CONFIGURATIONS OF CAROTENOIDS IN THE REACTION CENTER and THE LIGHT‐HARVESTING COMPLEX OF Rhodospirillum rubrum. NATURAL SELECTION OF CAROTENOID CONFIGURATIONS BY PIGMENT PROTEIN COMPLEXES

Koyama, Yasushi; Takatsuka, Ichiro; Kanaji, Mariko; Tomimoto, Koichi; Kito, Mariko; Shimamura, Toshio; Yamashita, Jinpei; Saiki, Kayoko; Tsukida, Kiyoshi

doi:10.1111/j.1751-1097.1990.tb01692.x

Cited by 67 publications

(49 citation statements)

References 33 publications

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“…Cis isomers of carotenoids have been reported to be associated with different levels of biological antioxidant activity compared to their all-trans counterparts in several biological systems, but the reason for this behavior has yet to be explained (Levy et al 2000;Boehm et al 2002;Werman et al 2002). Also, different geometric isomers of carotenoids are found in various photosynthetic pigment-protein complexes (Hayashi et al 1989;Koyama et al 1990;Frank et al 1993;Frank and Cogdell 1993;Jordan et al 2001), but the role stereoisomerization plays for these molecules in photosynthesis is not clear. For example, it is known that carotenoids in reaction center pigment-protein complexes from photosynthetic bacteria adopt a 15,15¢-cis isomeric configuration whereas carotenoids in light-harvesting complexes from the same species are in an all-trans configuration (Frank and Cogdell 1993).…”

Section: Introductionmentioning

confidence: 93%

“…Reaction centers mediate electron transfer across an intracytoplasmic membrane, whereas light-harvesting complexes accomplish excitation energy transfer between chromophoric pigments. This distinction has led to the hypothesis that the natural selection of stereoisomers has physiological significance (Koyama et al 1990; Kuki et al 1995). It has been suggested that cis-to-trans isomerization of carotenoids in reaction centers is a mechanism for the efficient removal of potentially harmful triplet states of bacteriochlorophyll (Koyama et al 1990; Kuki et al 1995).…”

Section: Introductionmentioning

confidence: 99%

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Stereoisomers of Carotenoids: Spectroscopic Properties of Locked and Unlocked cis-isomers of Spheroidene

et al. 2005

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A systematic optical spectroscopic and computational investigation of a series of locked-cis-isomers of spheroidene has been carried out with the goal being to better understand the relationships between stereochemistry, photochemistry, photophysics and biological function of geometric isomers of carotenoids. The spectroscopic properties of 15,15'-locked-cis-spheroidene, 13,14-locked-cis-spheroidene, 11, 12-locked-cis-spheroidene in solution are compared with those observed for unlocked spheroidene. The locked-cis bonds are incapable of undergoing cis-to-trans isomerization and therefore provide an effective means of exploring the relationship between specific stereoisomers and molecular spectroscopy. Samples of the molecules were purified using a high performance liquid chromatography (HPLC) apparatus equipped with a diode array detector, which records the absorption spectra immediately as the molecules emerge from the column and prior to any isomerization that might occur. For several stable isomers, resonance Raman (rR) spectroscopy was carried out to assign their configurations. Quantum computations of absorption spectra were performed using ZINDO/S and also MNDO-PSDCI methods employing nearly full single and double configuration interaction within the pi-electron manifold. Also, for a few test cases, ground state minimizations were done using density functional methods (B3LYP/6-31G(d)). The MNDO-PSDCI methods coupled with the density functional ground state minimization provide an accurate assignment of the positions of the 2(1)Ag - , 1(1)Bu +, and 1(1)Ag + excited states and also address the nature of the forbidden 1(1)Bu - state, whose location is uncertain for polyenes and carotenoids. We demonstrate that the configurational description of the 1(1)Bu - state is sufficiently unique to preclude assignment of its energy based on the characterization of surrounding excited singlet states. The experimental and computational data also offer important insights into the photochemical and photophysical properties of stereoisomers of carotenoids.

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Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Stereoisomers of Carotenoids: Spectroscopic Properties of Locked and Unlocked cis-isomers of Spheroidene

et al. 2005

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“…Thus, the spectrum contains only bands caused by the chromophore. The technique has contributed considerably to our understanding of the mechanism of retinal proteins and to the investigation of chromophore-protein interaction in proteins containing heme, bilin, chlorophyll, and carotenoid chromophores (1)(2)(3)(4)(5)(6). There are only a few, but in some cases severe, drawbacks to this method, which can make its application difficult.…”

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confidence: 99%

Fourier-transform Raman spectroscopy applied to photobiological systems.

