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Li X, Buda F, de Groot HJ, Sevink GJA. Contrasting Modes of Self-Assembly and Hydrogen-Bonding Heterogeneity in Chlorosomes of Chlorobaculum tepidum. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2018; 122:14877-14888. [PMID: 30258522 PMCID: PMC6150686 DOI: 10.1021/acs.jpcc.8b01790] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 05/30/2018] [Indexed: 06/08/2023]
Abstract
Chlorosome antennae form an interesting class of materials for studying the role of structural motifs and dynamics in nonadiabatic energy transfer. They perform robust and highly quantum-efficient transfer of excitonic energy while allowing for compositional variation and completely lacking the usual regulatory proteins. Here, we first cast the geometrical analysis for ideal tubular scaffolding models into a formal framework, to relate effective helical properties of the assembly structures to established characterization data for various types of chlorosomes. This analysis shows that helicity is uniquely defined for chlorosomes composed of bacteriochlorophyll (BChl) d and that three chiral angles are consistent with the nuclear magnetic resonance (NMR) and electron microscope data for BChl c, including two novel ones that are at variance with current interpretations of optical data based on perfect cylindrical symmetry. We use this information as a starting point for investigating dynamic and static heterogeneity at the molecular level by unconstrained molecular dynamics. We first identify a rotational degree of freedom, along the Mg-OH coordination bond, that alternates along the syn-anti stacks and underlies the (flexible) curvature on a larger scale. Because rotation directly relates to the formation or breaking of interstack hydrogen bonds of the O-H···O=C structural motif along the syn-anti stacks, we analyzed the relative fractions of hydrogen-bonded and the nonbonded regions, forming stripe domains in otherwise spectroscopically homogeneous curved slabs. The ratios 7:3 for BChl c and 9:1 for BChl d for the two distinct structural components agree well with the signal intensities determined by NMR. In addition, rotation with curvature-independent formation of stripe domains offers a viable explanation for the localization and dispersion of exciton states over two fractions, as observed in single chlorosome fluorescence decay studies.
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Yakovlev A, Novoderezhkin V, Taisova A, Shuvalov V, Fetisova Z. Orientation of B798 BChl a Q y transition dipoles in Chloroflexus aurantiacus chlorosomes: polarized transient absorption spectroscopy studies. PHOTOSYNTHESIS RESEARCH 2015; 125:31-42. [PMID: 25515768 DOI: 10.1007/s11120-014-0060-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/16/2014] [Indexed: 06/04/2023]
Abstract
Isotropic and anisotropic pump-probe spectra of Cfx. aurantiacus chlorosomes were measured on the fs-through ps-time scales for the B798 BChl a Q y band upon direct excitation of the B798 band at T = 293 K and T = 90 K. Upon direct excitation of the B798 band, the anisotropy parameter value r(λ) was constant within the whole BChl a Q y band at any delay time at both temperatures. The value of the anisotropy parameter r decayed from r = 0.4 at both temperatures (at 200 fs delay time after excitation) to the steady-state values r = 0.1 at T = 293 K and to r = 0.09 at T = 90 K (at 30 ÷ 100 ps delay time after excitation). The results were considered within the framework of the model of uniaxial orientation distribution of BChl-a transition dipoles within a single Cfx. aurantiacus chlorosome. This implies that the B798 BChl a Q y transition dipoles, randomly distributed around the normal to the baseplate plane, form the angle θ with the plane. For this model, the theoretical dependence of the steady-state anisotropy parameter r on the angle θ was derived. According to the theoretical dependence r(θ), the angle θ corresponding to the experimental steady-state value r = 0.1 at T = 293 K was found to equal 55°. As the temperature drops to 90 K, the angle θ decreases to 54°.
