Fourier transform infrared spectrum of the radical cation of β‐carotene photoinduced in photosystem II

Noguchi, Takumi; Mitsuka, Tomoya; Inoue, Yorinao

doi:10.1016/0014-5793(94)01263-6

Cited by 69 publications

(68 citation statements)

References 23 publications

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“…This may in part be due to the difficulty in distinguishing the EPR spectra of P-carotene and Chl cation radicals. However, the infrared spectrum of photoinduced p-carotene radicals in PS I1 membrane preparations was recently reported by Noguchi et al (341).…”

Section: Carotenoid Radicalsmentioning

confidence: 88%

Radicals and Radical Pairs in Photosynthesis

Angerhofer

Bittl

1996

Photochem & Photobiology

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Section: Carotenoid Radicalsmentioning

confidence: 88%

Radicals and Radical Pairs in Photosynthesis

Angerhofer

Bittl

1996

Photochem & Photobiology

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“…The excitation and emission slit widths were 5 and 2 nm, respectively. At 200 K, Chl Z ϩ is the predominant cation that photoaccumulates (26,44). Steady-state Chl fluorescence emission spectra of the PSII membranes before and after the chlorophyll fluorescencequenching treatment at 200 K (as described above) were measured at 77 K by using an excitation wavelength of 468 nm with excitation and emission slit widths of 2 nm.…”

Section: Materials and Methods Generation Of Mutantsmentioning

confidence: 99%

Functional asymmetry of photosystem II D1 and D2 peripheral chlorophyll mutants of Chlamydomonas reinhardtii

Wang

Gosztola

Ruffle

et al. 2002

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

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The peripheral accessory chlorophylls (Chls) of the photosystem II (PSII) reaction center (RC) are coordinated by a pair of symmetryrelated histidine residues (D1-H118 and D2-H117). These Chls participate in energy transfer from the proximal antennae complexes (CP43 and CP47) to the RC core chromophores. In addition, one or both of the peripheral Chls are redox-active and participate in a low-quantum-yield electron transfer cycle around PSII. We demonstrate that conservative mutations of the D2-H117 residue result in decreased Chl fluorescence quenching efficiency attributed to reduced accumulation of the peripheral accessory Chl cation, Chl Z ؉ . In contrast, identical symmetry-related mutations at residue D1-H118 had no effect on A mong the photosynthetic organisms, there are two different, quinone-type photosynthetic reaction centers (RCs): the oxygenic type present in chloroplasts and cyanobacteria (photosystem II, PSII) and the nonoxygenic type (bacterial reaction center, BRC) as typified by that in purple-sulfur photosynthetic bacteria (for reviews, see refs. 1 and 2). In 1984, the crystal structure of the Rhodopseudomonas viridis BRC was determined at 3-Å resolution by Deisenhofer et al. (3). It soon was recognized that the L and M polypeptides of the BRC had substantial amino acid sequence similarity with the PSII D1 and D2 proteins, respectively. Early models of the D1 and D2 proteinfolding topologies indicated that the PSII D1 and D2 polypeptides were structurally analogous to the L and M subunits (3-8). These models of the PSII RC polypeptides and their associated cofactors were verified by electron and x-ray diffraction of twoand three-dimensional PSII crystals (9-12). Recently, a 3.8-Å resolution structure of the oxygen-evolving PSII complex from Synechecoccus elongatus was determined (13).The PSII RC has six chlorophylls (Chls), two pheophytins (Pheos), two quinones, and one cytochrome b 559 (Cyt b 559 ) heme (8, 13). Significantly, the PSII RC has two additional Chls, relative to the BRC. Site-directed mutagenesis and spectroscopic studies demonstrated that the additional pair of Chls present in PSII is coordinated by a pair of conserved and C 2 symmetryrelated histidine residues (D1-H118 and D2-H117, Chlamydomonas reinhardtii nomenclature) (14-20). Unlike the four Chls and two Pheos involved in primary charge separation, the additional pair of Chls present in the PSII RC is located on the periphery of D1 and D2 polypeptides.Biophysical evidence for the involvement of the peripheral Chls in energy transfer first was obtained from analysis of P680 oxidation kinetics by Schelvis et al. (14). They observed a Ϸ30-ps P680 oxidation lifetime component, which they attributed to energy transfer from a Chl monomer to P680. Based on a Förster mechanism (21) for energy transfer, they calculated that the distance between the peripheral Chl and P680 was 30 Å, a distance confirmed by the recent PSII crystal structure. A similar distance relationship also was predicted on the basis of Chl fluorescence decay kine...

