Photochemical hole-burned spectra of protonated and deuterated reaction centers of Rhodobacter sphaeroides

Lyle, Paul A.; Kolaczkowski, Stephen V.; Small, Gerald J.

doi:10.1021/j100128a030

Cited by 130 publications

(186 citation statements)

References 19 publications

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“…We suggest that the approach with a lognormal spectral density describes the phonon lineshape more accurately, 25 although to reveal the difference between our approach and that of Hayes et al, 19 i.e., to compare our parameters with the previously published data, 8,9,28 we also show fits and parameters obtained with the G-L J(ω). On the basis of previous work, 8,9,28 only two profiles corresponding to peak frequencies ω ph and ω sp are required to simultaneously fit the P870 and P960 absorption bands and ω B -dependent photochemical (transient) HB spectra. Consistent with earlier assignment, we refer to ω ph as the mean (or rather peak) phonon frequency and ω sp as the special pair marker mode.…”

Section: A Calculation Of Hb Spectramentioning

confidence: 70%

“…19, along with many later works [7][8][9][10][11][12][13][14][15][16][17][18] ). Although such a profile does provide a reasonable approximation to the true form of l R (ω) at low temperatures when the Gaussian and Lorentzian components have similar widths, the approximation breaks down quite seriously when Γ G is much different from √ RΓ L (see below).…”

Section: Derivation Of Lineshape Formulasmentioning

confidence: 97%

“…We compare el-ph coupling parameters obtained previously for Rb. sphaeroides 8,28 and Rps. viridis, 9,28 using the approach of Hayes et al, 19 with the parameters obtained in this work (using both G-L and lognormal spectral densities).…”

Section: A Calculation Of Hb Spectramentioning

confidence: 99%

“…This approach is compared below with the mean-phonon approximation used in earlier calculations, 8,9,28 where the spectral density was split into multiple effective phonon densities and the continuous weighting factor n(ω; T) was replaced by an effective factor n(ω k ; T) evaluated at a "mean" phonon frequency ω k near the peak of the kth phonon density; and where in place of numerical convolutions, multi-phonon transitions were described simply as increasingly broadened G-L profiles. We suggest that the approach with a lognormal spectral density describes the phonon lineshape more accurately, 25 although to reveal the difference between our approach and that of Hayes et al, 19 i.e., to compare our parameters with the previously published data, 8,9,28 we also show fits and parameters obtained with the G-L J(ω). On the basis of previous work, 8,9,28 only two profiles corresponding to peak frequencies ω ph and ω sp are required to simultaneously fit the P870 and P960 absorption bands and ω B -dependent photochemical (transient) HB spectra.…”

Section: A Calculation Of Hb Spectramentioning

confidence: 99%

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Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

Reppert

Kell

Pruitt

et al. 2015

The Journal of Chemical Physics

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The vibrational spectral density is an important physical parameter needed to describe both linear and non-linear spectra of multi-chromophore systems such as photosynthetic complexes. Low-temperature techniques such as hole burning (HB) and fluorescence line narrowing are commonly used to extract the spectral density for a given electronic transition from experimental data. We report here that the lineshape function formula reported by Hayes et al. [J. Phys. Chem. 98, 7337 (1994)] in the mean-phonon approximation and frequently applied to analyzing HB data contains inconsistencies in notation, leading to essentially incorrect expressions in cases of moderate and strong electron-phonon (el-ph) coupling strengths. A corrected lineshape function L(ω) is given that retains the computational and intuitive advantages of the expression of Hayes et al. [J. Phys. Chem. 98, 7337 (1994)]. Although the corrected lineshape function could be used in modeling studies of various optical spectra, we suggest that it is better to calculate the lineshape function numerically, without introducing the mean-phonon approximation. New theoretical fits of the P870 and P960 absorption bands and frequency-dependent resonant HB spectra of Rb. sphaeroides and Rps. viridis reaction centers are provided as examples to demonstrate the importance of correct lineshape expressions. Comparison with the previously determined el-ph coupling parameters [Johnson et al., J. Phys. Chem. 94, 5849 (1990); Lyle et al., ibid. 97, 6924 (1993); Reddy et al., ibid. 97, 6934 (1993)] is also provided. The new fits lead to modified el-ph coupling strengths and different frequencies of the special pair marker mode, ωsp, for Rb. sphaeroides that could be used in the future for more advanced calculations of absorption and HB spectra obtained for various bacterial reaction centers.

