Interpretation of the resonance Raman spectrum of bathorhodopsin based on visual pigment analogs

Eyring, Gregory; Curry, Bostick; Mathies, Richard A.; Fransen, Ruud; Palings, I.; Lugtenburg, J.

doi:10.1021/bi00552a020

Cited by 157 publications

(161 citation statements)

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“…This assignment is supported by the similar 955-to 965-cm 21 frequency calculated for these modes by normal-coordinate analysis of all-trans b-carotene (Saito and Tasumi, 1983). HOOP modes can serve as direct reporters of out-of-plane distortions, since the intensity of these modes are typically quite low for a planar polyene but increase if local symmetry in the vicinity of the bond is broken (Eyring et al, 1980). Thus, we expect the intensity of this mode in OCP O to originate from torsional distortions to the polyene chain enhancing one or more of the A u -type CH5CH HOOP modes.…”

Section: Spectroscopic Characterization Of Ocp O Ocp R and Rcpmentioning

confidence: 62%

Structural and Functional Modularity of the Orange Carotenoid Protein: Distinct Roles for the N- and C-Terminal Domains in Cyanobacterial Photoprotection

et al. 2014

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The orange carotenoid protein (OCP) serves as a sensor of light intensity and an effector of phycobilisome (PB)-associated photoprotection in cyanobacteria. Structurally, the OCP is composed of two distinct domains spanned by a single carotenoid chromophore. Functionally, in response to high light, the OCP converts from a dark-stable orange form, OCP O , to an active red form, OCP R . The C-terminal domain of the OCP has been implicated in the dynamic response to light intensity and plays a role in switching off the OCP's photoprotective response through its interaction with the fluorescence recovery protein. The function of the N-terminal domain, which is uniquely found in cyanobacteria, is unclear. To investigate its function, we isolated the N-terminal domain in vitro using limited proteolysis of native OCP. The N-terminal domain retains the carotenoid chromophore; this red carotenoid protein (RCP) has constitutive PB fluorescence quenching activity comparable in magnitude to that of active, full-length OCP R . A comparison of the spectroscopic properties of the RCP with OCP R indicates that critical proteinchromophore interactions within the C-terminal domain are weakened in the OCP R form. These results suggest that the C-terminal domain dynamically regulates the photoprotective activity of an otherwise constitutively active carotenoid binding N-terminal domain.

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Section: Spectroscopic Characterization Of Ocp O Ocp R and Rcpmentioning

confidence: 62%

Structural and Functional Modularity of the Orange Carotenoid Protein: Distinct Roles for the N- and C-Terminal Domains in Cyanobacterial Photoprotection

et al. 2014

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“…The difference in spectra between bathorhodopsins from 11-cisand 9-cis rhodopsin (Fig. 4 a and b), as well as resonance Raman studies of 11-cis-bathorhodopsin (27)(28)(29)(30), suggest that the chromophore has a distorted trans structure. Our observations emphasize that there is not a common bathorhodopsin state produced from 11-cis-or 9-cis-rhodopsin.…”

Section: 1mentioning

confidence: 89%

Bathorhodopsin intermediates from 11-cis-rhodopsin and 9-cis-rhodopsin.

Spalink¹,

Reynolds²,

Rentzepis³

et al. 1983

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

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Bathorhodopsin-rhodopsin difference spectra of native 11-cis-rhodopsin and regenerated 9-cis-rhodopsin were measured at room temperature with a double-beam laser spectrophotometer after excitation at 532 nm. A detailed analysis of data obtained at 85 psec after excitation suggests that the bathorhodopsins generated from 1 1-cis-and 9-cis-rhodopsin differ in their extinction coefficients and that their absorption maxima are shifted in wavelength by about 10 nm from one another. The ratio of quantum yields for photochemical production of the 11-cis-bathorhodopsin and the 9-cis-bathorhodopsin approximates 1. Implications that the early photochemical processes in vision are more complex than previously considered are explored.An improved double-beam laser spectrophotometer was developed to perform a comparative study of the bathorhodopsin photoproducts of native 11-cis-rhodopsin and regenerated 9-cis-rhodopsin. The instrument measures difference spectra of the initial photoproduct (bathorhodopsin) minus the rhodopsin converted for each of these visual pigments under identical experimental conditions. Each spectrum, covering the range of 400-650 nm, was recorded with a single monitoring pulse after excitation at 532 nm. Particular attention was given to optimizing the signal-to-noise ratio of measured absorbance changes in order to achieve data collection with excitation pulse energies that were low enough to avoid multiphoton events. Our goal was to establish, as best possible, characteristic absorption spectra of the transient bathophotoproducts arising from 11-cis-and 9-cis-rhodopsin at room temperature and to compare these with the published spectra obtained by photostationary studies carried out with aqueous glycerol/rhodopsin glasses at low temperature.METHODS AND MATERIALS Visual Pigment Samples. Buffer is defined throughout this work as 0.01 M Hepes, pH 7/0.1 mM EDTA/1.0 mM dithiothreitol. Rhodopsin was prepared from frozen bovine retinae (G. Hormel), solubilized in Ammonyx-LO detergent, and purified by hydroxyapatite chromatography (1, 2). The relative purity of the samples used is indicated by the ratio A278/ A498 = 1.9 + 0.1. For preparation of regenerated 9-cis-rhodopsin, the 9-cis-retinaldehyde isomerwas made byphotolysis of all-trans-retinal (Fluka, Buchs, Switzerland) dissolved in trifluoroethane, with appropriately filtered light (Schott 06455 and 06745). 9-cis-Retinal was isolated by preparative HPLC and was found to be >99% pure by analytical HPLC. The retinal was stored at -700C under N2 until incorporated into opsin. 9-cis-Rhodopsin was prepared from opsin, made by washing bleached disk membranes with buffered NH2OH, and purified 9-cis-retinal. The regenerated pigment was solubilized and purified by hydroxyapatite chromatography (1, 2). The relative purity is indicated by the ratio A278/A485 = 1.8 ± 0.1. The purified 9-cis-rhodopsin was shown to contain the 9-cis-retinal isomer by HPLC. The molar extinction coefficients used throughout this work were eri (498 nm) = 4.06 X 104 M'1cm-1 for ...

