1
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Drosou M, Bhattacharjee S, Pantazis DA. Combined Multireference-Multiscale Approach to the Description of Photosynthetic Reaction Centers. J Chem Theory Comput 2024. [PMID: 39116215 DOI: 10.1021/acs.jctc.4c00578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2024]
Abstract
A first-principles description of the primary photochemical processes that drive photosynthesis and sustain life on our planet remains one of the grand challenges of modern science. Recent research established that explicit incorporation of protein electrostatics in excited-state calculations of photosynthetic pigments, achieved for example with quantum-mechanics/molecular-mechanics (QM/MM) approaches, is essential for a meaningful description of the properties and function of pigment-protein complexes. Although time-dependent density functional theory has been used productively so far in QM/MM approaches for the study of such systems, this methodology has limitations. Here we pursue for the first time a QM/MM description of the reaction center in the principal enzyme of oxygenic photosynthesis, Photosystem II, using multireference wave function theory for the high-level QM region. We identify best practices and establish guidelines regarding the rational choice of active space and appropriate state-averaging for the efficient and reliable use of complete active space self-consistent field (CASSCF) and the N-electron valence state perturbation theory (NEVPT2) in the prediction of low-lying excited states of chlorophyll and pheophytin pigments. Given that the Gouterman orbitals are inadequate as a minimal active space, we define specific minimal and extended active spaces for the NEVPT2 description of electronic states that fall within the Q and B bands. Subsequently, we apply our multireference-QM/MM protocol to the description of all pigments in the reaction center of Photosystem II. The calculations reproduce the electrochromic shifts induced by the protein matrix and the ordering of site energies consistent with the identity of the primary donor (ChlD1) and the experimentally known asymmetric and directional electron transfer. The optimized protocol sets the stage for future multireference treatments of multiple pigments, and hence for multireference studies of charge separation, while it is transferable to the study of any photoactive embedded tetrapyrrole system.
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Affiliation(s)
- Maria Drosou
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Sinjini Bhattacharjee
- 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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2
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Cherepanov DA, Milanovsky GE, Neverov KV, Obukhov YN, Maleeva YV, Aybush AV, Kritsky MS, Nadtochenko VA. Exciton interactions of chlorophyll tetramer in water-soluble chlorophyll-binding protein BoWSCP. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 309:123847. [PMID: 38217986 DOI: 10.1016/j.saa.2024.123847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 01/02/2024] [Accepted: 01/03/2024] [Indexed: 01/15/2024]
Abstract
The exciton interaction of four chlorophyll a (Chl a) molecules in a symmetrical tetrameric complex of the water-soluble chlorophyll-binding protein BoWSCP was analyzed in the pH range of 3-11. Exciton splitting ΔE = 232 ± 2 cm-1 of the Qy band of Chl a into two subcomponents with relative intensities of 78.1 ± 0.7 % and 21.9 ± 0.7 % was determined by a joint decomposition of the absorption and circular dichroism spectra into Gaussian functions. The exciton coupling parameters were calculated based on the BoWSCP atomic structure in three approximations: the point dipole model, the distributed atomic monopoles, and direct ab initio calculations in the TDDFT/PCM approximation. The Coulomb interactions of monomers were calculated within the continuum model using three values of optical permittivity. The models based on the properties of free Chl a in solution suffer from significant errors both in estimating the absolute value of the exciton interaction and in the relative intensity of exciton transitions. Calculations within the TDDFT/PCM approximation reproduce the experimentally determined parameters of the exciton splitting and the relative intensities of the exciton bands. The following factors of pigment-protein and pigment-pigment interactions were examined: deviation of the macrocycle geometry from the planar conformation of free Chl; the formation of hydrogen bonds between the macrocycle and water molecules; the overlap of wave functions of monomers at close distances. The most significant factor is the geometrical deformation of the porphyrin macrocycle, which leads to an increase in the dipole moment of Chl monomer from 5.5 to 6.9 D and to a rotation of the dipole moment by 15° towards the cyclopentane ring. The contributions of resonant charge-transfer states to the wave functions of the Chl dimer were determined and the transition dipole moments of the symmetric and antisymmetric charge-transfer states were estimated.
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Affiliation(s)
- D A Cherepanov
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Kosygina str., 4, Russian Federation; A.N. Belozersky Institute Of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Leninskye gory, 1b.40, Russian Federation.
| | - G E Milanovsky
- A.N. Belozersky Institute Of Physico-Chemical Biology, Moscow State University, 119992 Moscow, Leninskye gory, 1b.40, Russian Federation
| | - K V Neverov
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences", 119071 Moscow, Leninsky prospect, 33b.2, Russian Federation; Faculty of Biology, Moscow State University, 119234 Moscow, Leninskye gory, 1b.12, Russian Federation
| | - Yu N Obukhov
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences", 119071 Moscow, Leninsky prospect, 33b.2, Russian Federation
| | - Yu V Maleeva
- Faculty of Biology, Moscow State University, 119234 Moscow, Leninskye gory, 1b.12, Russian Federation
| | - A V Aybush
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Kosygina str., 4, Russian Federation
| | - M S Kritsky
- A.N. Bach Institute of Biochemistry, Federal Research Center "Fundamentals of Biotechnology", Russian Academy of Sciences", 119071 Moscow, Leninsky prospect, 33b.2, Russian Federation
| | - V A Nadtochenko
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 119991 Moscow, Kosygina str., 4, Russian Federation; Department of Chemistry, Moscow State University, 119991 Moscow, Leninskye gory, 1b.3, Russian Federation
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3
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Sirohiwal A, Pantazis DA. Reaction Center Excitation in Photosystem II: From Multiscale Modeling to Functional Principles. Acc Chem Res 2023; 56:2921-2932. [PMID: 37844298 PMCID: PMC10634305 DOI: 10.1021/acs.accounts.3c00392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Indexed: 10/18/2023]
Abstract
Oxygenic photosynthesis is the fundamental energy-converting process that utilizes sunlight to generate molecular oxygen and the organic compounds that sustain life. Protein-pigment complexes harvest light and transfer excitation energy to specialized pigment assemblies, reaction centers (RC), where electron transfer cascades are initiated. A molecular-level understanding of the primary events is indispensable for elucidating the principles of natural photosynthesis and enabling development of bioinspired technologies. The primary enzyme in oxygenic photosynthesis is Photosystem II (PSII), a membrane-embedded multisubunit complex, that catalyzes the light-driven oxidation of water. The RC of PSII consists of four chlorophyll a and two pheophytin a pigments symmetrically arranged along two core polypeptides; only one branch participates in electron transfer. Despite decades of research, fundamental questions remain, including the origin of this functional asymmetry, the nature of primary charge-transfer states and the identity of the initial electron donor, the origin of the capability of PSII to enact charge separation with far-red photons, i.e., beyond the "red limit" where individual chlorophylls absorb, and the role of protein conformational dynamics in modulating charge-separation pathways.In this Account, we highlight developments in quantum-chemistry based excited-state computations for multipigment assemblies and the refinement of protocols for computing protein-induced electrochromic shifts and charge-transfer excitations calibrated with modern local correlation coupled cluster methods. We emphasize the importance of multiscale atomistic quantum-mechanics/molecular-mechanics and large-scale molecular dynamics simulations, which enabled direct and accurate modeling of primary processes in RC excitation at the quantum mechanical level.Our findings show how differential protein electrostatics enable spectral tuning of RC pigments and generate functional asymmetry in PSII. A chlorophyll pigment on the active branch (ChlD1) has the lowest site energy in PSII and is the primary electron donor. The complete absence of low-lying charge-transfer states within the central pair of chlorophylls excludes a long-held assumption about the initial charge separation. Instead, we identify two primary charge separation pathways, both with the same pheophytin acceptor (PheoD1): a fast pathway with ChlD1 as the primary electron donor (short-range charge-separation) and a slow pathway with PD1PD2 as the initial donor (long-range charge separation). The low-energy spectrum is dominated by two states with significant charge-transfer character, ChlD1δ+PheoD1δ- and PD1δ+PheoD1δ-. The conformational dynamics of PSII allows these charge-transfer states to span wide energy ranges, pushing oxygenic photosynthesis beyond the "red limit". These results provide a quantum mechanical picture of the primary events in the RC of oxygenic photosynthesis, forming a solid basis for interpreting experimental observations and for extending photosynthesis research in new directions.