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Affiliation(s)
- Andrei Yakovlev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, 119991, Moscow, Russian Federation
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Tian Y, Camacho R, Thomsson D, Reus M, Holzwarth AR, Scheblykin IG. Organization of bacteriochlorophylls in individual chlorosomes from Chlorobaculum tepidum studied by 2-dimensional polarization fluorescence microscopy. J Am Chem Soc 2011; 133:17192-9. [PMID: 21923120 DOI: 10.1021/ja2019959] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Chlorosomes are the largest and most efficient natural light-harvesting systems and contain supramolecular assemblies of bacteriochlorophylls that are organized without proteins. Despite a recent structure determination for chlorosomes from Chlorobaculum tepidum (Ganapathy Proc. Natl. Acad. Sci. U.S.A. 2009, 106, 8525), the issue of a possible large structural disorder is still discussed controversially. We have studied individual chlorosomes prepared under very carefully controlled growth condition by a novel 2-dimensional polarization single molecule imaging technique giving polarization information for both fluorescence excitation and emission simultaneously. Contrary to the existing literature data, the polarization degree or modulation depth (M) for both excitation (absorption) and emission (fluorescence) showed extremely narrow distributions. The fluorescence was always highly polarized with M ≈ 0.77, independent of the excitation wavelength. Moreover, the fluorescence spectra of individual chlorosomes were identical within the error limits. These results lead us to conclude that all chlorosomes possess the same type of internal organization in terms of the arrangement of the bacteriochlorophyll c transition dipole moments and their total excitonic transition dipole possess a cylindrical symmetry in agreement with the previously suggested concentric multitubular chlorophyll aggregate organization (Ganapathy Proc. Natl. Acad. Sci. U.S.A. 2009, 106, 8525).
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Affiliation(s)
- Yuxi Tian
- Chemical Physics, Lund University, Lund, Sweden
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Oostergetel GT, van Amerongen H, Boekema EJ. The chlorosome: a prototype for efficient light harvesting in photosynthesis. PHOTOSYNTHESIS RESEARCH 2010; 104:245-55. [PMID: 20130996 PMCID: PMC2882566 DOI: 10.1007/s11120-010-9533-0] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Accepted: 01/16/2010] [Indexed: 05/18/2023]
Abstract
Three phyla of bacteria include phototrophs that contain unique antenna systems, chlorosomes, as the principal light-harvesting apparatus. Chlorosomes are the largest known supramolecular antenna systems and contain hundreds of thousands of BChl c/d/e molecules enclosed by a single membrane leaflet and a baseplate. The BChl pigments are organized via self-assembly and do not require proteins to provide a scaffold for efficient light harvesting. Their excitation energy flows via a small protein, CsmA embedded in the baseplate to the photosynthetic reaction centres. Chlorosomes allow for photosynthesis at very low light intensities by ultra-rapid transfer of excitations to reaction centres and enable organisms with chlorosomes to live at extraordinarily low light intensities under which no other phototrophic organisms can grow. This article reviews several aspects of chlorosomes: the supramolecular and molecular organizations and the light-harvesting and spectroscopic properties. In addition, it provides some novel information about the organization of the baseplate.
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Affiliation(s)
- Gert T. Oostergetel
- Biophysical Chemistry, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, The Netherlands
| | - Egbert J. Boekema
- Biophysical Chemistry, Groningen Biomolecular Sciences & Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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van Grondelle R, Monshouwer R, Valkunas L. Photosynthetic antennae. Photosynthetic light-harvesting. ACTA ACUST UNITED AC 2010. [DOI: 10.1002/bbpc.19961001204] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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6
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Spectral properties of single light-harvesting complexes in bacterial photosynthesis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY C-PHOTOCHEMISTRY REVIEWS 2010. [DOI: 10.1016/j.jphotochemrev.2010.02.002] [Citation(s) in RCA: 156] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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7
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Linearly polarized light absorption spectra of chlorosomes, light-harvesting antennas of photosynthetic green sulfur bacteria. Chem Phys Lett 2010. [DOI: 10.1016/j.cplett.2009.12.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Garab G, van Amerongen H. Linear dichroism and circular dichroism in photosynthesis research. PHOTOSYNTHESIS RESEARCH 2009; 101:135-46. [PMID: 19418239 PMCID: PMC2744782 DOI: 10.1007/s11120-009-9424-4] [Citation(s) in RCA: 110] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Accepted: 04/10/2009] [Indexed: 05/18/2023]
Abstract
The efficiency of photosynthetic light energy conversion depends largely on the molecular architecture of the photosynthetic membranes. Linear- and circular-dichroism (LD and CD) studies have contributed significantly to our knowledge of the molecular organization of pigment systems at different levels of complexity, in pigment-protein complexes, supercomplexes, and their macroassemblies, as well as in entire membranes and membrane systems. Many examples show that LD and CD data are in good agreement with structural data; hence, these spectroscopic tools serve as the basis for linking the structure of photosynthetic pigment-protein complexes to steady-state and time-resolved spectroscopy. They are also indispensable for identifying conformations and interactions in native environments, and for monitoring reorganizations during photosynthetic functions, and are important in characterizing reconstituted and artificially constructed systems. This educational review explains, in simple terms, the basic physical principles, and theory and practice of LD and CD spectroscopies and of some related quantities in the areas of differential polarization spectroscopy and microscopy.
