Recent Contributions in Phycobiliproteins and Phycobilisomes

Gantt, Elisabeth

doi:10.1111/j.1751-1097.1977.tb07553.x

Cited by 20 publications

(4 citation statements)

References 53 publications

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“…These interactions are, in part, responsible for the range of colors emitted in firefly bioluminescence (Seliger and McElroy, 1964;Biggley et al, 1967). for the range of photoreceptor sensitivities in visual systems (Dartnall and Lythgoe, 1965), and for the spectral identity and energy transfer function of light harvesting pigment proteins in photosynthesis (Gantt, 1975;Glazer, 1976;Gantt, 1977). Thus, aside from their interest as components of bioluminescence energy transfer systems, the green-fluorescent proteins may also serve as useful models for the more general study of protein-chromophore interaction and protein-induced spectral changes in protein-bound chromophores.…”

Section: Resultsmentioning

confidence: 99%

Spectrophotometric Identity of the Energy Transfer Chromophores in Renilla and Aequorea Green‐fluorescent Proteins

Ward

Cody

Hart

et al. 1980

Photochem & Photobiology

210

135

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Abstract— Spectral properties of guanidine‐denaturated and pronase‐digested green‐fluorescent proteins (GFP) from two species of bioluminescent coelenterates have been investigated. Spectrophotometric titrations of Renilla and Aequorea GFP, following denaturation in 6M guanidine HCl at elevated temperature, revealed identical absorption peaks in acid (383–384 nm) and in alkali (447–448 nm) and a single isosbestic point in the visible region at 405 nm. Both proteins exhibited a spectrophotometric pK. of 8.1 in guanidine ‐HCl. Pronase digestion of the heat‐denaturated GFP's generated a methanol‐soluble blue‐fluorescent peptide with identical fluorescence emission spectra (λmax= 430 nm, uncorrected; φf1= 0.003) for both coelenterate species. These data suggest that the large absorption differences between native Renilla and Aequorea GFP molecules result from unique protein environments imported to a common chromophore.

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Section: Resultsmentioning

confidence: 99%

Spectrophotometric Identity of the Energy Transfer Chromophores in Renilla and Aequorea Green‐fluorescent Proteins

Ward

Cody

Hart

et al. 1980

Photochem & Photobiology

210

135

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“…The cyanobacteria (PG 13), here represented by Synechococcus sp., are unique both in terms of biooptical properties and pigmentation. They are characterized by of 679 nm and F II as low as 0.12, and it appears that most of the chl a is bonded to PSI (Gantt 1977, Rhiel et al. 1987, Johnsen and Sakshaug 1996).…”

Section: Discussionmentioning

confidence: 99%

Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse‐amplitude‐modulated and fast‐repetition‐rate fluorometry¹

Johnsen

Sakshaug

2007

Journal of Phycology

173

190

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We studied the variability of in vivo absorption coefficients and PSII-scaled fluorescence excitation (fl-ex) spectra of high light (HL) and low light (LL) acclimated cultures of 33 phytoplankton species that belonged to 13 different pigment groups (PGs) and 10 different phytoplankton classes. By scaling fl-ex spectra to the corresponding absorption spectra by matching them in the 540-650 nm range, we obtained estimates for the fraction of total chl a that resided in PSII, the absorption of light by PSII, PSI, and photoprotective carotenoids. The in vivo red peak absorption maxima ranged from 673 to 679 nm, reflecting bonding of chl a to different pigment proteins. A simple approach is presented for quantifying intracellular self-shading and evaluating the impact of photoacclimation on biooptical characteristics of the different PGs examined. In view of these results, parameters used in the calculation of oxygenic photosynthesis based on pulse-amplitude-modulated (PAM) and fast-repetition-rate (FRR) fluorometers are discussed, showing that the ratio between light available to PSII and total absorption, essential for the calculation of the oxygen release rate (using the PSII-scaled fluorescence spectrum as a proxy) was dependent on species and photoacclimation state. Three subgroups of chromophytes exhibited 70%-80%, 60%-80%, and 50%-60% chl a in PSII-LHCII; the two subgroups of chlorophytes, 70% or 80%; and cyanobacteria, only 12%. In contrast, the mean fraction for chromo-and chlorophytes of quanta absorbed by PSII was 73% in LL-and 55% in HL-acclimated cells; thus, the corresponding ratios 0.55 and 0.73 might be used as correction factors adjusting for quanta absorbed by PSII for PAM and FRR measurements.Key index words: 13 pigment groups of phytoplankton; absorbed quanta to PSII; chl a AE C )1 ratio; package effect; photoacclimation; PSII-scaled fl-ex spectra; variable fluorescence Abbreviations: ACP, chl a-chl c-peridinin protein complex; chl a AE C )1 ratio, chl a to carbon ratio (w:w); DCMU, dichlorophenyl methyl urea; E, irradiance (lmol photons AE m )2 AE s )1 ); fl-ex, fluorescence excitation; FRR, fast repetition rate;