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Affiliation(s)
- Abhishek Sirohiwal
- Department
of Biochemistry and Biophysics, Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden
| | - Dimitrios A. Pantazis
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
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4
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Ozaydin B, Curutchet C. Unraveling the role of thermal fluctuations on the exciton structure of the cryptophyte PC612 and PC645 photosynthetic antenna complexes. Front Mol Biosci 2023; 10:1268278. [PMID: 37790875 PMCID: PMC10544999 DOI: 10.3389/fmolb.2023.1268278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 08/30/2023] [Indexed: 10/05/2023] Open
Abstract
Protein scaffolds play a crucial role in tuning the light harvesting properties of photosynthetic pigment-protein complexes, influencing pigment-protein and pigment-pigment excitonic interactions. Here, we investigate the influence of thermal dynamic effects on the protein tuning mechanisms of phycocyanin PC645 and PC612 antenna complexes of cryptophyte algae, featuring closed or open quaternary structures. We employ a dual molecular dynamics (MD) strategy that combines extensive classical MD simulations with multiple short Born-Oppenheimer quantum/molecular mechanical (QM/MM) simulations to accurately account for both static and dynamic disorder effects. Additionally, we compare the results with an alternative protocol based on multiple QM/MM geometry optimizations of the pigments. Subsequently, we employ polarizable QM/MM calculations using time-dependent density functional theory (TD-DFT) to compute the excited states, and we adopt the full cumulant expansion (FCE) formalism to describe the absorption and circular dichroism spectra. Our findings indicate that thermal effects have only minor impacts on the energy ladder in PC612, despite its remarkable flexibility owing to an open quaternary structure. In striking contrast, thermal effects significantly influence the properties of PC645 due to the absence of a hydrogen bond controlling the twist of ring D in PCB β82 bilins, as well as the larger impact of fluctuations on the excited states of MBV pigments, which possess a higher conjugation length compared to other bilin types. Overall, the dual MD protocol combined with the FCE formalism yields excellent spectral properties for PC612 and PC645, and the resultant excitonic Hamiltonians pave the way for future investigations concerning the implications of open and closed quaternary structures on phycocyanin light harvesting properties.
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Affiliation(s)
- Beste Ozaydin
- Departament de Farmàcia i Tecnologia Farmacèutica, i Fisicoquímica, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona (UB), Barcelona, Spain
- Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona (UB), Barcelona, Spain
| | - Carles Curutchet
- Departament de Farmàcia i Tecnologia Farmacèutica, i Fisicoquímica, Facultat de Farmàcia i Ciències de l’Alimentació, Universitat de Barcelona (UB), Barcelona, Spain
- Institut de Química Teòrica i Computacional (IQTCUB), Universitat de Barcelona (UB), Barcelona, Spain
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5
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Brütting M, Foerster JM, Kümmel S. Understanding Primary Charge Separation in the Heliobacterial Reaction Center. J Phys Chem Lett 2023; 14:3092-3102. [PMID: 36951395 DOI: 10.1021/acs.jpclett.3c00377] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The homodimeric reaction center of heliobacteria retains features of the ancestral reaction center and can thus provide insights into the evolution of photosynthesis. Primary charge separation is expected to proceed in a two-step mechanism along either of the two reaction center branches. We reveal the first charge-separation step from first-principles calculations based on time-dependent density functional theory with an optimally tuned range-separated hybrid and ab initio Born-Oppenheimer molecular dynamics: the electron is most likely localized on the electron transfer cofactor 3 (EC3, OH-chlorophyll a), and the hole on the adjacent EC2. Including substantial parts of the surrounding protein environment into the calculations shows that a distinct structural mechanism is decisive for the relative energetic positioning of the electronic excitations: specific charged amino acids in the vicinity of EC3 lower the energy of charge-transfer excitations and thus facilitate efficient charge separation. These results are discussed considering recent experimental insights.
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Macernis M, Streckaite S, Litvin R, Pascal AA, Llansola-Portoles MJ, Robert B, Valkunas L. Electronic and Vibrational Properties of Allene Carotenoids. J Phys Chem A 2022; 126:813-824. [PMID: 35114087 PMCID: PMC8859822 DOI: 10.1021/acs.jpca.1c09393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Carotenoids are conjugated
linear molecules built from the repetition
of terpene units, which display a large structural diversity in nature.
They may, in particular, contain several types of side or end groups,
which tune their functional properties, such as absorption position
and photochemistry. We report here a detailed experimental study of
the absorption and vibrational properties of allene-containing carotenoids,
together with an extensive modeling of these experimental data. Our
calculations can satisfactorily explain the electronic properties
of vaucheriaxanthin, where the allene group introduces the equivalent
of one C=C double bond into the conjugated C=C chain.
The position of the electronic absorption of fucoxanthin and butanoyloxyfucoxanthin
requires long-range corrections to be found correctly on the red side
of that of vaucheriaxanthin; however, these corrections tend to overestimate
the effect of the conjugated and nonconjugated C=O groups in
these molecules. We show that the resonance Raman spectra of these
carotenoids are largely perturbed by the presence of the allene group,
with the two major Raman contributions split into two components.
These perturbations are satisfactorily explained by modeling, through
a gain in the Raman intensity of the C=C antisymmetric stretching
mode, induced by the presence of the allene group in the carotenoid
C=C chain.