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Affiliation(s)
- Győző Garab
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 521, 6701 Szeged, Hungary
| | - Herbert van Amerongen
- Laboratory of Biophysics, Wageningen University, P.O. Box 8128, 6700 ET Wageningen, The Netherlands
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Shibata Y, Saga Y, Tamiaki H, Itoh S. Anisotropic distribution of emitting transition dipoles in chlorosome from Chlorobium tepidum: fluorescence polarization anisotropy study of single chlorosomes. PHOTOSYNTHESIS RESEARCH 2009; 100:67-78. [PMID: 19468858 DOI: 10.1007/s11120-009-9429-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 04/23/2009] [Indexed: 05/27/2023]
Abstract
The polarization anisotropy of fluorescence spectra from single chlorosomes isolated from a green sulfur bacterium, Chlorobium (Cb.) tepidum, was observed at 13 K. As the polarizer was rotated, the intensities of the fluorescence bands of both bacteriochlorophyll (BChl)-c self-aggregates and BChl-a in baseplate proteins showed clear oscillations. From the oscillation, the values of the degree of polarization (DP) and the phase shift (PS) between the BChl-c and BChl-a bands were determined for each single chlorosome. The DP versus PS plot for Cb. tepidum chlorosomes showed linear correlations between the PS and the DP values for both BChl-c and BChl-a fluorescence bands. This tendency could be explained from a simulation assuming a random orientation of chlorosomes and a triaxial orientation distribution of emitting transition dipoles within a single chlorosome. The intensity ratios among the X-/Y-/Z-principal transition dipoles were estimated to be 0.3/0.5/1 and 1/0.6/0.1 for the BChl-c and BChl-a fluorescence bands, respectively. Here, the X-, Y-, and Z-axes are perpendicular, parallel to the cytoplasmic membrane, and parallel to the chlorosome long axis, respectively. A theoretical calculation based on the exciton theory was conducted to reproduce the observed triaxial orientation distribution of emitting transition dipoles. The simulation revealed that a deformation introduced to the circular cross section of the rod-shaped BChl-c self-aggregates could qualitatively reproduce results of this study.
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Affiliation(s)
- Yutaka Shibata
- Department of Physics, Graduate School of Science, Nagoya University, Nagoya, 464-8602, Japan.
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Linnanto JM, Korppi-Tommola JEI. Investigation on chlorosomal antenna geometries: tube, lamella and spiral-type self-aggregates. PHOTOSYNTHESIS RESEARCH 2008; 96:227-245. [PMID: 18443917 DOI: 10.1007/s11120-008-9304-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 04/07/2008] [Indexed: 05/26/2023]
Abstract
Molecular mechanics calculations and exciton theory have been used to study pigment organization in chlorosomes of green bacteria. Single and double rod, multiple concentric rod, lamella, and Archimedean spiral macrostructures of bacteriochlorophyll c molecules were created and their spectral properties evaluated. The effects of length, width, diameter, and curvature of the macrostructures as well as orientations of monomeric transition dipole moment vectors on the spectral properties of the aggregates were studied. Calculated absorption, linear dichroism, and polarization dependent fluorescence-excitation spectra of the studied long macrostructures were practically identical, but circular dichroism spectra turned out to be very sensitive to geometry and monomeric transition dipole moment orientations of the aggregates. The simulations for long multiple rod and spiral-type macrostructures, observed in recent high-resolution electron microscopy images (Oostergetel et al., FEBS Lett 581:5435-5439, 2007) gave shapes of circular dichroism spectra observed experimentally for chlorosomes. It was shown that the ratio of total circular dichroism intensity to integrated absorption of the Q(y) transition is a good measure of degree of tubular structures in the chlorosomes. Calculations suggest that the broad Q(y) line width of chlorosomes of sulfur bacteria could be due to (1) different orientations of the transition moment vectors in multi-walled rod structures or (2) a variety of Bchl-aggregate structures in the chlorosomes.