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Section: A Calculation Of Hb Spectramentioning

confidence: 70%

Section: Derivation Of Lineshape Formulasmentioning

confidence: 97%

Section: A Calculation Of Hb Spectramentioning

confidence: 99%

Section: A Calculation Of Hb Spectramentioning

confidence: 99%

See 2 more Smart Citations

Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

Reppert

Kell

Pruitt

et al. 2015

The Journal of Chemical Physics

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“…Evidence for heterogeneity of P conformation was also reported by Den Blanken et al (1983), who observed in A D M R experiments a pronounced dependence of the primary donor bleaching in the triplet-singlet difference spectrum on the applied microwave field. A contrasting view was advanced by Lyle et al (1993), who on the basis of hole-burning studies proposed that the role inhomogeneities involving the structure or energetics of P, play in the charge-separation kinetic, is limited.…”

Section: Charge-separation Kineticsmentioning

confidence: 99%

Spectroscopic characterization of reaction centers of the (M)Y210W mutant of the photosynthetic bacterium Rhodobacter sphaeroides

et al. 1994

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The tyrosine-(M)210 of the reaction center of Rhodobacter sphaeroides 2.4.1 has been changed to a tryptophan using site-directed mutagenesis. The reaction center of this mutant has been characterized by low-temperature absorption and fluorescence spectroscopy, time-resolved sub-picosecond spectroscopy, and magnetic resonance spectroscopy. The charge separation process showed bi-exponential kinetics at room temperature, with a main time constant of 36 ps and an additional fast time constant of 5.1 ps. Temperature dependent fluorescence measurements predict that the lifetime of P* becomes 4-5 times slower at cryogenic temperatures. From EPR and absorbance-detected magnetic resonance (ADMR, LD-ADMR) we conclude that the dimeric structure of P is not significantly changed upon mutation. In contrast, the interaction of the accessory bacteriochlorophyll B A with its environment appears to be altered, possibly because of a change in its position.

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Excitation energy trapping by the reaction center ofRhodobacter Sphaeroides

Damjanovi

Ritz

Schulten

2000

Int. J. Quant. Chem.

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The excitation energy transfer between light-harvesting complex I (LH-I)and the photosynthetic reaction center (RC) of the purple bacterium Rhodobacter (Rb.) sphaeroides is investigated on the basis of the atomic level structures of the two proteins, assuming a ring-shaped model for LH-I. Rates of excitation energy transfer are calculated, based on Förster theory. The LH-I and RC electronic excitations are described through effective Hamiltonians established previously, with parameters derived from quantum chemistry calculations by Cory and co-workers. We also present an effective Hamiltonian description with parameters based on spectroscopic properties. We study two extreme models of LH-I excitations: electronic excitations delocalized over the entire LH-I ring and excitations localized on single bacteriochlorophylls. The role of accessory bacteriochlorophylls in bridging the excitation energy transfer is investigated. The rates of back-transfer, i.e., RC → LH-I excitation energy transfer, are determined, too.

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Photochemical hole-burned spectra of protonated and deuterated reaction centers of Rhodobacter sphaeroides

Cited by 130 publications

References 19 publications

Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

Comments on the optical lineshape function: Application to transient hole-burned spectra of bacterial reaction centers

Spectroscopic characterization of reaction centers of the (M)Y210W mutant of the photosynthetic bacterium Rhodobacter sphaeroides

Excitation energy trapping by the reaction center ofRhodobacter Sphaeroides

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