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Affiliation(s)
- Mindaugas Macernis
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio Avenue 3, LT-10222 Vilnius, Lithuania
| | - Simona Streckaite
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Radek Litvin
- Biology Centre, Czech Academy of Sciences, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic
| | - Andrew A Pascal
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Manuel J Llansola-Portoles
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Bruno Robert
- Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Saclay, 91198 Gif-sur-Yvette, France
| | - Leonas Valkunas
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio Avenue 3, LT-10222 Vilnius, Lithuania.,Molecular Compounds Physics Department, Center for Physical Sciences and Technology, Sauletekio Avenue 3, LT-10257 Vilnius, Lithuania
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7
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Llansola-Portoles MJ, Pascal AA, Robert B. Resonance Raman: A powerful tool to interrogate carotenoids in biological matrices. Methods Enzymol 2022; 674:113-135. [DOI: 10.1016/bs.mie.2022.03.068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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8
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Lokstein H, Renger G, Götze JP. Photosynthetic Light-Harvesting (Antenna) Complexes-Structures and Functions. Molecules 2021; 26:molecules26113378. [PMID: 34204994 PMCID: PMC8199901 DOI: 10.3390/molecules26113378] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 02/07/2023] Open
Abstract
Chlorophylls and bacteriochlorophylls, together with carotenoids, serve, noncovalently bound to specific apoproteins, as principal light-harvesting and energy-transforming pigments in photosynthetic organisms. In recent years, enormous progress has been achieved in the elucidation of structures and functions of light-harvesting (antenna) complexes, photosynthetic reaction centers and even entire photosystems. It is becoming increasingly clear that light-harvesting complexes not only serve to enlarge the absorption cross sections of the respective reaction centers but are vitally important in short- and long-term adaptation of the photosynthetic apparatus and regulation of the energy-transforming processes in response to external and internal conditions. Thus, the wide variety of structural diversity in photosynthetic antenna “designs” becomes conceivable. It is, however, common for LHCs to form trimeric (or multiples thereof) structures. We propose a simple, tentative explanation of the trimer issue, based on the 2D world created by photosynthetic membrane systems.
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Affiliation(s)
- Heiko Lokstein
- Department of Chemical Physics and Optics, Charles University, Ke Karlovu 3, 12116 Prague, Czech Republic
- Correspondence:
| | - Gernot Renger
- Max-Volmer-Laboratorium, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, Germany
| | - Jan P. Götze
- Institut für Chemie und Biochemie, Freie Universität Berlin, Arnimallee 22, D-14195 Berlin, Germany;
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9
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Sirohiwal A, Neese F, Pantazis DA. How Can We Predict Accurate Electrochromic Shifts for Biochromophores? A Case Study on the Photosynthetic Reaction Center. J Chem Theory Comput 2021; 17:1858-1873. [PMID: 33566610 PMCID: PMC8023663 DOI: 10.1021/acs.jctc.0c01152] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Indexed: 01/28/2023]
Abstract
Protein-embedded chromophores are responsible for light harvesting, excitation energy transfer, and charge separation in photosynthesis. A critical part of the photosynthetic apparatus are reaction centers (RCs), which comprise groups of (bacterio)chlorophyll and (bacterio)pheophytin molecules that transform the excitation energy derived from light absorption into charge separation. The lowest excitation energies of individual pigments (site energies) are key for understanding photosynthetic systems, and form a prime target for quantum chemistry. A major theoretical challenge is to accurately describe the electrochromic (Stark) shifts in site energies produced by the inhomogeneous electric field of the protein matrix. Here, we present large-scale quantum mechanics/molecular mechanics calculations of electrochromic shifts for the RC chromophores of photosystem II (PSII) using various quantum chemical methods evaluated against the domain-based local pair natural orbital (DLPNO) implementation of the similarity-transformed equation of motion coupled cluster theory with single and double excitations (STEOM-CCSD). We show that certain range-separated density functionals (ωΒ97, ωΒ97X-V, ωΒ2PLYP, and LC-BLYP) correctly reproduce RC site energy shifts with time-dependent density functional theory (TD-DFT). The popular CAM-B3LYP functional underestimates the shifts and is not recommended. Global hybrid functionals are too insensitive to the environment and should be avoided, while nonhybrid functionals are strictly nonapplicable. Among the applicable approximate coupled cluster methods, the canonical versions of CC2 and ADC(2) were found to deviate significantly from the reference results both for the description of the lowest excited state and for the electrochromic shifts. By contrast, their spin-component-scaled (SCS) and particularly the scale-opposite-spin (SOS) variants compare well with the reference DLPNO-STEOM-CCSD and the best range-separated DFT methods. The emergence of RC excitation asymmetry is discussed in terms of intrinsic and protein electrostatic potentials. In addition, we evaluate a minimal structural scaffold of PSII, the D1-D2-CytB559 RC complex often employed in experimental studies, and show that it would have the same site energy distribution of RC chromophores as the full PSII supercomplex, but only under the unlikely conditions that the core protein organization and cofactor arrangement remain identical to those of the intact enzyme.
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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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10
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Sirohiwal A, Neese F, Pantazis DA. Protein Matrix Control of Reaction Center Excitation in Photosystem II. J Am Chem Soc 2020; 142:18174-18190. [PMID: 33034453 PMCID: PMC7582616 DOI: 10.1021/jacs.0c08526] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Indexed: 02/06/2023]
Abstract
Photosystem II (PSII) is a multisubunit pigment-protein complex that uses light-induced charge separation to power oxygenic photosynthesis. Its reaction center chromophores, where the charge transfer cascade is initiated, are arranged symmetrically along the D1 and D2 core polypeptides and comprise four chlorophyll (PD1, PD2, ChlD1, ChlD2) and two pheophytin molecules (PheoD1 and PheoD2). Evolution favored productive electron transfer only via the D1 branch, with the precise nature of primary excitation and the factors that control asymmetric charge transfer remaining under investigation. Here we present a detailed atomistic description for both. We combine large-scale simulations of membrane-embedded PSII with high-level quantum-mechanics/molecular-mechanics (QM/MM) calculations of individual and coupled reaction center chromophores to describe reaction center excited states. We employ both range-separated time-dependent density functional theory and the recently developed domain based local pair natural orbital (DLPNO) implementation of the similarity transformed equation of motion coupled cluster theory with single and double excitations (STEOM-CCSD), the first coupled cluster QM/MM calculations of the reaction center. We find that the protein matrix is exclusively responsible for both transverse (chlorophylls versus pheophytins) and lateral (D1 versus D2 branch) excitation asymmetry, making ChlD1 the chromophore with the lowest site energy. Multipigment calculations show that the protein matrix renders the ChlD1 → PheoD1 charge-transfer the lowest energy excitation globally within the reaction center, lower than any pigment-centered local excitation. Remarkably, no low-energy charge transfer states are located within the "special pair" PD1-PD2, which is therefore excluded as the site of initial charge separation in PSII. Finally, molecular dynamics simulations suggest that modulation of the electrostatic environment due to protein conformational flexibility enables direct excitation of low-lying charge transfer states by far-red light.
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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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11
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Kehrer J, Richter R, Foerster JM, Schelter I, Kümmel S. Self-interaction correction, electrostatic, and structural influences on time-dependent density functional theory excitations of bacteriochlorophylls from the light-harvesting complex 2. J Chem Phys 2020; 153:144114. [PMID: 33086803 DOI: 10.1063/5.0014938] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
First-principles calculations offer the chance to obtain a microscopic understanding of light-harvesting processes. Time-dependent density functional theory can have the computational efficiency to allow for such calculations. However, the (semi-)local exchange-correlation approximations that are computationally most efficient fail to describe charge-transfer excitations reliably. We here investigate whether the inexpensive average density self-interaction correction (ADSIC) remedies the problem. For the systems that we study, ADSIC is even more prone to the charge-transfer problem than the local density approximation. We further explore the recently reported finding that the electrostatic potential associated with the chromophores' protein environment in the light-harvesting complex 2 beneficially shifts spurious excitations. We find a great sensitivity on the chromophores' atomistic structure in this problem. Geometries obtained from classical molecular dynamics are more strongly affected by the spurious charge-transfer problem than the ones obtained from crystallography or density functional theory. For crystal structure geometries and density-functional theory optimized ones, our calculations confirm that the electrostatic potential shifts the spurious excitations out of the energetic range that is most relevant for electronic coupling.