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“…Summary of the HOOP bands of the primary photoproducts in resonance Raman spectra of different visual pigments. The peak positions of HOOP modes in the Batho state are indicated for the WT bovine rhodopsin, S186I, S186A, E181D, E181Q, E113A, E113Q (53), 5-demethyl rhodopsin, 9-demethyl rhodopsin (26), octopus rhodopsin (56), toad (Bufo marinus) red rod, angelfish (Pterophyllum scalare) rods, gecko (Gekko gecko) rod, bullfrog (Rana catesbeiana) rod (54), and chicken (Gallus domesticus) iodopsin (55). (A) Absolute sense and magnitude of the rotations at the C 11 =C 12 and C 12 -C 13 bonds during the cis-trans isomerization in rhodopsin.…”

Section: Discussionmentioning

confidence: 99%

Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion in the Primary Visual Photoproduct

et al. 2004

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The vibrational structure of the chromophore in the primary photoproduct of vision, bathorhodopsin, is examined to determine the cause of the anomalously decoupled and intense C 11 =C 12 hydrogenout-of-plane (HOOP) wagging modes and their relation to energy storage in the primary photoproduct. Low-temperature (77 K) resonance Raman spectra of Glu181 and Ser186 mutants of bovine rhodopsin reveal only mild mutagenic perturbations of the photoproduct spectrum suggesting that dipolar, electrostatic, or steric interactions with these residues do ded by NIHnot cause the HOOP mode frequencies and intensities. Density functional theory calculations are performed to investigate the effect of geometric distortion on the HOOP coupling. The decoupled HOOP modes can be simulated by imposing ∼40° twists in the same direction about the C 11 =C 12 and C 12 -C 13 bonds. Sequence comparison and examination of the binding site suggests that these distortions are caused by three constraints consisting of an electrostatic anchor between the protonated Schiff base and the Glu113 counterion, as well as steric interactions of the 9-and 13-methyl groups with surrounding residues. This distortion stores light energy that is used to drive the subsequent protein conformational changes that activate rhodopsin.Photoactive proteins play a vital role in a variety of light-energy and light-signaling processes that are characterized by pico-to femtosecond light-driven structural changes of a proteinbound chromophore followed by activated conformational changes of the protein. In systems such as rhodopsin (Rho) 1 (1), bacteriorhodopsin (2,3), halorhodopsin (4), photoactive yellow protein (5), and phytochrome (6,7), primary high-energy intermediates are produced with structurally perturbed chromophores. What is the nature of the protein-chromophore interactions that store the energy needed to drive subsequent protein conformational changes? To address this question, we have studied the photoactivation of rhodopsin, a dim-light photoreceptor, using a multidisciplinary approach that integrates Raman spectroscopy, mutagenesis, density functional theory (DFT) calculations, and bioinformatic analysis. † Funding was provided by NIH Grant EY02051 (to R.A.M. Rho is a paradigmatic G protein-coupled receptor, whose 7-transmembrane helical structure forms a binding pocket for 11-cis-retinal, which is covalently linked to Lys296 on helix 7. Within 200 fs after photoexcitation (8,9), the 11-cis-retinal protonated Schiff base (PSB) isomerizes to all-trans-retinal (ATR) with a quantum yield of 0.65 to form the primary photoproduct, Bathorhodopsin (10,11), which stores ∼30 kcal/mol or ∼60% of the incident photon energy (Figure 1) (12)(13)(14). Subsequently, the highly distorted chromophore relaxes, and the transduced energy is used to drive conformational changes in the opsin protein (15)(16)(17)(18). Recently, we found that this structural evolution includes a retinal counterion switch from Glu113 in the dark state to Glu181 in the metarhodopsin I (Met...

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Interpretation of the resonance Raman spectrum of bathorhodopsin based on visual pigment analogs

Cited by 157 publications

References 50 publications

Structural and Functional Modularity of the Orange Carotenoid Protein: Distinct Roles for the N- and C-Terminal Domains in Cyanobacterial Photoprotection

Structural and Functional Modularity of the Orange Carotenoid Protein: Distinct Roles for the N- and C-Terminal Domains in Cyanobacterial Photoprotection

Bathorhodopsin intermediates from 11-cis-rhodopsin and 9-cis-rhodopsin.

Resonance Raman Analysis of the Mechanism of Energy Storage and Chromophore Distortion in the Primary Visual Photoproduct

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