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Affiliation(s)
- Juha M Linnanto
- Department of Chemistry, University of Jyväskylä, Jyväskylä, Finland.
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Shibata Y, Saga Y, Tamiaki H, Itoh S. Polarized Fluorescence of Aggregated Bacteriochlorophyll c and Baseplate Bacteriochlorophyll a in Single Chlorosomes Isolated from Chloroflexus aurantiacus. Biochemistry 2007; 46:7062-8. [PMID: 17503774 DOI: 10.1021/bi0623072] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The polarization anisotropy of fluorescence from single chlorosomes isolated from a green filamentous bacterium, Chloroflexus aurantiacus, was measured using a confocal laser microscope at 13 K. Each single chlorosome that is floating in a frozen solvent exhibited strong polarization anisotropy of fluorescence. We calculated the degrees of fluorescence polarization for 51 floating single chlorosomes. The value ranged from 0.1 to 0.76 for the BChl-c aggregate in the core chlorosomes and from 0 to 0.4 for the energy acceptor BChl-a in the baseplate protein in the outer membrane. The shifts in polarization angles between the two emission bands were distributed over all the possible values with a sharp peak around 90 degrees , suggesting the perpendicular orientation between the transition dipoles of the fluorescence emission from the BChl-c aggregate and that from BChl-a. A simulation assuming a random orientation of chlorosomes reproduced the experimental results exactly. The analysis further indicated the appreciable contribution of the transition dipole of BChl-c that has an orientation perpendicular to the major polarization axis in each chlorosome. Small values of the degrees of polarization implied the BChl-a transition dipole to be somewhat tilted with respect to the normal of the cytoplasmic membrane to which chlorosomes are attached. These conclusions can be obtained only by observing the fluorescence of single chlorosomes.
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Affiliation(s)
- Yutaka Shibata
- Division of Material Science (Physics), Graduate School of Science, Nagoya University, Nagoya 464-8602, Japan.
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Psencík J, Ma YZ, Arellano JB, Hála J, Gillbro T. Excitation energy transfer dynamics and excited-state structure in chlorosomes of Chlorobium phaeobacteroides. Biophys J 2003; 84:1161-79. [PMID: 12547796 PMCID: PMC1302692 DOI: 10.1016/s0006-3495(03)74931-5] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The excited-state relaxation within bacteriochlorophyll (BChl) e and a in chlorosomes of Chlorobium phaeobacteroides has been studied by femtosecond transient absorption spectroscopy at room temperature. Singlet-singlet annihilation was observed to strongly influence both the isotropic and anisotropic decays. Pump intensities in the order of 10(11) photons x pulse(-1) x cm(-2) were required to obtain annihilation-free conditions. The most important consequence of applied very low excitation doses is an observation of a subpicosecond process within the BChl e manifold (approximately 200-500 fs), manifesting itself as a rise in the red part of the Q(y) absorption band of the BChl e aggregates. The subsequent decay of the kinetics measured in the BChl e region and the corresponding rise in the baseplate BChl a is not single-exponential, and at least two components are necessary to fit the data, corresponding to several BChl e-->BChl a transfer steps. Under annihilation-free conditions, the anisotropic kinetics show a generally slow decay within the BChl e band (10-20 ps) whereas it decays more rapidly in the BChl a region ( approximately 1 ps). Analysis of the experimental data gives a detailed picture of the overall time evolution of the energy relaxation and energy transfer processes within the chlorosome. The results are interpreted within an exciton model based on the proposed structure.
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Affiliation(s)
- Jakub Psencík
- Department of Chemistry, Biophysical Chemistry, Umeå University, S-901 87 Umeå, Sweden.
