Primary Charge-Separation Rate at 5 K in Isolated Photosystem II Reaction Centers Containing Five and Six Chlorophyll <i>a</i> Molecules

Jankowiak, Ryszard; Rätsep, Margus; Hayes, John M.; Zazubovich, Valter; Picorel, Rafael; Seibert, and M.; Small, Gerald J.

doi:10.1021/jp021787d

Cited by 15 publications

(32 citation statements)

References 51 publications

(113 reference statements)

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“…34,35 The pseudo-PSBH is due to states whose ZPL lies to lower energy of the laser frequency and which absorb via their phonon sideband. 34,35 The spectra in frames A, B, E, and F are similar to those reported earlier 26,30 with λ B at or in the near vicinity of 680 nm. The TBHB spectra are due to 3 P680* formed by charge recombination of P680 + Pheo 1 -.…”

Section: Methodssupporting

confidence: 82%

“…19,[21][22][23][24][25][26] The triplet bottleneck hole burned (TBHB) spectra in ref 26 led to a value of 4.6 ( 0.4 ps -1 for both RC-5 and RC-6 at 5.0 K, establishing that removal of one of the two peripheral Chls does not affect the primary charge separation rate. The 1.3 K two-pulse photon echo decay curves of Prokhorenko and Holzwarth 3 are interesting in that they are dispersive (nonsingle exponential).…”

Section: Introductionmentioning

confidence: 99%

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How Fast Is Excitation Energy Transfer in the Photosystem II Reaction Center in the Low Temperature Limit? Hole Burning vs Photon Echo

et al. 2003

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The Q y (S 1 ) excitonic structure, excitation energy transfer (EET), and primary charge-transfer separation processes of the isolated photosystem II reaction center (PS II RC) have proven to be formidable problems due, in part, to the severe spectral congestion of the S o fQ y absorption spectrum. Recently, Prokhorenko and Holzwarth (J. Phys. Chem. B 2000, 104, 11563) reported interesting femtosecond 2-pulse photon echo data on the RC at 1.3 K for excitation wavelengths between 676 and 686 nm. At times longer than ∼1 ps and λ J 678 nm, the echo decay curves are highly dispersive, which was attributed to a distribution of primary charge separation rates ranging from 2 ps to several hundred ps. A prompt subpicosecond component of the echo decay curves was also observed and suggested to be due to EET occurring in ∼100-200 fs. We present here persistent nonphotochemical hole burned spectra and transient triplet bottleneck hole spectra obtained with burn wavelengths between 680 and 686 nm, which show that the EET time in that wavelength region is no shorter than ∼5-10 ps. It is argued that the prompt component of the echo decay curves is due to relaxation of low-frequency phonons excited by the pump pulse. The argument is based on hole burning spectroscopy being the frequency domain equivalent of 2-photon echo spectroscopy, as well as on published photon echo data for chromophores in amorphous hosts.

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Section: Methodssupporting

confidence: 82%

Section: Introductionmentioning

confidence: 99%

How Fast Is Excitation Energy Transfer in the Photosystem II Reaction Center in the Low Temperature Limit? Hole Burning vs Photon Echo

et al. 2003

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“…The recent X-ray structure of the Photosystem II (PSII) reaction center (RC) at 1.9 Å resolution 1 has confirmed that some of the general features of the PSII RC are homologous to those of the bacterial RC (BRC). 2 The S 1 (Q y )-electronic structure, excitation energy transfer (EET), and primary charge separation (CS) processes in the D 1 -D 2 -Cytb 559 RC complex of PSII (PSII RC) of plants, [3][4][5][6][7][8][9] cyanobacteria, [10][11][12][13][14] and algae [15][16][17][18] have been the subjects of many timedomain [18][19][20][21][22] and frequency-domain studies [23][24][25][26][27][28] . Although in recent years consistent progress has been made in our understanding of the electronic structure and CS dynamics of the isolated PSII RC, 10,[29][30][31] an adequate global understanding has yet to be achieved.…”

Section: Introductionmentioning

confidence: 99%

Site Energies of Active and Inactive Pheophytins in the Reaction Center of Photosystem II from Chlamydomonas reinhardtii

Acharya¹,

Neupane²,

Zazubovich

et al. 2012

J. Phys. Chem. B

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It is widely accepted that the primary electron acceptor in various Photosystem II (PSII) reaction center (RC) preparations is pheophytin a (Pheo a) within the D1 protein (Pheo(D1)), while Pheo(D2) (within the D2 protein) is photochemically inactive. The Pheo site energies, however, have remained elusive, due to inherent spectral congestion. While most researchers over the past two decades placed the Q(y)-states of Pheo(D1) and Pheo(D2) bands near 678-684 and 668-672 nm, respectively, recent modeling [Raszewski et al. Biophys. J. 2005, 88, 986 - 998; Cox et al. J. Phys. Chem. B 2009, 113, 12364 - 12374] of the electronic structure of the PSII RC reversed the assignment of the active and inactive Pheos, suggesting that the mean site energy of Pheo(D1) is near 672 nm, whereas Pheo(D2) (~677.5 nm) and Chl(D1) (~680 nm) have the lowest energies (i.e., the Pheo(D2)-dominated exciton is the lowest excited state). In contrast, chemical pigment exchange experiments on isolated RCs suggested that both pheophytins have their Q(y) absorption maxima at 676-680 nm [Germano et al. Biochemistry 2001, 40, 11472 - 11482; Germano et al. Biophys. J. 2004, 86, 1664 - 1672]. To provide more insight into the site energies of both Pheo(D1) and Pheo(D2) (including the corresponding Q(x) transitions, which are often claimed to be degenerate at 543 nm) and to attest that the above two assignments are most likely incorrect, we studied a large number of isolated RC preparations from spinach and wild-type Chlamydomonas reinhardtii (at different levels of intactness) as well as the Chlamydomonas reinhardtii mutant (D2-L209H), in which the active branch Pheo(D1) is genetically replaced with chlorophyll a (Chl a). We show that the Q(x)-/Q(y)-region site energies of Pheo(D1) and Pheo(D2) are ~545/680 nm and ~541.5/670 nm, respectively, in good agreement with our previous assignment [Jankowiak et al. J. Phys. Chem. B 2002, 106, 8803 - 8814]. The latter values should be used to model excitonic structure and excitation energy transfer dynamics of the PSII RCs.

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“…He also explored PS II, the protein-pigment complex involved in oxygen production in algae and higher plants. Both were done with the cooperation of a number of collaborators (Jankowiak et al 1989(Jankowiak et al , 2003. One of us (MS) remembers numerous discussions of PS II over dinners at the Aunt Maude's restaurant during visits to Ames in this period, many times including Therese Cotton, who passed away in 1998.…”

mentioning

confidence: 99%

Remembering Gerald J. Small (1941–2004), who tackled everything in life with an intense and enviable passion

Jankowiak

Seibert

2005

Photosynth Res

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Primary Charge-Separation Rate at 5 K in Isolated Photosystem II Reaction Centers Containing Five and Six Chlorophyll a Molecules

Cited by 15 publications

References 51 publications

How Fast Is Excitation Energy Transfer in the Photosystem II Reaction Center in the Low Temperature Limit? Hole Burning vs Photon Echo

How Fast Is Excitation Energy Transfer in the Photosystem II Reaction Center in the Low Temperature Limit? Hole Burning vs Photon Echo

Site Energies of Active and Inactive Pheophytins in the Reaction Center of Photosystem II from Chlamydomonas reinhardtii

Remembering Gerald J. Small (1941–2004), who tackled everything in life with an intense and enviable passion

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