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Affiliation(s)
- Juliana Kehrer
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Rian Richter
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
| | | | - Ingo Schelter
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
| | - Stephan Kümmel
- Theoretical Physics IV, University of Bayreuth, D-95440 Bayreuth, Germany
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12
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Sirohiwal A, Berraud-Pache R, Neese F, Izsák R, Pantazis DA. Accurate Computation of the Absorption Spectrum of Chlorophyll a with Pair Natural Orbital Coupled Cluster Methods. J Phys Chem B 2020; 124:8761-8771. [PMID: 32930590 PMCID: PMC7584356 DOI: 10.1021/acs.jpcb.0c05761] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
The
ability to accurately compute low-energy excited states of
chlorophylls is critically important for understanding the vital roles
they play in light harvesting, energy transfer, and photosynthetic
charge separation. The challenge for quantum chemical methods arises
both from the intrinsic complexity of the electronic structure problem
and, in the case of biological models, from the need to account for
protein–pigment interactions. In this work, we report electronic
structure calculations of unprecedented accuracy for the low-energy
excited states in the Q and B bands of chlorophyll a. This is achieved by using the newly developed domain-based local
pair natural orbital (DLPNO) implementation of the similarity transformed
equation of motion coupled cluster theory with single and double excitations
(STEOM-CCSD) in combination with sufficiently large and flexible basis
sets. The results of our DLPNO–STEOM-CCSD calculations are
compared with more approximate approaches. The results demonstrate
that, in contrast to time-dependent density functional theory, the
DLPNO–STEOM-CCSD method provides a balanced performance for
both absorption bands. In addition to vertical excitation energies,
we have calculated the vibronic spectrum for the Q and B bands through
a combination of DLPNO–STEOM-CCSD and ground-state density
functional theory frequency calculations. These results serve as a
basis for comparison with gas-phase experiments.
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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
| | - Romain Berraud-Pache
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Róbert Izsák
- 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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13
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Sláma V, Cupellini L, Mennucci B. Exciton properties and optical spectra of light harvesting complex II from a fully atomistic description. Phys Chem Chem Phys 2020; 22:16783-16795. [PMID: 32662461 DOI: 10.1039/d0cp02492a] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We present a fully atomistic simulation of linear optical spectra (absorption, fluorescence and circular dichroism) of the Light Harvesting Complex II (LHCII) trimer using a hybrid approach, which couples a quantum chemical description of the chlorophylls with a classical model for the protein and the external environment (membrane and water). The classical model uses a polarizable Molecular Mechanics force field, thus allowing mutual polarization effects in the calculations of the excitonic properties. The investigation is performed both on the crystal structure and on structures generated by a μs long classical molecular dynamics simulation of the complex within a solvated membrane. The results show that this integrated approach not only provides a good description of the excitonic properties and optical spectra without the need for additional refinements of the excitonic parameters, but it also allows an atomistic investigation of the relative importance of electronic, structural and environment effects in determining the optical spectra.
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Affiliation(s)
- Vladislav Sláma
- Department of Chemistry and Industrial Chemistry, University of Pisa, via G. Moruzzi 13, 56124 Pisa, Italy.
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14
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Streckaite S, Macernis M, Li F, Kuthanová Trsková E, Litvin R, Yang C, Pascal AA, Valkunas L, Robert B, Llansola-Portoles MJ. Modeling Dynamic Conformations of Organic Molecules: Alkyne Carotenoids in Solution. J Phys Chem A 2020; 124:2792-2801. [PMID: 32163283 PMCID: PMC7313542 DOI: 10.1021/acs.jpca.9b11536] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
![]()
Calculating
the spectroscopic properties of complex conjugated
organic molecules in their relaxed state is far from simple. An additional complexity arises for
flexible molecules in solution, where the rotational energy barriers
are low enough so that nonminimum conformations may become dynamically
populated. These metastable conformations quickly relax during the
minimization procedures preliminary to density functional theory calculations,
and so accounting for their contribution to the experimentally observed
properties is problematic. We describe a strategy for stabilizing
these nonminimum conformations in silico, allowing
their properties to be calculated. Diadinoxanthin and alloxanthin
present atypical vibrational properties in solution, indicating the
presence of several conformations. Performing energy calculations in vacuo and polarizable continuum model calculations in
different solvents, we found three different conformations with values
for the δ dihedral angle of the end ring ca. 0, 180, and 90°
with respect to the plane of the conjugated chain. The latter conformation,
a nonglobal minimum, is not stable during the minimization necessary
for modeling its spectroscopic properties. To circumvent this classical
problem, we used a Car–Parinello MD supermolecular approach,
in which diadinoxanthin was solvated by water molecules so that metastable
conformations were stabilized by hydrogen-bonding interactions. We
progressively removed the number of solvating waters to find the minimum
required for this stabilization. This strategy represents the first
modeling of a carotenoid in a distorted conformation and provides
an accurate interpretation of the experimental data.
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Affiliation(s)
- Simona Streckaite
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Mindaugas Macernis
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio Ave. 3, LT-10222 Vilnius, Lithuania
| | - Fei Li
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.,Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, People's Republic of China
| | - Eliška Kuthanová Trsková
- Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic.,Institute of Microbiology, Academy of Sciences of the Czech Republic, 379 81 Třeboň, Czech Republic
| | - Radek Litvin
- Biology Centre, Czech Academy of Sciences, Branisovska 31, 370 05 Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 370 05 Ceske Budejovice, Czech Republic
| | - Chunhong Yang
- Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, 100093 Beijing, People's Republic of China
| | - Andrew A Pascal
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Leonas Valkunas
- Institute of Chemical Physics, Faculty of Physics, Vilnius University, Saulėtekio Ave. 3, LT-10222 Vilnius, Lithuania.,Molecular Compounds Physics Department, Center for Physical Sciences and Technology, Sauletekio Ave. 3, LT-10257 Vilnius, Lithuania
| | - Bruno Robert
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
| | - Manuel J Llansola-Portoles
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France
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15
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Corbella M, Cupellini L, Lipparini F, Scholes GD, Curutchet C. Spectral Variability in Phycocyanin Cryptophyte Antenna Complexes is Controlled by Changes in the α‐Polypeptide Chains. CHEMPHOTOCHEM 2019. [DOI: 10.1002/cptc.201900045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Marina Corbella
- Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry and Institute of Theoretical and Computational Chemistry (IQTC-UB), Faculty of Pharmacy and Food SciencesUniversity of Barcelona Av. Joan XXIII s/n 08028 Barcelona Spain
- Department of ChemistryUppsala University BMC Box 576 Uppsala S-751 23 Sweden
| | - Lorenzo Cupellini
- Dipartimento di Chimica e Chimica IndustrialeUniversity of Pisa Via Risorgimento 35 56126 Pisa Italy
- Institute for Research in Biomedicine (IRB Barcelona)The Barcelona Institute of Science and Technology Baldiri Reixac 10 08028 Barcelona Spain
| | - Filippo Lipparini
- Dipartimento di Chimica e Chimica IndustrialeUniversity of Pisa Via Risorgimento 35 56126 Pisa Italy
| | - Gregory D. Scholes
- Department of ChemistryPrinceton University Washington Road, Princeton New Jersey 08544 United States
| | - Carles Curutchet
- Department of Pharmacy and Pharmaceutical Technology and Physical Chemistry and Institute of Theoretical and Computational Chemistry (IQTC-UB), Faculty of Pharmacy and Food SciencesUniversity of Barcelona Av. Joan XXIII s/n 08028 Barcelona Spain
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16
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Chojecki M, Rutkowska-Zbik D, Korona T. Dimerization Behavior of Methyl Chlorophyllide a as the Model of Chlorophyll a in the Presence of Water Molecules-Theoretical Study. J Chem Inf Model 2019; 59:2123-2140. [PMID: 30998013 DOI: 10.1021/acs.jcim.8b00984] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A dimerization of methyl chlorophyllide a molecules and a role of water in stabilization and properties of methyl chlorophyllide a dimers were studied by means of symmetry-adapted perturbation theory (SAPT), functional-group SAPT (F-SAPT), density-functional theory (DFT), and time-dependent DFT approaches. The quantification of various types of interactions, such as π-π stacking, coordinative, and hydrogen bonding by applying the F-SAPT energy decomposition scheme shows the major role of the magnesium atom and the pheophytin macrocycle in the stability of the complex. The examination of interaction energy components with respect to a mutual orientation of monomers and in the presence or absence of water molecules reveals that the dispersion energy is the main binding factor of the interaction, while water molecules tend to weaken the attraction between methyl chlorophyllide a species. The dimerization can be seen in computed UV-vis spectra, and results in a doubling of the lowest peaks, as compared to the monomer spectrum, and in an intensity rise of the lowest 1.8 and 2.4 eV peaks at a cost of the 3.5 eV peaks for the majority of dimer configurations. The complexation of water has little effect on the peaks' position; however, it affects the overall shape of simulated spectra through changes in peak intensities, which is strongly dependent on the structure of the complex. The VCD spectra for the dimers show several characteristic features attributed to the interaction of substituting groups and/or water ligand attached to macrocycle groups belonging to different monomers. VCD is sensitive to the type of the formed dimer, but not to the number of water molecules it contains. This and several other features, as well as the differential UV-vis spectra, may serve as the indicator of the presence of a given dimer structure in the experiment.
