Excitation Transfer in the Peridinin-Chlorophyll-Protein of Amphidinium carterae

Damjanović, A.; Ritz, Thorsten; Schulten, Klaus

doi:10.1016/s0006-3495(00)76422-8

Cited by 125 publications

(195 citation statements)

References 40 publications

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“…It is important to ask what role Per-614 plays in energy transfer to Chl-a. Several studies, including the present work, have suggested that Per-614 has the strongest interaction with Chl-a (19,21,(24)(25)(26)(27)(28). In the N89L mutant, the large spectral shift of the Per-614 S 0 3S 2 transition (see Fig.…”

Section: Origin Of the Ta Bleaching Signal (Dip): Excitonic Coupling supporting

confidence: 59%

“…S3). This apparent discrepancy can be rationalized if the major energy transfer route is not via the Per S 2 3Chl-a Q x pathway, but by the Per S 1 /ICT3Chl-a Q y route (21,24,36). Although the shape of the broad TA transition associated with the S 1 /ICT state changes to some extent, the lifetime stays roughly the same (see Fig.…”

Section: Origin Of the Ta Bleaching Signal (Dip): Excitonic Coupling mentioning

confidence: 99%

“…1), whose environment has been postulated to result in a dramatic blue shift of its absorption spectrum, leading to less efficient direct energy transfer to Chl-a, compared to that from the other bound Pers (19)(20)(21)(22)(23). Another prominent example is Per-614, which has been assigned the strongest electronic interaction with Chl-a (19,21,(24)(25)(26)(27)(28). This enhanced interaction was identified from transient absorption measurements of the onset of bleaching of a Per absorption band Author contributions: E.H. and H.A.F.…”

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confidence: 99%

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Identification of a single peridinin sensing Chl- a excitation in reconstituted PCP by crystallography and spectroscopy

Schulte

Niedzwiedzki

Birge

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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The peridinin-chlorophyll a-protein (PCP) of dinoflagellates is unique among the large variety of natural photosynthetic lightharvesting systems. In contrast to other chlorophyll protein complexes, the soluble PCP is located in the thylakoid lumen, and the carotenoid pigments outnumber the chlorophylls. The structure of the PCP complex consists of two symmetric domains, each with a central chlorophyll a (Chl-a) surrounded by four peridinin molecules. The protein provides distinctive surroundings for the pigment molecules, and in PCP, the specific environment around each peridinin results in overlapping spectral line shapes, suggestive of different functions within the protein. One particular Per, Per-614, is hypothesized to show the strongest electronic interaction with the central Chl-a. We have performed an in vitro reconstitution of pigments into recombinant PCP apo-protein (RFPCP) and into a mutated protein with an altered environment near Per-614. Steady-state and transient optical spectroscopic experiments comparing the RFPCP complex with the reconstituted mutant protein identify specific amino acid-induced spectral shifts. The spectroscopic assignments are reinforced by a determination of the structures of both RFPCP and the mutant by x-ray crystallography to a resolution better than 1.5 Å. RFPCP and mutated RFPCP are unique in representing crystal structures of in vitro reconstituted light-harvesting pigment-protein complexes.light harvesting ͉ peridinin ͉ protein crystallography ͉ refolding ͉ transient absorption spectroscopy M any naturally occurring light-harvesting pigment-protein complexes use chlorophyll (Chl) to collect incoming photons, and most of these systems rely on carotenoids to supplement light-capture in the spectral region of maximal solar irradiance from 420 to 550 nm. Carotenoids function as energy donors in many different natural antenna systems and operate with an efficiency that ranges from 30% to nearly 100%. Carotenoids also fulfill a crucial photoprotective role that preserves the structural and functional integrity of the photosynthetic apparatus. A detailed knowledge of the controlling features of energy transfer in natural light-harvesting systems is critical for designing efficient artificial mimics (1).Structural determinations of several antenna complexes have lead to theoretical treatments of the photophysical processes undergone by the bound pigments and which control photosynthetic light harvesting (2). An effective approach to explore light-harvesting is mutagenesis of specific residues in conjunction with pigment substitutions or incorporations, as shown for the bacterial LH2 complex (3,4). This approach has also been applied to the membrane-bound light-harvesting complex II (LHCII) from higher plants, for which a robust in vitro reconstitution system has been developed (5). While high-resolution x-ray-derived structures exist for both native LH2 (6-8) and LHCII (9, 10), three-dimensional (3D) crystallization of modified complexes has not been possible, although 2D cry...

