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Andrew A. Pascal
Université Paris-Saclay
36Publications
17H-index
2,072Citations
Publications 36
Newest
#1Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
#2Fei Li (CAS: Chinese Academy of Sciences)
Last.Bruno Robert (Université Paris-Saclay)H-Index: 47
view all 10 authors...
Abstract We describe a molecular mechanism tuning the functional properties of chlorophyll a (Chl-a) molecules in photosynthetic antenna proteins. Light-harvesting complexes from photosystem II in higher plants – specifically LHCII purified with α- or β-dodecyl-maltoside, along with CP29 – were probed by low-temperature absorption and resonance Raman spectroscopies. We show that hydrogen bonding to the conjugated keto carbonyl group of protein-bound Chl-a tunes the energy of its Soret and Qy abs...
#1Ana-Andreea ArteniH-Index: 1
#2Amy M. LaFountainH-Index: 12
Last.Andrew A. PascalH-Index: 17
view all 10 authors...
Carotenoid-containing oil droplets in the avian retina act as cut-off filters to enhance colour discrimination. We report a confocal resonance Raman investigation of the oil droplets of the domestic chicken, Gallus gallus domesticus. We show that all carotenoids present are in a constrained conformation, implying a locus in specific lipid binding sites. In addition, we provide proof of a recent conclusion that all carotenoid-containing droplets contain a mixture of all carotenoids present, rathe...
#1Simona Streckaite (Université Paris-Saclay)
#2Zdenko GardianRadek Litvõ ´ nDavid Bõ ´ na (Sewanee: The University of the South)H-Index: 10
Last.Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
view all 7 authors...
The soil chromophyte alga Xanthonema (X.) debile contains only non-carbonyl carotenoids and Chl-a. X. debile has an antenna system denoted Xanthophyte light-harvesting complex (XLH) that contains the carotenoids diadinoxanthin, heteroxanthin, and vaucheriaxanthin. The XLH pigment stoichiometry was calculated by chromatographic techniques and the pigment-binding structure studied by resonance Raman spectroscopy. The pigment ratio obtained by HPLC was found to be close to 8:1:2:1 Chl-a:heteroxanth...
#1Mahendra Kumar Shukla (Sewanee: The University of the South)H-Index: 3
#2Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
Last.Roman Sobotka (Sewanee: The University of the South)H-Index: 22
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Cyanobacteria possess a family of one-helix high-light-inducible proteins (HLIPs) that are widely viewed as ancestors of the light-harvesting antenna of plants and algae. HLIPs are essential for viability under various stress conditions, although their exact role is not fully understood. The unicellular cyanobacterium Synechocystis sp. PCC 6803 contains four HLIPs named HliA–D, and HliD has recently been isolated in a small protein complex and shown to bind chlorophyll and β-carotene. However, n...
#1Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
#2Kipras Redeckas (Vilnius University)H-Index: 6
Last.Bruno Robert (Université Paris-Saclay)H-Index: 47
view all 9 authors...
Transient absorption studies conducted on in vitro lycopene aggregates, as well as on lycopene crystalloids inside tomato chromoplasts, reveal the appearance of a long-lived excited state, which we unambiguously identified as lycopene triplet. These triplet states must be generated by singlet exciton fission, which occurs from the lycopene 2Ag state. This is the first time the singlet fission process has ever been shown to occur in a biological material. We propose that the formation of caroteno...
#1Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
#2Andrew A. Pascal (Université Paris-Saclay)H-Index: 17
Last.Bruno Robert (Université Paris-Saclay)H-Index: 47
view all 3 authors...
Carotenoids are among the most important organic compounds present in Nature and play several essential roles in biology. Their configuration is responsible for their specific photophysical properties, which can be tailored by changes in their molecular structure and in the surrounding environment. In this review, we give a general description of the main electronic and vibrational properties of carotenoids. In the first part, we describe how the electronic and vibrational properties are related...
#1Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
#2Radek LitvínH-Index: 11
Last.Bruno Robert (Université Paris-Saclay)H-Index: 47
view all 6 authors...
Resonance Raman spectroscopy was used to evaluate pigment-binding site properties in the violaxanthin–chlorophyll-a-binding protein (VCP) from Nannochloropsis oceanica. The pigments bound to this antenna protein are chlorophyll-a, violaxanthin, and vaucheriaxanthin. The molecular structures of bound Chl-a molecules are discussed with respect to those of the plant antenna proteins LHCII and CP29, the crystal structures of which are known. We show that three populations of carotenoid molecules are...
#1Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
#2Roman Sobotka (CAS: Academy of Sciences of the Czech Republic)H-Index: 22
Last.Bruno Robert (Université Paris-Saclay)H-Index: 47
view all 7 authors...
Abstract Cyanobacteria possess a family of one-helix high light-inducible proteins (Hlips) that are homologous to light-harvesting antenna of plants and algae. An Hlip protein, high light-inducible protein D (HliD) purified as a small complex with the Ycf39 protein is evaluated using resonance Raman spectroscopy. We show that the HliD binds two different β-carotenes, each present in two non-equivalent binding pockets with different conformations, having their (0,0) absorption maxima at 489 and 5...
#1Manuel J. Llansola-Portoles (Université Paris-Saclay)H-Index: 6
#2Chiasa Uragami (Université Paris-Saclay)H-Index: 6
Last.Bruno Robert (Université Paris-Saclay)H-Index: 47
view all 6 authors...
Abstract Resonance Raman spectroscopy was used to evaluate pigment structure in the FCP-like light-harvesting complex of Chromera velia ( Chromera light-harvesting complex or CLH). This antenna protein contains chlorophyll a , violaxanthin and a new isofucoxanthin-like carotenoid (called Ifx-l). We show that Ifx-l is present in two non-equivalent binding pockets with different conformations, having their (0,0) absorption maxima at 515 and 548 nm respectively. In this complex, only one violaxanth...
#1Elizabeth Kish (Université Paris-Saclay)H-Index: 5
#2Ke Wang (CAS: Chinese Academy of Sciences)H-Index: 6
Last.Chunhong Yang (CAS: Chinese Academy of Sciences)H-Index: 11
view all 7 authors...
Resonance Raman spectroscopy was used to evaluate the structure of light-harvesting chlorophyll (Chl) a/b complexes of photosystem II (LHCII), reconstituted from wild-type (WT) and mutant apoproteins over-expressed in Escherichia coli. The point mutations involved residue S123, exchanged for either P (S123P) or G (S123G). In all reconstituted proteins, lutein 2 displayed a distorted conformation, as it does in purified LHCII trimers. Reconstituted WT and S123G also exhibited a conformation of bo...
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