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Affiliation(s)
- Michał Chojecki
- Faculty of Chemistry , University of Warsaw , ul. Pasteura 1 , 02-093 Warsaw , Poland
| | - Dorota Rutkowska-Zbik
- Jerzy Haber Institute of Catalysis and Surface Chemistry , Polish Academy of Sciences , ul. Niezapominajek 8 , 30-239 Cracow , Poland
| | - Tatiana Korona
- Faculty of Chemistry , University of Warsaw , ul. Pasteura 1 , 02-093 Warsaw , Poland
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17
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Xu P, Roy LM, Croce R. Functional organization of photosystem II antenna complexes: CP29 under the spotlight. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:815-822. [DOI: 10.1016/j.bbabio.2017.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 07/28/2017] [Accepted: 07/30/2017] [Indexed: 10/19/2022]
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18
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Fox KF, Balevičius V, Chmeliov J, Valkunas L, Ruban AV, Duffy CDP. The carotenoid pathway: what is important for excitation quenching in plant antenna complexes? Phys Chem Chem Phys 2017; 19:22957-22968. [DOI: 10.1039/c7cp03535g] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Plant light-harvesting is regulated by the Non-Photochemical Quenching (NPQ) mechanism involving the slow trapping of excitation energy by carotenoids in the Photosystem II (PSII) antenna in response to high light.
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Affiliation(s)
- Kieran F. Fox
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London E1 4NS
- UK
| | - Vytautas Balevičius
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London E1 4NS
- UK
| | - Jevgenij Chmeliov
- Department of Theoretical Physics
- Faculty of Physics
- Vilnius University
- Sauletekio Ave. 9
- 10222 Vilnius
| | - Leonas Valkunas
- Department of Theoretical Physics
- Faculty of Physics
- Vilnius University
- Sauletekio Ave. 9
- 10222 Vilnius
| | - Alexander V. Ruban
- School of Biological and Chemical Sciences
- Queen Mary University of London
- London E1 4NS
- UK
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19
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Abstract
The design of optimal light-harvesting (supra)molecular systems and materials is one of the most challenging frontiers of science. Theoretical methods and computational models play a fundamental role in this difficult task, as they allow the establishment of structural blueprints inspired by natural photosynthetic organisms that can be applied to the design of novel artificial light-harvesting devices. Among theoretical strategies, the application of quantum chemical tools represents an important reality that has already reached an evident degree of maturity, although it still has to show its real potentials. This Review presents an overview of the state of the art of this strategy, showing the actual fields of applicability but also indicating its current limitations, which need to be solved in future developments.
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Affiliation(s)
- Carles Curutchet
- Departament de Fisicoquímica, Facultat de Farmàcia, Universitat de Barcelona , Av. Joan XXIII s/n, 08028 Barcelona, Spain
| | - Benedetta Mennucci
- Dipartimento di Chimica e Chimica Industriale, University of Pisa , via G. Moruzzi 13, 56124 Pisa, Italy
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20
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Fox KF, Bricker WP, Lo C, Duffy CDP. Distortions of the Xanthophylls Caused by Interactions with Neighboring Pigments and the LHCII Protein Are Crucial for Studying Energy Transfer Pathways within the Complex. J Phys Chem B 2015; 119:15550-60. [DOI: 10.1021/acs.jpcb.5b08941] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- K. F. Fox
- The
School of Biological and Chemical Sciences, Queen Mary’s University of London, Mile End Road, London E1 4NS, England
| | - William P. Bricker
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, 1 Brookings Drive, Saint Louis, Missouri 63130-4899, United States
| | - Cynthia Lo
- Department
of Energy, Environmental and Chemical Engineering, Washington University in St. Louis, 1 Brookings Drive, Saint Louis, Missouri 63130-4899, United States
| | - C. D. P. Duffy
- The
School of Biological and Chemical Sciences, Queen Mary’s University of London, Mile End Road, London E1 4NS, England
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21
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Geometric description and electronic properties of the principal photosynthetic pigments of higher plants: a DFT study. J Mol Model 2015; 21:256. [PMID: 26369916 DOI: 10.1007/s00894-015-2796-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
The geometric parameters, local and global chemical reactivity parameters (such as the ionization potential, electron affinity, electronegativity, hardness, softness, chemical potential, and electrophilicity index), as well as the energy levels (HOMO/LUMO) and HOMO-LUMO energy gaps have been determined for the principal carotenoids in higher plants. DFT calculations performed using the B3LYP functional in combination with the 6-31G(d,p) (for geometric parameters) and 6-31 + G(d,p) (for energy parameters) basis sets were carried out to study these structures. The HOMO-LUMO energy gaps obtained with the TPSSh functional were compared with the corresponding energy gaps obtained with B3LYP (when both functionals were used with the 6-31 + G(d,p) basis set). Upon analyzing all of the calculated parameters of the studied molecules, both carotenes were found to be the most reactive, followed by β-cryptoxanthin, zeaxanthin, lutein, violaxanthin, and finally neoxanthin, the least reactive molecule. The results reveal that all of the carotenoids show very high coplanarity in the photochemically active region, resulting in small HOMO-LUMO energy gaps. The calculated local and global chemical reactivity parameters indicate that all of the studied molecules may be classified as soft, as they are good electron donors/acceptors, making these molecules good candidates for use in artificial photosynthetic systems.