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Section: Origin Of the Ta Bleaching Signal (Dip): Excitonic Coupling supporting

confidence: 59%

Section: Origin Of the Ta Bleaching Signal (Dip): Excitonic Coupling mentioning

confidence: 99%

mentioning

confidence: 99%

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Identification of a single peridinin sensing Chl- a excitation in reconstituted PCP by crystallography and spectroscopy

Schulte

Niedzwiedzki

Birge

et al. 2009

Proc. Natl. Acad. Sci. U.S.A.

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“…We choose a semi-empirical description for the chlorophyll electronic states as provided by the PariserParr-Pople (PPP) Hamiltonian [54,55], which has been used earlier in [26,28]. The PPP Hamiltonian…”

Section: Note Added In Revisionmentioning

confidence: 99%

Robustness and Optimality of Light Harvesting in Cyanobacterial Photosystem I

et al. 2002

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As most biological species, photosynthetic lifeforms have evolved to function optimally, despite thermal disorder and with fault tolerance. It remains a challenge to understand how this is achieved. To address this challenge the function of the protein-pigment complex photosystem I (PSI) of the cyanobacterium Synechococcus elongatus is investigated theoretically. The recently obtained high resolution structure of this complex exhibits an aggregate of 96 chlorophylls that are electronically coupled to function as a light-harvesting antenna complex. This paper constructs an effective Hamiltonian for the chlorophyll aggregate to describe excitation transfer dynamics and spectral properties of PSI. For this purpose, a new kinetic expansion method, the sojourn expansion, is introduced. Our study shows that at room temperature fluctuations of site energies have little effect on the calculated excitation lifetime and quantum yield, which compare favorably with experimental results. The efficiency of the system is found to be robust against 'pruning' of individual chlorophylls. An optimality of the arrangement of chlorophylls is identified through the quantum yield in comparison with an ensemble of randomly oriented chlorophylls, though, the quantum yield is seen to change only within a narrow interval in such an ensemble.

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“…[1][2][3][4][5][6][7][8][9][10][11] See more details in Electronic Supplementary Information (ESI). As a PP, carotenoid quenches triplet bacteriochlorophyll (BChl) special pair (SP) to prevent sensitized generation of singlet oxygen ( 1 g ).…”

mentioning

confidence: 99%

Energy dissipative photoprotective mechanism of carotenoid spheroidene from the photoreaction center of purple bacteria Rhodobacter sphaeroides

Arulmozhiraja

Nakatani

Nakayama

et al. 2015

Phys. Chem. Chem. Phys.

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Carotenoid spheroidene (SPO) works for photoprotection in the photosynthetic reaction centers (RC) and effectively dissipates its triplet excitation energy. Sensitized cis-totrans isomerization was proposed as the possible mechanism for a singlet-triplet energy crossing for the 15,15′-cis-SPO; however, it has been questioned recently. To understand the dissipative proto-protective mechanism of this important SPO and to overcome the existing controversies on this issue, we carried out a theoretical investigation using density functional theory on the possible triplet energy relaxation mechanism through the cis-to-trans isomerization. Together with the earlier experimental observations, the possible mechanism was discussed for the triplet energy relaxation of the 15,15′-cis-SPO. The result shows that complete cis-to-trans isomerization is not necessary. Twisting C15-C15′ bond leads singlettriplet energy crossing at (14,15,15′,14′) = 77 o at the energy 32.5 kJ/mol (7.7 kcal/mol) higher than that of the T 1 15,15′-cis minimum. Further exploration of the minimum-energy intersystem crossing (MEISC) point shows that triplet relaxation could happen at a less distorted structure ( =58.4 o ) with the energy height of 6.3 kcal/mol. Another important reaction coordinate to reach the MEISC point is the bond-length alternation. The model truncation effect, the solvent effect, and the spin-orbit coupling were also investigated. The singlet-triplet crossing was also investigated for the 13,14-cis stereoisomer and locked-13,14-cis-SPO. We also discussed the origin of the natural selection of cis over trans isomer in the RC.

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Excitation Transfer in the Peridinin-Chlorophyll-Protein of Amphidinium carterae

Cited by 125 publications

References 40 publications

Identification of a single peridinin sensing Chl- a excitation in reconstituted PCP by crystallography and spectroscopy

Identification of a single peridinin sensing Chl- a excitation in reconstituted PCP by crystallography and spectroscopy

Robustness and Optimality of Light Harvesting in Cyanobacterial Photosystem I

Energy dissipative photoprotective mechanism of carotenoid spheroidene from the photoreaction center of purple bacteria Rhodobacter sphaeroides

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