Sawatzki

Fishcer

Scheer

et al. 1990

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

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Fluorescence and initiation of photoreactions are problems frequently encountered with resonance Raman spectroscopy of photobiological systems. These problems can be circumvented with Fourier-transform Raman spectroscopy by using the 1064-nm wavelength of a continuous wave neodymium-yttrium/aluminum-garnet laser as the probing beam. This wavelength is far from the absorption band of most pigments. Yet, the spectra of the investigated systemsbacteriorhodopsin, rhodopsin, and phycocyanin-show that these systems are still dominated by the chromophore, or that preresonant Raman scattering is still prevalent. Only for rhodopsin were contributions of the protein and the membrane discernible. The spectra of phycocyanin differ considerably from those obtained by excitation into the UV-absorption band. The results show the usefulness of this method and its wide applicability. In addition, analysis of the relative preresonant scattering cross sections may provide a detailed insight into the scattering mechanism.Resonance Raman spectroscopy is a powerful technique for selectively studying chromophores in biological systems. By tuning the probing laser beam to the electronic transition of the chromophore(s) within the biological matrix (protein, lipids, etc.), the resonance-enhancement effect increases the scattering from the chromophore by several orders of magnitude. Thus, the spectrum contains only bands caused by the chromophore. The technique has contributed considerably to our understanding of the mechanism of retinal proteins and to the investigation of chromophore-protein interaction in proteins containing heme, bilin, chlorophyll, and carotenoid chromophores (1-6). There are only a few, but in some cases severe, drawbacks to this method, which can make its application difficult. Because the probing beam excites the chromophore into a higher electronic state, strong fluorescence may override the weaker spontaneous Raman scattering, making it undetectable against the fluorescence background. In active photobiological systems, the strong probing beam also initiates photoreaction(s), and special techniques must be applied to control the state of the system under investigation. This last point may become especially severe for systems in which the photoreaction is not reversible (i.e., systems that "bleach," such as vertebrate visual pigments) or in which the back-reaction is very slow (such as dark adaptation of bacteriorhodopsin or reversion of phytochrome). By pumping the sample through a capillary jet, the accumulation of the bleached state or of long-lived intermediates can be avoided, but large amounts of material are usually required.For a long time, analyzing the Raman-scattered light by a Fourier-transform (FT) spectrophotometer, or FT-Raman spectroscopy, was thought to have disadvantages as compared with conventional Raman spectroscopy (7-9). However, about 2 years ago, it was realized that by using a near-infrared laser, such as a neodymium-yttrium/aluminum-garnet (Nd:YAG) laser, as the probing beam, t...

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“…These findings raise the question: what is the function of the 9-cis isomer in the alga? Koyama et al (1990) suggest a natural selection of the carotenoid configuration in the light-harvesting complex and the reaction center. The all-trans carotene is located in the light-harvesting complex, and functions as an accessory pigment in harvesting light energy, whereas the 15-cis isomer is part of the reaction-center pigments, and its primary role is photoprotection.…”

Section: Discussionmentioning

confidence: 99%

Are active oxygen species involved in induction of ?-carotene in Dunaliella bardawil?

Shaish

Avron

Pick

et al. 1993

Planta

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Abstract. The purpose of this work was to test whether induction of massive fl-carotene synthesis in the alga Dunaliella bardawil is triggered by oxygen radicals. The following results were obtained: (i) The induction of flcarotene synthesis is preceded by a lag period of about 4 h during which the cells swell and photosynthesis is partially inhibited. (ii) Addition of promoters of oxygen radicals or of azide (an inhibitor of catalase and superoxide dismutase) during the induction period, under conditions which are suboptimal for massive fl-carotene accumulation, greatly enhances fl-carotene synthesis, photodegradation of chlorophyll and inhibition of photosynthesis. (iii) High irradiance, which induces massive fl-carotene accumulation, also induces a high catalase activity. It is suggested that photosynthetically produced oxygen radicals are involved in triggering massive flcarotene accumulation in D. bardawil.

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CONFIGURATIONS OF CAROTENOIDS IN THE REACTION CENTER and THE LIGHT‐HARVESTING COMPLEX OF Rhodospirillum rubrum. NATURAL SELECTION OF CAROTENOID CONFIGURATIONS BY PIGMENT PROTEIN COMPLEXES

Cited by 67 publications

References 33 publications

Stereoisomers of Carotenoids: Spectroscopic Properties of Locked and Unlocked cis-isomers of Spheroidene

Stereoisomers of Carotenoids: Spectroscopic Properties of Locked and Unlocked cis-isomers of Spheroidene

Fourier-transform Raman spectroscopy applied to photobiological systems.

Are active oxygen species involved in induction of ?-carotene in Dunaliella bardawil?

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