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22
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Shrestha K, Jakubikova E. Ground-State Electronic Structure of RC-LH1 and LH2 Pigment Assemblies of Purple Bacteria via the EBF-MO Method. J Phys Chem A 2015. [DOI: 10.1021/acs.jpca.5b05644] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kushal Shrestha
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Elena Jakubikova
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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23
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Chmeliov J, Bricker WP, Lo C, Jouin E, Valkunas L, Ruban AV, Duffy CDP. An ‘all pigment’ model of excitation quenching in LHCII. Phys Chem Chem Phys 2015; 17:15857-67. [DOI: 10.1039/c5cp01905b] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
This work presents the first all-pigment microscopic model of a major light-harvesting complex of plants and the first attempt to capture the dissipative character of the known structure.
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Affiliation(s)
- Jevgenij Chmeliov
- Department of Theoretical Physics
- Faculty of Physics
- Vilnius University
- LT-10222 Vilnius
- Lithuania
| | - William P. Bricker
- Department of Energy
- Environmental and Chemical Engineering
- Washington University in St. Louis
- Saint Louis
- USA
| | - Cynthia Lo
- Department of Energy
- Environmental and Chemical Engineering
- Washington University in St. Louis
- Saint Louis
- USA
| | - Elodie Jouin
- The School of Biological and Chemical Sciences
- Queen Mary
- University of London
- London E1 4NS
- UK
| | - Leonas Valkunas
- Department of Theoretical Physics
- Faculty of Physics
- Vilnius University
- LT-10222 Vilnius
- Lithuania
| | - Alexander V. Ruban
- The School of Biological and Chemical Sciences
- Queen Mary
- University of London
- London E1 4NS
- UK
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24
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Macernis M, Galzerano D, Sulskus J, Kish E, Kim YH, Koo S, Valkunas L, Robert B. Resonance Raman spectra of carotenoid molecules: influence of methyl substitutions. J Phys Chem A 2014; 119:56-66. [PMID: 25476500 DOI: 10.1021/jp510426m] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report here the resonance Raman spectra and the quantum chemical calculations of the Raman spectra for β-carotene and 13,13'-diphenyl-β-carotene. The first aim of this approach was to test the robustness of the method used for modeling β-carotene, and assess whether it could accurately predict the vibrational properties of derivatives in which conjugated substituents had been introduced. DFT calculations, using the B3LYP functional in combination with the 6-311G(d,p) basis set, were able to accurately predict the influence of two phenyl substituents connected to the β-carotene molecule, although these deeply perturb the vibrational modes. This experimentally validated modeling technique leads to a fine understanding of the origin of the carotenoid resonance Raman bands, which are widely used for assessing the properties of these molecules, and in particular in complex media, such as binding sites provided by biological macromolecules.
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Affiliation(s)
- Mindaugas Macernis
- Theoretical Physics Department, Faculty of Physics, Vilnius University , Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
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25
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Dreuw A, Faraji S. A quantum chemical perspective on (6-4) photolesion repair by photolyases. Phys Chem Chem Phys 2014; 15:19957-69. [PMID: 24145385 DOI: 10.1039/c3cp53313a] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
(6-4)-Photolyases are fascinating enzymes which repair (6-4)-DNA photolesions utilizing light themselves. It is well known that upon initial photo-excitation of an antenna pigment an electron is transferred from an adjacent FADH(-) cofactor to the photolesion initiating repair, i.e. restoration of the original undamaged DNA bases. Concerning the molecular details of this amazing repair mechanism, the early steps of energy transfer and catalytic electron generation are well understood, the terminal repair mechanism, however, is still a matter of ongoing debate. In this perspective article, recent results of quantum chemical investigations are presented, and their meaning for the repair mechanism under natural conditions is outlined. Consequences of natural light conditions, temperature and thermal equilibration are highlighted when issues like the initial protonation state of the relevant histidines and the lesion, or the direction of electron transfer are discussed.
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Affiliation(s)
- Andreas Dreuw
- Interdisciplinary Center for Scientific Computing, Ruprecht-Karls University, Im Neuenheimer Feld 368, 69120 Heidelberg, Germany.
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26
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Macernis M, Sulskus J, Malickaja S, Robert B, Valkunas L. Resonance Raman Spectra and Electronic Transitions in Carotenoids: A Density Functional Theory Study. J Phys Chem A 2014; 118:1817-25. [DOI: 10.1021/jp406449c] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mindaugas Macernis
- Theoretical
Physics Department, Faculty of Physics, Vilnius University, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
- Center for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius, Lithuania
| | - Juozas Sulskus
- Theoretical
Physics Department, Faculty of Physics, Vilnius University, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
| | - Svetlana Malickaja
- Theoretical
Physics Department, Faculty of Physics, Vilnius University, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
| | - Bruno Robert
- Institut
de Biologie et de Technologie de Saclay, CEA, UMR 8221 CNRS, University Paris Sud, CEA Saclay, 91191 Gif sur Yvette, Paris, France
| | - Leonas Valkunas
- Theoretical
Physics Department, Faculty of Physics, Vilnius University, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania
- Center for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius, Lithuania
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27
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Duffy CDP, Pandit A, Ruban AV. Modeling the NMR signatures associated with the functional conformational switch in the major light-harvesting antenna of photosystem II in higher plants. Phys Chem Chem Phys 2014; 16:5571-80. [PMID: 24513782 DOI: 10.1039/c3cp54971b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The major photosystem II antenna complex, LHCII, possesses an intrinsic conformational switch linked to the formation of a photoprotective, excitation-quenching state. Recent solid state NMR experiments revealed that aggregation-induced quenching in (13)C-enriched LHCII from C. reinhardtii is associated with changes to the chemical shifts of three specific (13)C atoms in the Chla conjugated macrocycle. We performed DFT-based NMR calculations on the strongly-quenched crystal structure of LHCII (taken from spinach). We demonstrate that specific Chla-xanthophyll interactions in the quenched structure lead to changes in the Chla(13)C chemical shifts that are qualitatively similar to those observed by solid state NMR. We propose that these NMR changes are due to modulations in Chla-xanthophyll associations that occur due to a quenching-associated functional conformation change in the lutein and neoxanthin domains of LHCII. The combination of solid-state NMR and theoretical modeling is therefore a powerful tool for assessing functional conformational switching in the photosystem II antenna.
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Affiliation(s)
- Christopher D P Duffy
- The School of Biological and Chemical Science, Queen Mary, University of London, Mile End, London E1 4NS, UK.
