- Frank L de Weerd
- Department of Biophysics and Physics of Complex Systems, Division of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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34
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Pieper J, Schödel R, Irrgang KD, Voigt J, Renger G. Electron−Phonon Coupling in Solubilized LHC II Complexes of Green Plants Investigated by Line-Narrowing and Temperature-Dependent Fluorescence Spectroscopy. J Phys Chem B 2001. [DOI: 10.1021/jp010229g] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Pieper
- Institute of Physics, Humboldt University, 10099 Berlin, Germany, and Max-Volmer-Institute for Biophysical Chemistry and Biochemistry, Technical University, 10623 Berlin, Germany
| | - R. Schödel
- Institute of Physics, Humboldt University, 10099 Berlin, Germany, and Max-Volmer-Institute for Biophysical Chemistry and Biochemistry, Technical University, 10623 Berlin, Germany
| | - K.-D. Irrgang
- Institute of Physics, Humboldt University, 10099 Berlin, Germany, and Max-Volmer-Institute for Biophysical Chemistry and Biochemistry, Technical University, 10623 Berlin, Germany
| | - J. Voigt
- Institute of Physics, Humboldt University, 10099 Berlin, Germany, and Max-Volmer-Institute for Biophysical Chemistry and Biochemistry, Technical University, 10623 Berlin, Germany
| | - G. Renger
- Institute of Physics, Humboldt University, 10099 Berlin, Germany, and Max-Volmer-Institute for Biophysical Chemistry and Biochemistry, Technical University, 10623 Berlin, Germany
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35
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Matsuzaki S, Zazubovich V, Fraser NJ, Cogdell RJ, Small GJ. Energy Transfer Dynamics in LH2 Complexes of Rhodopseudomonas acidophila Containing Only One B800 Molecule. J Phys Chem B 2001. [DOI: 10.1021/jp0037347] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- S. Matsuzaki
- Ames Laboratory, U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, and Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, G128 QQ, United Kingdom
| | - V. Zazubovich
- Ames Laboratory, U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, and Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, G128 QQ, United Kingdom
| | - N. J. Fraser
- Ames Laboratory, U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, and Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, G128 QQ, United Kingdom
| | - R. J. Cogdell
- Ames Laboratory, U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, and Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, G128 QQ, United Kingdom
| | - G. J. Small
- Ames Laboratory, U.S. Department of Energy and Department of Chemistry, Iowa State University, Ames, Iowa 50011, and Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, G128 QQ, United Kingdom
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36
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Reinot T, Zazubovich V, Hayes JM, Small GJ. New Insights on Persistent Nonphotochemical Hole Burning and Its Application to Photosynthetic Complexes. J Phys Chem B 2001. [DOI: 10.1021/jp010126y] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Tonu Reinot
- Department of Chemistry and Ames Laboratory-U.S. Department of Energy, Iowa State University, Ames, Iowa 50011
| | - Valter Zazubovich
- Department of Chemistry and Ames Laboratory-U.S. Department of Energy, Iowa State University, Ames, Iowa 50011
| | - John M. Hayes
- Department of Chemistry and Ames Laboratory-U.S. Department of Energy, Iowa State University, Ames, Iowa 50011
| | - Gerald J. Small
- Department of Chemistry and Ames Laboratory-U.S. Department of Energy, Iowa State University, Ames, Iowa 50011
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37
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Jankowiak R, Zazubovich V, Rätsep M, Matsuzaki S, Alfonso M, Picorel R, Seibert M, Small GJ. The CP43 Core Antenna Complex of Photosystem II Possesses Two Quasi-Degenerate and Weakly Coupled Qy-Trap States. J Phys Chem B 2000. [DOI: 10.1021/jp0025431] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. Jankowiak
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - V. Zazubovich
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - M. Rätsep
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - S. Matsuzaki
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - M. Alfonso
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - R. Picorel
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - M. Seibert
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
| | - G. J. Small
- Ames Laboratory-USDOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, E. E. Aula Dei, CSIC, 50080-Zaragoza, Spain, and National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado 80401
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38
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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
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39
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Finzi L, Zucchelli G, Garlaschi FM, Jennings RC. Thermal sensitivity of the red absorption tail of the photosystem II reaction center complex. Biochemistry 1999; 38:10627-31. [PMID: 10451356 DOI: 10.1021/bi990568o] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The red tail of the absorption spectrum of the D1-D2-cytb559 complex, defined as the absorption signal not described by the two Gaussian sub-bands associated with the intense electronic transitions at 680 and 683 nm, exhibits anomalous temperature behavior. This tail was analyzed in the temperature interval between 80 and 300 K in terms of the mean square deviation (sigma2) of the total Qy absorption band and by Gaussian sub-band decomposition. The value of the average optical reorganization energy (Snum) obtained from the temperature dependence of sigma2 for the whole absorption band was 32 cm(-1), and changed to 16-20 cm(-1) after subtraction of the sub-bands describing the red tail. This latter value is in agreement with the hole burning literature data for chlorophyll bound to proteins, and indicates that the rather high value for the apparent optical reorganization energy obtained by analysis of the total Qy band of the D1-D2-cytb559 complex is determined by the temperature sensitivity of the red tail. This suggests that the long wavelength absorption tail might be due to vibrational transitions associated with vibrational modes in the range of 80-150 cm(-1) which are thermally accessible and give rise to an absorption signal on the low-energy side of the (0,0) transition. On the basis of this assumption, the electron-phonon coupling strength (S) for these modes is estimated to be in the range 0.028-0.18. This interpretation furthermore supports the idea that the electronic transition near 683 nm is that of a monomer chlorophyll.
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Affiliation(s)
- L Finzi
- Dipartimento di Biologia, Universita' degli Studi di Milano, Centro CNR Biologia Cellulare e Molecolare delle Piante, Italy
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40
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den Hartog FTH, van Papendrecht C, Störkel U, Völker S. Protein Dynamics in Photosystem II Complexes of Green Plants Studied by Time-Resolved Hole-Burning. J Phys Chem B 1999. [DOI: 10.1021/jp984484l] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- F. T. H. den Hartog
- Center for the Study of Excited States of Molecules, Huygens and Gorlaeus Laboratories, University of Leiden, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Faculty of Exact Sciences, Free University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - C. van Papendrecht
- Center for the Study of Excited States of Molecules, Huygens and Gorlaeus Laboratories, University of Leiden, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Faculty of Exact Sciences, Free University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - U. Störkel
- Center for the Study of Excited States of Molecules, Huygens and Gorlaeus Laboratories, University of Leiden, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Faculty of Exact Sciences, Free University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - S. Völker
- Center for the Study of Excited States of Molecules, Huygens and Gorlaeus Laboratories, University of Leiden, P.O. Box 9504, 2300 RA Leiden, The Netherlands, and Department of Biophysics, Faculty of Exact Sciences, Free University, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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