82 research outputs found

    Tempo and drivers of plant diversification in the European mountain system

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    There is still limited consensus on the evolutionary history of species-rich temperate alpine floras due to a lack of comparable and high-quality phylogenetic data covering multiple plant lineages. Here we reconstructed when and how European alpine plant lineages diversified, i.e., the tempo and drivers of speciation events. We performed full-plastome phylogenomics and used multi-clade comparative models applied to six representative angiosperm lineages that have diversified in European mountains (212 sampled species, 251 ingroup species total). Diversification rates remained surprisingly steady for most clades, even during the Pleistocene, with speciation events being mostly driven by geographic divergence and bedrock shifts. Interestingly, we inferred asymmetrical historical migration rates from siliceous to calcareous bedrocks, and from higher to lower elevations, likely due to repeated shrinkage and expansion of high elevation habitats during the Pleistocene. This may have buffered climate-related extinctions, but prevented speciation along elevation gradients as often documented for tropical alpine floras

    Modalités de recrutement des sujets dans la recherche en pédiatrie : étude prospective multicentrique

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    Contexte. - Une enquĂȘte qualitative exploratoire a montrĂ© que le nombre de patients Ă©ligibles et sollicitĂ©s dans les essais en pĂ©diatrie Ă©tait peu objectivĂ© ainsi que les refus. Objectif. - Estimer le nombre de refus de participation des familles dans les essais en pĂ©diatrie et lier le taux de refus aux caractĂ©ristiques protocole, investigateur et patients. MatĂ©riel et mĂ©thodes. - Étude prospective multicentrique inter-CIC (rĂ©seau pĂ©diatrique) d'une cohorte de protocoles. Pour chaque sollicitation Ă  participer, des fiches patient, investigateur et protocole Ă©taient remplies. RĂ©sultats. - L'Ă©tude a Ă©tĂ© rĂ©alisĂ©e de dĂ©cembre 2005 Ă  septembre 2007 sur quatre centres et a inclus 45 protocoles : 32 Ă  promotion industrielle, 36 multicentriques, 19 essais cliniques, 33 avec prises de sang et six avec examens invasifs, 26 avec des dĂ©placements spĂ©cifiques et 14 des hospitalisations supplĂ©mentaires. Sur ces protocoles, 170 investigateurs Ă©taient rĂ©fĂ©rencĂ©s comme recruteurs et 86 (51 %) ont rĂ©pondu au questionnaire : Ăąge mĂ©dian 42 ans, sex-ratio de 1, 13 sont investigateurs principal, 32 responsables pour le CIC et 50 investigateurs associĂ©s, 20 percevaient une rĂ©tribution versĂ©e au service dans 80 % des cas. La charge de travail mĂ©diane par investigateur Ă©tait d'une heure par inclusion et 67 (78 %) bĂ©nĂ©ficiaient d'une aide d'une TEC. Au total, 1022 sollicitations ont Ă©tĂ© rĂ©alisĂ©es sur 36 protocoles (neuf protocoles n'ayant eu aucune sollicitation) et 334 refus (33 %) ont Ă©tĂ© enregistrĂ©s soit une mĂ©diane de 12 % (Q1Q3 : 0-28 %) de refus par protocole. Parmi les 36 protocoles, 16 n'ont enregistrĂ© aucun refus, reprĂ©sentant 147 sollicitations et les 20 autres protocoles ont eu un taux moyen de 38 % de refus. L'analyse explicative est en cours. Conclusion. - Le taux de refus de 12 % n'est pas diffĂ©rent de celui des essais adultes et semble dĂ©pendant du type d'Ă©tude. L'absence de sollicitation concerne 20 % des Ă©tudes