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28
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König C, Neugebauer J. Exciton Coupling Mechanisms Analyzed with Subsystem TDDFT: Direct vs Pseudo Exchange Effects. J Phys Chem B 2013; 117:3480-7. [DOI: 10.1021/jp3105419] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Carolin König
- Theoretische Organische
Chemie, Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster,
Germany
| | - Johannes Neugebauer
- Theoretische Organische
Chemie, Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster,
Germany
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29
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Götze JP, Thiel W. TD-DFT and DFT/MRCI study of electronic excitations in Violaxanthin and Zeaxanthin. Chem Phys 2013. [DOI: 10.1016/j.chemphys.2013.01.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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30
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König C, Neugebauer J. Protein Effects on the Optical Spectrum of the Fenna–Matthews–Olson Complex from Fully Quantum Chemical Calculations. J Chem Theory Comput 2013; 9:1808-20. [DOI: 10.1021/ct301111q] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Carolin König
- Theoretische Organische
Chemie, Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster,
Germany
| | - Johannes Neugebauer
- Theoretische Organische
Chemie, Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, Corrensstraße 40, 48149 Münster,
Germany
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31
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Renger T, Müh F. Understanding photosynthetic light-harvesting: a bottom up theoretical approach. Phys Chem Chem Phys 2013; 15:3348-71. [PMID: 23361062 DOI: 10.1039/c3cp43439g] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We discuss a bottom up approach for modeling photosynthetic light-harvesting. Methods are reviewed for a full structure-based parameterization of the Hamiltonian of pigment-protein complexes (PPCs). These parameters comprise (i) the local transition energies of the pigments in their binding sites in the protein, the site energies; (ii) the couplings between optical transitions of the pigments, the excitonic couplings; and (iii) the spectral density characterizing the dynamic modulation of pigment transition energies and excitonic couplings by protein vibrations. Starting with quantum mechanics perturbation theory, we provide a microscopic foundation for the standard PPC Hamiltonian and relate the expressions obtained for its matrix elements to quantities that can be calculated with classical molecular mechanics/electrostatics approaches including the whole PPC in atomic detail and using charge and transition densities obtained with quantum chemical calculations on the isolated building blocks of the PPC. In the second part of this perspective, the Hamiltonian is utilized to describe the quantum dynamics of excitons. Situations are discussed that differ in the relative strength of excitonic and exciton-vibrational coupling. The predictive power of the approaches is demonstrated in application to different PPCs, and challenges for future work are outlined.
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Affiliation(s)
- Thomas Renger
- Institut für Theoretische Physik, Johannes Kepler Universität Linz, Linz, Austria.
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32
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König C, Schlüter N, Neugebauer J. Direct determination of exciton couplings from subsystem time-dependent density-functional theory within the Tamm–Dancoff approximation. J Chem Phys 2013; 138:034104. [DOI: 10.1063/1.4774117] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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33
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Duffy CDP, Chmeliov J, Macernis M, Sulskus J, Valkunas L, Ruban AV. Modeling of Fluorescence Quenching by Lutein in the Plant Light-Harvesting Complex LHCII. J Phys Chem B 2012; 117:10974-86. [DOI: 10.1021/jp3110997] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- C. D. P. Duffy
- The School of Biological and
Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, U.K
| | - J. Chmeliov
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėteko al. 9, LT-10222 Vilnius, Lithuania
- Institute of Physics, Center for Physical Sciences and Technology, Gostauto
11, LT-01108 Vilnius, Lithuania
| | - M. Macernis
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėteko al. 9, LT-10222 Vilnius, Lithuania
- Institute of Physics, Center for Physical Sciences and Technology, Gostauto
11, LT-01108 Vilnius, Lithuania
| | - J. Sulskus
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėteko al. 9, LT-10222 Vilnius, Lithuania
| | - L. Valkunas
- Theoretical Physics Department,
Faculty of Physics, Vilnius University,
Saulėteko al. 9, LT-10222 Vilnius, Lithuania
- Institute of Physics, Center for Physical Sciences and Technology, Gostauto
11, LT-01108 Vilnius, Lithuania
| | - A. V. Ruban
- The School of Biological and
Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, U.K
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34
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Banerjee S, Kröner D, Saalfrank P. Resonance Raman and vibronic absorption spectra with Duschinsky rotation from a time-dependent perspective: Application to β-carotene. J Chem Phys 2012; 137:22A534. [DOI: 10.1063/1.4748147] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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35
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Hsiao YW, Götze JP, Thiel W. The central role of Gln63 for the hydrogen bonding network and UV-visible spectrum of the AppA BLUF domain. J Phys Chem B 2012; 116:8064-73. [PMID: 22694087 DOI: 10.1021/jp3028758] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In blue-light sensing using flavin (BLUF) domains, the side-chain orientation of key residues close to the flavin chromophore is still under debate. We report quantum refinements of the wild-type AppA BLUF protein from Rhodobacter sphaeroides starting from two published X-ray structures (1YRX and 2IYG) with different arrangements of the residues around the chromophore. Quantum refinement uses the same experimental X-ray raw data as conventional refinement, but includes data from quantum mechanics/molecular mechanics (QM/MM) calculations as restraints, which is expected to be more reliable than the normally employed MM data. In addition to quantum refinement, pure QM/MM geometry optimizations are performed for the 1YRX and 2IYG structures and for five models derived therefrom. Vertical excitation energies are computed at the QM(DFT/MRCI)/MM level to assess the resulting structures. The experimental absorption maximum of the dark state of wild-type AppA is well reproduced for structures that contain the Gln63 residue in 1YRX-type orientation. The computed excitation energies are red-shifted for structures with a flipped Gln63 residue in 2IYG-type orientation. The calculated 1YRX- and 2IYG-type hydrogen-bonding networks are discussed in detail, particularly with regard to the orientation of the chromophore and the Gln63, Trp104, and Met106 residues.
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Affiliation(s)
- Ya-Wen Hsiao
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470, Mülheim an der Ruhr, Germany
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36
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Fingerhut BP, Sailer CF, Ammer J, Riedle E, de Vivie-Riedle R. Buildup and Decay of the Optical Absorption in the Ultrafast Photo-Generation and Reaction of Benzhydryl Cations in Solution. J Phys Chem A 2012; 116:11064-74. [DOI: 10.1021/jp300986t] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Benjamin P. Fingerhut
- Department Chemie, Ludwig-Maximilians-Universität (LMU), Butenandt-Strasse 11, 81377 München, Germany
| | - Christian F. Sailer
- Lehrstuhl für BioMolekulare
Optik, Ludwig-Maximilians-Universität (LMU), Oettingenstrasse 67, 80538 München, Germany
| | - Johannes Ammer
- Department Chemie, Ludwig-Maximilians-Universität (LMU), Butenandt-Strasse 11, 81377 München, Germany
| | - Eberhard Riedle
- Lehrstuhl für BioMolekulare
Optik, Ludwig-Maximilians-Universität (LMU), Oettingenstrasse 67, 80538 München, Germany
| | - Regina de Vivie-Riedle
- Department Chemie, Ludwig-Maximilians-Universität (LMU), Butenandt-Strasse 11, 81377 München, Germany
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37
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Duffy CDP, Ruban AV. A Theoretical Investigation of Xanthophyll–Protein Hydrogen Bonding in the Photosystem II Antenna. J Phys Chem B 2012; 116:4310-8. [DOI: 10.1021/jp206179c] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher D. P. Duffy
- School of Biological and
Chemical Sciences, Queen Mary University of London, Mile End Road, London
E1 4NS, United Kingdom
| | - Alexander V. Ruban
- School of Biological and
Chemical Sciences, Queen Mary University of London, Mile End Road, London
E1 4NS, United Kingdom
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38
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Kröner D, Götze JP. Modeling of a violaxanthin-chlorophyll b chromophore pair in its LHCII environment using CAM-B3LYP. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2012; 109:12-9. [PMID: 22306026 DOI: 10.1016/j.jphotobiol.2011.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 11/25/2011] [Accepted: 12/18/2011] [Indexed: 02/04/2023]
Abstract
Collecting energy for photosystem II is facilitated by several pigments, xanthophylls and chlorophylls, embedded in the light harvesting complex II (LHCII). One xanthophyll, violaxanthin (Vio), is loosely bound at a site close to a chlorophyll b (Chl). No final answer has yet been found for the role of this specific xanthophyll. We study the electronic structure of Vio in the presence of Chl and under the influence of the LHCII environment, represented by a point charge field (PCF). We compare the capability of the long range corrected density functional theory (DFT) functional CAM-B3LYP to B3LYP for the modeling of the UV/vis spectrum of the Vio+Chl pair. CAM-B3LYP was reported to allow for a very realistic reproduction of bond length alternation of linear polyenes, which has considerable impact on the carotenoid structure and spectrum. To account for the influence of the LHCII environment, the chromophore geometries are optimized using an ONIOM(DFT/6-31G(d):PM6) scheme. Our calculations show that the energies of the locally excited states are almost unaffected by the presence of the partner chromophore or the PCF. There are, however, indications for excitonic coupling of the Chl Soret band and Vio. We propose that Vio may accept energy from blue-light excited Chl.