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“…The phycobilin pigments appear to be contained in a structure known as a phycobilisome. The structure of the phycobilisome was proposed by Gantt (1977), Gantt et al (1976), and Bryant et al (1979). An allophycocyanin core was surrounded by a hemispherical layer of phycocyanin which in turn was surrounded by a hemispherical layer of phycoerythrin.…”

Section: Introductionmentioning

confidence: 99%

Picosecond energy transfer in Porphyridium cruentum and Anacystis nidulans

Brody¹,

Treadwell²,

Barber³

1981

Biophysical Journal

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Picosecond energy transfer is measured in Anacystis nidulans and Porphyridium cruentum. Fluorescence is sensitized by a 6-ps laser flash, at 530 nm. The time dependence of fluorescence is measured with reference to the laser pulse. Fluorescence is recorded from phycoerythrin (576 nm), R-phycocyanin (640 nm), allophycocyanin (666 nm), Photosystem II chlorophyll (690 nm) and long wave length chlorophyll (715 nm). Energy transfer measurements are made at 37 degrees C, 23 degrees C, and 0 degrees C, and 77 degrees K. It is shown that the rate of energy transfer can be varied with temperature. In both A. nidulans and P. cruentum there is a sequential transfer of excitation energy from phycoerythrin to phycocyanin to allophycocyan to Photosystem II chlorophyll fluorescence. The long wavelength chlorophyll fluorescence at 715 nm, however, does not always follow a sequential transfer of excitation energy. Depending on the temperature, fluorescence at 715 nm can precede fluorescence from phycocyanin.

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Recent Contributions in Phycobiliproteins and Phycobilisomes

Cited by 20 publications

References 53 publications

Spectrophotometric Identity of the Energy Transfer Chromophores in Renilla and Aequorea Green‐fluorescent Proteins

Spectrophotometric Identity of the Energy Transfer Chromophores in Renilla and Aequorea Green‐fluorescent Proteins

Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse‐amplitude‐modulated and fast‐repetition‐rate fluorometry¹

Picosecond energy transfer in Porphyridium cruentum and Anacystis nidulans

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Recent Contributions in Phycobiliproteins and Phycobilisomes

Cited by 20 publications

References 53 publications

Spectrophotometric Identity of the Energy Transfer Chromophores in Renilla and Aequorea Green‐fluorescent Proteins

Spectrophotometric Identity of the Energy Transfer Chromophores in Renilla and Aequorea Green‐fluorescent Proteins

Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse‐amplitude‐modulated and fast‐repetition‐rate fluorometry1

Picosecond energy transfer in Porphyridium cruentum and Anacystis nidulans

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Biooptical characteristics of PSII and PSI in 33 species (13 pigment groups) of marine phytoplankton, and the relevance for pulse‐amplitude‐modulated and fast‐repetition‐rate fluorometry¹