Limited sensitivity of pigment photo-oxidation in isolated thylakoids to singlet excited state quenching in photosystem II antenna

Santabarbara, Stefano

doi:10.1016/j.abb.2006.08.017

Cited by 24 publications

(16 citation statements)

References 73 publications

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“…1) showed that disappearance of the shoulder around 490 nm was mainly due to bleaching of carotenoid molecules. Our results are in line with recent observations of fast carotenoid pool bleaching in PSI particles (32) and in thylakoids (33). RR investigation of carotenoid bleaching (Figs.…”

Section: Discussionsupporting

confidence: 93%

Selective Photobleaching of Chlorophylls and Carotenoids in Photosystem I Particles under High‐Light Treatment

Andreeva¹,

Abarova²,

Stoitchkova³

et al. 2007

Photochem & Photobiology

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Photosystem I particles (PSI-200) isolated from spinach leaves were studied by means of absorbance, 77K fluorescence and resonance Raman (RR) spectroscopy. The aim was to obtain better insight into the changes of the pigment spectral properties in those particles during prolonged exposure to high-light intensities and to reveal the involvement of these pigments in the photoprotection of the PSI. During prolonged exposure to high-light intensities of spinach PSI particles, a loss of a significant amount of photosynthetic pigments was observed. It was shown that various pigments exhibited different susceptibility to photodamage. In addition to bleaching of chlorophyll a (Chl a), bleaching of carotenoids was also clearly observed. RR technique allowed us to recognize the type and conformation of photobleached carotenoid molecules. Raman data revealed a nearly full photobleaching of the long-wavelength lutein molecules. The observed similar bleaching rate of the lutein molecules and the most-red shifted long-wavelength Chl a, located in the antenna membrane protein Lhca4, suggested that these molecules are located closely. Our results showed that the photobleached antenna pigments and especially luteins and the most long-wavelength absorbing chlorophylls are involved in photoprotection of PSI core complex.

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Section: Discussionsupporting

confidence: 93%

Selective Photobleaching of Chlorophylls and Carotenoids in Photosystem I Particles under High‐Light Treatment

Andreeva¹,

Abarova²,

Stoitchkova³

et al. 2007

Photochem & Photobiology

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“…The very similar k values for the Chla standard and the extracted Chls also indicates that Chlb is possibly also very sensitive to UV irradiation; consequently, Chla is the major contributor to the bleaching of the extracted Chls. 41 The calculated bleaching rate constants for the extracted chlorophylls, for all three UV-ranges in the two solvents and for all three concentrations (1.2×10 −6 , 1.2×10 −5 and 1.4×10 −4 mol dm −3 ) are shown in Table II. TABLE II.…”

Section: Resultsmentioning

confidence: 99%

Bleaching of chlorophylls by UV irradiation in vitro: The effects on chlorophyll organization in acetone and n-hexane

Zvezdanović¹,

Marković²

2008

J Serb Chem Soc

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The stability of chlorophylls toward UV irradiation was studied by Vis spectrophotometry in extracts containing mixtures of photosynthetic pigments in acetone and n-hexane. The chlorophylls underwent destruction (bleaching) obeying first-order kinetics. The bleaching was governed by three major factors: the energy input of the UV photons, the concentration of the chlorophylls and the polarity of the solvent, implying different molecular organizations of the chlorophylls in the two solvents.

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“…The concentration of pigments in liposomes is low (approximately 10 -6 M) and usually at this concentration, the monomeric form is dominant, even in non-polar solvents (Zvezdanović et al 2009). The comparison with the red band position of Chla, recorded in a native, highly-organized structure of pigment-protein complexes of isolated thylakoids -where Chls exist in aggregated form with the maximum at 679 nm (Santabarbara 2006) -is pleading also for the existence of pigments mainly in monomeric form in the lipid bilayers of liposomes.…”

Section: Discussionmentioning

confidence: 99%

Comparative spectroscopic studies on liposomes containing chlorophyll a and chlorophyllide a

Milenković¹,

Barbinta-Patrascu²,

Baranga³

et al. 2013

gpb

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Abstract. Chlorophyll a (Chla) and chlorophyllide a (Chlida) -a derivative of Chla, have been incorporated in the lipid bilayers of two types of liposomes, small unilamellar vesicles (SUV) and multilamelar vesicles (MLV). The objective of the present work was to compare the spectral behaviour of Chla and Chlida incorporated in the lipid bilayers and their sensing behaviour at molecular level. The VIS absorption and fluorescence emission presented differences depending on the type of liposomes and inserted pigment, reflecting the different localization of porphyrin macrocycle in the lipid moieties. The temperature dependence of emission anisotropy and fluorescence intensity, for both Chla and Chlida incorporated in DPPC SUV, revealed the presence of different lipid phases. The degree of incorporation of quercetin (QCT) in liposome membrane was studied by using Chla and Chlida as molecular sensors. The fluorescence polarisation data and the fluorescence quenching process provided arguments for the insertion of the QCT at the interface lipid/water, in the vicinity of lipid polar heads and porphyrin macrocycle. The phytyl chain of Chla penetrating in the hydrophobic core of the lipid bilayers is responsible for the observed differences among Chla and Chlida in sensing the lipid phase transition and the fluorescence quenching process induced by QCT.

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Limited sensitivity of pigment photo-oxidation in isolated thylakoids to singlet excited state quenching in photosystem II antenna

Cited by 24 publications

References 73 publications

Selective Photobleaching of Chlorophylls and Carotenoids in Photosystem I Particles under High‐Light Treatment

Selective Photobleaching of Chlorophylls and Carotenoids in Photosystem I Particles under High‐Light Treatment

Bleaching of chlorophylls by UV irradiation in vitro: The effects on chlorophyll organization in acetone and n-hexane

Comparative spectroscopic studies on liposomes containing chlorophyll a and chlorophyllide a

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