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Affiliation(s)
- Dominik Kröner
- Theoretische Chemie, Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam, Germany
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39
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Müh F, Renger T. Refined structure-based simulation of plant light-harvesting complex II: linear optical spectra of trimers and aggregates. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2012; 1817:1446-60. [PMID: 22387396 DOI: 10.1016/j.bbabio.2012.02.016] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 02/09/2012] [Accepted: 02/15/2012] [Indexed: 11/27/2022]
Abstract
Linear optical spectra of solubilized trimers and small lamellar aggregates of the major light-harvesting complex II (LHCII) of higher plants are simulated employing excitonic couplings and site energies of chlorophylls (Chls) computed on the basis of the two crystal structures by a combined quantum chemical/electrostatic approach. A good agreement between simulation and experiment is achieved (except for the circular dichroism in the Chl b region), if vibronic transitions of Chls are taken into account. Site energies are further optimized by refinement fits of optical spectra. The differences between refined and directly calculated values are not significant enough to decide, whether the crystal structures are closer to trimers or aggregates. Changes in the linear dichroism spectrum upon aggregation are related to site energy shifts of Chls b601, b607, a603, a610, and a613, and are interpreted in terms of conformational changes of violaxanthin and the two luteins involving their ionone rings. Chl a610 is the energy sink at 77K in both conformations. An analysis of absorption spectra of trimers perpendicular and parallel to the C(3)-axis (van Amerongen et al. Biophys. J. 67 (1994) 837-847) shows that only Chl a604 close to neoxanthin is significantly reoriented in trimers compared to the crystal structures. Whether this pigment is orientated in aggregates as in the crystal structures, can presently not be determined faithfully. To finally decide about pigment reorientations that could be of relevance for non-photochemical quenching, further polarized absorption and fluorescence measurements of aggregates or detergent-depleted LHCII would be helpful. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial.
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Affiliation(s)
- Frank Müh
- Johannes Kepler Universitat Linz, Linz, Austria.
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40
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Plasser F, Barbatti M, Aquino AJA, Lischka H. Electronically excited states and photodynamics: a continuing challenge. Theor Chem Acc 2012. [DOI: 10.1007/s00214-011-1073-y] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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41
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König C, Neugebauer J. Quantum chemical description of absorption properties and excited-state processes in photosynthetic systems. Chemphyschem 2011; 13:386-425. [PMID: 22287108 DOI: 10.1002/cphc.201100408] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Indexed: 11/07/2022]
Abstract
The theoretical description of the initial steps in photosynthesis has gained increasing importance over the past few years. This is caused by more and more structural data becoming available for light-harvesting complexes and reaction centers which form the basis for atomistic calculations and by the progress made in the development of first-principles methods for excited electronic states of large molecules. In this Review, we discuss the advantages and pitfalls of theoretical methods applicable to photosynthetic pigments. Besides methodological aspects of excited-state electronic-structure methods, studies on chlorophyll-type and carotenoid-like molecules are discussed. We also address the concepts of exciton coupling and excitation-energy transfer (EET) and compare the different theoretical methods for the calculation of EET coupling constants. Applications to photosynthetic light-harvesting complexes and reaction centers based on such models are also analyzed.
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Affiliation(s)
- Carolin König
- Institute for Physical and Theoretical Chemistry, Technical University Braunschweig, Braunschweig, Germany
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42
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König C, Neugebauer J. First-principles calculation of electronic spectra of light-harvesting complex II. Phys Chem Chem Phys 2011; 13:10475-90. [PMID: 21369568 DOI: 10.1039/c0cp02808h] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report on a fully quantum chemical investigation of important structural and environmental effects on the site energies of chlorophyll pigments in green-plant light-harvesting complex II (LHC II). Among the tested factors are technical and structural aspects as well as effects of neighboring residues and exciton couplings in the chlorophyll network. By employing a subsystem time-dependent density functional theory (TDDFT) approach based on the frozen density embedding (FDE) method we are able to determine site energies and electronic couplings separately in a systematic way. This approach allows us to treat much larger systems in a quantum chemical way than would be feasible with a conventional density functional theory. Based on this method, we have simulated a series of mutagenesis experiments to investigate the effect of a lack of one pigment in the chlorophyll network on the excitation properties of the other pigments. From these calculations, we can conclude that conformational changes within the chlorophyll molecules, direct interactions with neighboring residues, and interactions with other chlorophyll pigments can lead to non-negligible changes in excitation energies. All of these factors are important when site energies shall be calculated with high accuracy. Moreover, the redistribution of the oscillator strengths due to exciton coupling has a large impact on the calculated absorption spectra. This indicates that modeling mutagenesis experiments requires us to consider the entire set of chlorophyll molecules in the wild type and in the mutant, rather than just considering the missing chlorophyll pigment. An analysis of the mixing of particular excitations and the coupling elements in the FDEc calculation indicates that some pigments in the chlorophyll network act as bridges which mediate the interaction between other pigments. These bridges are also supported by the calculations on the "mutants" lacking the bridging pigment.
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Affiliation(s)
- Carolin König
- Gorlaeus Laboratories, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
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43
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Nilsson Lill SO. On the dimerization of chlorophyll in photosystem II. Phys Chem Chem Phys 2011; 13:16022-7. [DOI: 10.1039/c1cp21390c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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44
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Duffy CDP, Johnson MP, Macernis M, Valkunas L, Barford W, Ruban AV. A Theoretical Investigation of the Photophysical Consequences of Major Plant Light-Harvesting Complex Aggregation within the Photosynthetic Membrane. J Phys Chem B 2010; 114:15244-53. [DOI: 10.1021/jp106234e] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- C. D. P. Duffy
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom, Vilnius University, Faculty of Physics, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania, and Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - M. P. Johnson
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom, Vilnius University, Faculty of Physics, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania, and Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - M. Macernis
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom, Vilnius University, Faculty of Physics, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania, and Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - L. Valkunas
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom, Vilnius University, Faculty of Physics, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania, and Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - W. Barford
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom, Vilnius University, Faculty of Physics, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania, and Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
| | - A. V. Ruban
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom, Vilnius University, Faculty of Physics, Saulėtekio al. 9, LT-10222 Vilnius, Lithuania, and Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QZ, United Kingdom
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