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13
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Georgakopoulou S, Cogdell RJ, van Grondelle R, van Amerongen H. Linear-Dichroism Measurements on the LH2 Antenna Complex of Rhodopseudomonas Acidophila Strain 10050 Show that the Transition Dipole Moment of the Carotenoid Rhodopin Glucoside Is Not Collinear with the Long Molecular Axis. J Phys Chem B 2002. [DOI: 10.1021/jp026338s] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sofia Georgakopoulou
- 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, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G128QQ, United Kingdom, and Laboratory of Biophysics, Department of Agrotechnology and Food Sciences, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Richard J. Cogdell
- 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, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G128QQ, United Kingdom, and Laboratory of Biophysics, Department of Agrotechnology and Food Sciences, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Rienk van Grondelle
- 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, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G128QQ, United Kingdom, and Laboratory of Biophysics, Department of Agrotechnology and Food Sciences, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Herbert van Amerongen
- 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, Division of Biochemistry and Molecular Biology, Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G128QQ, United Kingdom, and Laboratory of Biophysics, Department of Agrotechnology and Food Sciences, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
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Wendling M, Przyjalgowski MA, Gülen D, Vulto SIE, Aartsma TJ, van Grondelle R, van Amerongen H. The quantitative relationship between structure and polarized spectroscopy in the FMO complex of Prosthecochloris aestuarii: refining experiments and simulations. PHOTOSYNTHESIS RESEARCH 2002; 71:99-123. [PMID: 16228505 DOI: 10.1023/a:1014947732165] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
New absorption, linear dichroism (LD) and circular dichroism (CD) measurements at low temperatures on the Fenna-Matthews-Olson complex from Prosthecochloris aestuarii are presented. Furthermore, the anisotropy of fluorescence excitation spectra is measured and used to determine absolute LD spectra, i.e. corrected for the degree of orientation of the sample. In contrast to previous studies, this allows comparison of not only the shape but also the amplitude of the measured spectra with that calculated by means of an exciton model. In the exciton model, the point-dipole approximation is used and the calculations are based on the trimeric structure of the complex. An improved description of the absorption and LD spectra by means of the exciton model is obtained by simply using the same site energies and coupling strengths that were given by Louwe et al. (1997, J Phys Chem B 101: 11280-11287) and including three broadening mechanisms, which proved to be essential: Inhomogeneous broadening in a Monte Carlo approach, homogeneous broadening by using the homogeneous line shape determined by fluorescence line-narrowing measurements [Wendling et al. (2000) J Phys Chem B 104: 5825-5831] and lifetime broadening. An even better description is obtained when the parameters are optimized by a global fit of the absorption, LD and CD spectra. New site energies and coupling strengths are estimated. The amplitude of the LD spectrum is described quite well. The shape of the CD spectrum is modelled in a satisfactory way but its size can only be simulated by using a rather large value for the index of refraction of the medium surrounding the chromophores. It is shown that the estimated coupling strengths are compatible with the value of the dipole strength of bacteriochlorophyll a, when using the empty-cavity model for the local-field correction factor.
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Affiliation(s)
- Markus Wendling
- Division of Physics and Astronomy, Department of Biophysics and Physics of Complex Systems, Vrije Universiteit, Faculty of Sciences, De Boelelaan, 1081, 1081 HV, Amsterdam, The Netherlands,
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van Grondelle R, Novoderezhkin V. Dynamics of excitation energy transfer in the LH1 and LH2 light-harvesting complexes of photosynthetic bacteria. Biochemistry 2001; 40:15057-68. [PMID: 11735388 DOI: 10.1021/bi011398u] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Photosynthetic light harvesting is a unique life process that occurs with amazing efficiency. Since the discovery of the structure of the bacterial peripheral light-harvesting complex (LH2), this process has been studied using a variety of advanced laser spectroscopic methods. We are now in a position to discuss the physical origins of excitation energy transfer and trapping in the LH2 and LH1 antennae of photosynthetic purple bacteria. We demonstrate that the time evolution of the state created by the light is determined by the combined action of excitonic pigment-pitment interactions, energetic disorder, and coupling to nuclear motion in a pigment-protein complex. A quantitative fit of experimental data using Redfield theory allowed us to determine the pathways and time scales of exciton and vibrational relaxation and analyze separately different contributions to the measured transient absorption dynamics. Furthermore, these dynamics were observed to be strongly dependent on the excitation wavelength. A numerical fit of this dependence turns out to be extremely critical to a variation of the structure and disorder parameters and, therefore, can be used as a test for different antenna models (disordered ring, elliptical deformations, correlated disorder, etc.). The calculated equilibration dynamics in the exciton basis allow a visualization of the exciton motion using a density matrix picture in real space.
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Affiliation(s)
- R van Grondelle
- Department of Biophysics and Physics of Complex Systems, Faculty of Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands.