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“…This electron transfer cycle includes plastoquinone bound at the B binding site (Q B ), Cyt b 559 , Chl Z (the redox active Chl monomer coordinated by either the D1-H118 or D2-H117 residue), possibly (Car) carotenoid, and the primary donor, P680 ϩ (Koulougliotis et al, 1994;Noguchi et al, 1994;Hanley et al, 1999;Vrettos et al, 1999). Under high-light intensities, both P680 ϩ and doubly reduced Q A may accumulate leading to damage and turnover of the D1 protein (photo-inhibition; Chen et al, 1992;Andersson and Barber, 1996;Napiwotzki et al, 1997;Gadjieva et al, 2000).…”

mentioning

confidence: 99%

“…For Chl Z to be oxidized by P680 ϩ , however, it must be sufficiently close to either P680 ϩ for direct electron transfer or to some potential intermediate electron carrier, such as a Car or Pheo (Noguchi et al, 1994). As hypothesized by Schelvis et al (1994) the peripheral Chls coordinated by the D1-H118 and D2-H117 residues are sufficiently far removed (approximately 30 Å) from the Chl special pair (P680) to reduce the likelihood of their direct oxidation by P680 ϩ .…”

mentioning

confidence: 99%

Photosystem II Peripheral Accessory Chlorophyll Mutants inChlamydomonas reinhardtii. Biochemical Characterization and Sensitivity to Photo-Inhibition,

et al. 2001

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In addition to the four chlorophylls (Chls) involved in primary charge separation, the photosystem II (PSII) reaction center polypeptides, D1 and D2, coordinate a pair of symmetry-related, peripheral accessory Chls. These Chls are axially coordinated by the D1-H118 and D2-H117 residues and are in close association with the proximal Chl antennae proteins, CP43 and CP47. To gain insight into the function(s) of each of the peripheral Chls, we generated site-specific mutations of the amino acid residues that coordinate these Chls and characterized their energy and electron transfer properties. Our results demonstrate that D1-H118 and D2-H117 mutants differ with respect to: (a) their relative numbers of functional PSII complexes, (b) their relative ability to stabilize charge-separated states, (c) light-harvesting efficiency, and (d) their sensitivity to photo-inhibition. The D2-H117N and D2-H117Q mutants had reduced levels of functional PSII complexes and oxygen evolution capacity as well as reduced light-harvesting efficiencies relative to wild-type cells. In contrast, the D1-H118Q mutant was capable of near wild-type rates of oxygen evolution at saturating light intensities. The D1-H118Q mutant also was substantially more resistant to photo-inhibition than wild type. This reduced sensitivity to photo-inhibition is presumably associated with a reduced light-harvesting efficiency in this mutant. Finally, it is noted that the PSII peripheral accessory Chls have similarities to a to a pair of Chls also present in the PSI reaction center complex.Photosystem II (PSII) is a membrane-bound pigment-protein complex that catalyzes the light-driven oxidation of water and reduction of plastoquinone. The simplest functional PSII complex capable of charge separation is the reaction center complex. The PSII reaction center complex contains five polypeptides (Nanba and Satoh, 1987;Gounaris et al., 1990). The largest polypeptides (32 kD) are the D1 and D2 polypeptides, each of which has five transmembranespanning alpha helices. Sandwiched between the D1 and D2 polypeptides are the four chlorophylls (Chls) and two pheophytins (Pheos) involved in primary charge separation (for review, see Ruffle and Sayre, 1998). Three additional small (10 kD) polypeptides are present in the PSII reaction center complex. Two of these proteins, psbE and psbF, coordinate the redox active heme, cytochrome (Cyt) b 559 . This heme is not involved in primary charge separation but participates in a low quantum yield electron transfer cycle around PSII that protects the complex from photodamage (Buser et al., 1992; Stewart et al., 1998). The fifth protein component is the psbI protein, a small structural polypeptide that stabilizes the complex (Nanba and Satoh, 1987).Amino acid sequence similarities between the D1 and D2 proteins and the analogous L and M subunits of the bacterial (Rhodopseudomonas viridis) photosynthetic reaction center indicated that the PSII reaction center was structurally analogous to the bacterial photosynthetic reaction center (Deisen...

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Fourier transform infrared spectrum of the radical cation of β‐carotene photoinduced in photosystem II

Cited by 69 publications

References 23 publications

Radicals and Radical Pairs in Photosynthesis

Radicals and Radical Pairs in Photosynthesis

Functional asymmetry of photosystem II D1 and D2 peripheral chlorophyll mutants of Chlamydomonas reinhardtii

Photosystem II Peripheral Accessory Chlorophyll Mutants inChlamydomonas reinhardtii. Biochemical Characterization and Sensitivity to Photo-Inhibition,

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