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16
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Martyìski T, Frąckowiak D, Miyake J, Dudkowiak A, Piechowiak A. The orientation of bacteriochlorophyll c in green bacteria cells and cell fragments. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1998. [DOI: 10.1016/s1011-1344(98)00123-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Monshouwer R, Abrahamsson M, van Mourik F, van Grondelle R. Superradiance and Exciton Delocalization in Bacterial Photosynthetic Light-Harvesting Systems. J Phys Chem B 1997. [DOI: 10.1021/jp963377t] [Citation(s) in RCA: 333] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- René Monshouwer
- Department of Biophysics, Faculty of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Malin Abrahamsson
- Department of Biophysics, Faculty of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Frank van Mourik
- Department of Biophysics, Faculty of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Rienk van Grondelle
- Department of Biophysics, Faculty of Physics and Astronomy, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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18
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Gülen D, van Grondelle R, van Amerongen H. Structural Information on the Light-Harvesting Complex II of Green Plants That Can Be Deciphered from Polarized Absorption Characteristics. J Phys Chem B 1997. [DOI: 10.1021/jp963364f] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Demet Gülen
- Physics Department, Middle East Technical University, Ankara, 06531, Turkey, and Department of Physics and Astronomy and Institute for Molecular Biological Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Rienk van Grondelle
- Physics Department, Middle East Technical University, Ankara, 06531, Turkey, and Department of Physics and Astronomy and Institute for Molecular Biological Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
| | - Herbert van Amerongen
- Physics Department, Middle East Technical University, Ankara, 06531, Turkey, and Department of Physics and Astronomy and Institute for Molecular Biological Sciences, Vrije Universiteit, De Boelelaan 1081, 1081 HV Amsterdam, The Netherlands
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19
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Alden RG, Johnson E, Nagarajan V, Parson WW, Law CJ, Cogdell RG. Calculations of Spectroscopic Properties of the LH2 Bacteriochlorophyll−Protein Antenna Complex from Rhodopseudomonas acidophila. J Phys Chem B 1997. [DOI: 10.1021/jp970005r] [Citation(s) in RCA: 229] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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20
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Somsen OJ, van Grondelle R, van Amerongen H. Spectral broadening of interacting pigments: polarized absorption by photosynthetic proteins. Biophys J 1996; 71:1934-51. [PMID: 8889168 PMCID: PMC1233660 DOI: 10.1016/s0006-3495(96)79392-x] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Excitonic interaction between pigment molecules is largely responsible for the static and dynamic spectroscopic properties of photosynthetic pigment-proteins. This paper provides a new description of its effect on polarized absorption spectroscopy, in particular on circular dichroism (CD). We investigate excitonic spectra of finite width and use "spectral moments" to compare 1) inhomogeneously broadened excitonic spectra, 2) spectra that are (homogeneously broadened by vibrations or electron-phonon interaction, and 3) spectra that are simulated by applying convolution after the interaction has been evaluated. Two cases are distinguished. If the excitonic splitting is smaller than the width of the interacting absorption bands, the broadening of the excitonic spectrum can be approximated by a convolution approach, although a correction is necessary for CD spectra. If the excitonic splitting exceeds the bandwidth, the well-known exchange narrowing occurs. We demonstrate that this is accompanied by redistribution of dipole strength and spectral shifts. The magnitude of a CD spectrum is conveniently expressed by its first spectral moment. As will be shown, this is independent of spectral broadening as well as dispersive shifts induced by pigment-protein interactions. Consequently, it provides a simple tool to relate the experimental CD spectrum of a pigment complex to the excitonic interactions from which it originates. To illustrate the potential of the presented framework, the spectroscopy of the LH2 pigment-protein complex from purple bacteria is analyzed and compared for dimer-like and ring-like structures. Furthermore, it is demonstrated that the variability of the CD of chlorosomes from green bacteria can be explained by small changes in the structure of their cylindrical bacteriochlorophyll c subunits.
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Affiliation(s)
- O J Somsen
- Department of Physics and Astronomy, Free University Amsterdam, The Netherlands
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Excitations and excitons in bacterial light-harvesting complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1996. [DOI: 10.1016/0005-2728(96)00052-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Cherepy NJ, Du M, Holzwarth AR, Mathies RA. Near-Infrared Resonance Raman Spectra of Chlorosomes: Probing Nuclear Coupling in Electronic Energy Transfer. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp952992e] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nerine J. Cherepy
- Department of Chemistry, University of California, Berkeley, California 94720, and The Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - Mei Du
- Department of Chemistry, University of California, Berkeley, California 94720, and The Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - Alfred R. Holzwarth
- Department of Chemistry, University of California, Berkeley, California 94720, and The Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim a.d. Ruhr, Germany
| | - Richard A. Mathies
- Department of Chemistry, University of California, Berkeley, California 94720, and The Max-Planck-Institut für Strahlenchemie, Stiftstrasse 34-36, D-45470 Mülheim a.d. Ruhr, Germany
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Ma YZ, Cox RP, Gillbro T, Miller M. Bacteriochlorophyll organization and energy transfer kinetics in chlorosomes from Chloroflexus aurantiacus depend on the light regime during growth. PHOTOSYNTHESIS RESEARCH 1996; 47:157-165. [PMID: 24301823 DOI: 10.1007/bf00016178] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/1995] [Accepted: 12/06/1995] [Indexed: 06/02/2023]
Abstract
We have used measurements of fluorescence and circular dichroism (CD) to compare chlorosome-membrane preparations derived from the green filamentous bacterium Chloroflexus aurantiacus grown in continuous culture at two different light-intensities. The cells grown under low light (6 μmol m(-2) s(-1)) had a higher ratio of bacteriochlorophyll (BChl) c to BChl a than cells grown at a tenfold higher light intensity; the high-light-grown cells had much more carotenoid per bacteriochlorophyll.The anisotropy of the QY band of BChl c was calculated from steady-state fluorescence excitation and emission spectra with polarized light. The results showed that the BChl c in the chlorosomes derived from cells grown under high light has a higher structural order than BChl c in chlorosomes from low-light-grown cells. In the central part of the BChl c fluorescence emission band, the average angles between the transition dipole moments for BChl c molecules and the symmetry axis of the chlorosome rod element were estimated as 25° and 17° in chlorosomes obtained from the low- and high-light-grown cells, respectively.This difference in BChl organization was confirmed by the decay associated spectra of the two samples obtained using picosecond single-photon-counting experiments and global analysis of the fluorescence decays. The shortest decay component obtained, which probably represents energy-transfer from the chlorosome bacteriochlorophylls to the BChl a in the baseplate, was 15 ps in the chlorosomes from high-light-grown cell but only 7 ps in the preparation from low-light grown cells. The CD spectra of the two preparations were very different: chlorosomes from low-light-grown cells had a type II spectrum, while those from high-light-grown cells was of type I (Griebenow et al. (1991) Biochim Biophys Acta 1058: 194-202). The different shapes of the CD spectra confirm the existence of a qualitatively different organization of the BChl c in the two types of chlorosome.
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Affiliation(s)
- Y Z Ma
- Department of Physical Chemistry, Umeå University, S-901 87, Umeå, Sweden
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Zhu Y, Ramakrishna B, van Noort PI, Blankenship RE. Microscopic and spectroscopic studies of untreated and hexanol-treated chlorosomes from Chloroflexus aurantiacus. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1995. [DOI: 10.1016/0005-2728(95)00118-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Affiliation(s)
- H van Amerongen
- Department of Physics and Astronomy, Free University of Amsterdam, The Netherlands
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Bloemendal M, van Grondelle R. Linear-dichroism spectroscopy for the study of structural properties of proteins. Mol Biol Rep 1993; 18:49-69. [PMID: 8232293 DOI: 10.1007/bf01006895] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This review gives an experiment directed survey of the application of linear-dichroism (LD) spectroscopy to the study of proteins. LD spectroscopy is a relatively simple technique that provides information on the orientation of chromophores in molecules, on molecular characteristics such as shape, size and electronic properties, and on binding parameters in molecular complexes. Since LD is only observed when the molecules are non-randomly oriented in the sample, particular attention is paid to various orientation techniques, viz. in electric and flow fields, in polymer films and gels, and by light induction (photoselection). Examples are given on bacteriorhodopsin and retinals, chlorosomes, lens crystallins, aspartate aminotransferase, and the interaction of gene32- and recA-protein with DNA.
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Affiliation(s)
- M Bloemendal
- Department of Protein and Molecular Biology, Royal Free Hospital School of Medicine, London, UK
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