    A new 3MW ECRH system at 105 GHz for WEST

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    The aim of the WEST experiments is to master long plasma pulses (1000s) and expose ITER-like tungsten wall to deposited heat fluxes up to 10 MW/m2^2. To increase the margin to reach the H-Mode and to control W-impurities in the plasma, the installation of an upgraded ECRH heating system, with a gyrotron performance of 1MW/1000s per unit, is planned in 2023. With the modifications of Tore Supra to WEST, simulations at a magnetic field B0_0∌3.7T and a central density ne0_{e0}∌6 × 1019^{19} m−3^{−3} show that the optimal frequency for central absorption is 105 GHz. For this purpose, a 105 GHz/1MW gyrotron (TH1511) has been designed at KIT in 2021, based on the technological design of the 140 GHz/1.5 MW (TH1507U) gyrotron for W7-X. Currently, three units are under fabrication at THALES. In the first phase of the project, some of the previous Tore Supra Electron Cyclotron (EC) system components will be re-installed and re-used whenever possible. This paper describes the studies performed to adapt the new ECRH system to 105 GHz and the status of the modifications necessary to re-start the system with a challenging schedule

    Incidence of Sarcoma Histotypes and Molecular Subtypes in a Prospective Epidemiological Study with Central Pathology Review and Molecular Testing

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    International audienceBACKGROUND: The exact overall incidence of sarcoma and sarcoma subtypes is not known. The objective of the present population-based study was to determine this incidence in a European region (Rhone-Alpes) of six million inhabitants, based on a central pathological review of the cases. METHODOLOGY/PRINCIPAL FINDINGS: From March 2005 to February 2007, pathology reports and tumor blocks were prospectively collected from the 158 pathologists of the Rhone-Alpes region. All diagnosed or suspected cases of sarcoma were collected, reviewed centrally, examined for molecular alterations and classified according to the 2002 World Health Organization classification. Of the 1287 patients screened during the study period, 748 met the criteria for inclusion in the study. The overall crude and world age-standardized incidence rates were respectively 6.2 and 4.8 per 100,000/year. Incidence rates for soft tissue, visceral and bone sarcomas were respectively 3.6, 2.0 and 0.6 per 100,000. The most frequent histological subtypes were gastrointestinal stromal tumor (18%; 1.1/100,000), unclassified sarcoma (16%; 1/100,000), liposarcoma (15%; 0.9/100,000) and leiomyosarcoma (11%; 0.7/100,000). CONCLUSIONS/SIGNIFICANCE: The observed incidence of sarcomas was higher than expected. This study is the first detailed investigation of the crude incidence of histological and molecular subtypes of sarcomas

    Community-Level Responses to Iron Availability in Open Ocean Plankton Ecosystems

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    Predicting responses of plankton to variations in essential nutrients is hampered by limited in situ measurements, a poor understanding of community composition, and the lack of reference gene catalogs for key taxa. Iron is a key driver of plankton dynamics and, therefore, of global biogeochemical cycles and climate. To assess the impact of iron availability on plankton communities, we explored the comprehensive bio-oceanographic and bio-omics data sets from Tara Oceans in the context of the iron products from two state-of-the-art global scale biogeochemical models. We obtained novel information about adaptation and acclimation toward iron in a range of phytoplankton, including picocyanobacteria and diatoms, and identified whole subcommunities covarying with iron. Many of the observed global patterns were recapitulated in the Marquesas archipelago, where frequent plankton blooms are believed to be caused by natural iron fertilization, although they are not captured in large-scale biogeochemical models. This work provides a proof of concept that integrative analyses, spanning from genes to ecosystems and viruses to zooplankton, can disentangle the complexity of plankton communities and can lead to more accurate formulations of resource bioavailability in biogeochemical models, thus improving our understanding of plankton resilience in a changing environment

    Convergent genetic and expression data implicate immunity in Alzheimer's disease

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    Background Late–onset Alzheimer's disease (AD) is heritable with 20 genes showing genome wide association in the International Genomics of Alzheimer's Project (IGAP). To identify the biology underlying the disease we extended these genetic data in a pathway analysis. Methods The ALIGATOR and GSEA algorithms were used in the IGAP data to identify associated functional pathways and correlated gene expression networks in human brain. Results ALIGATOR identified an excess of curated biological pathways showing enrichment of association. Enriched areas of biology included the immune response (p = 3.27×10-12 after multiple testing correction for pathways), regulation of endocytosis (p = 1.31×10-11), cholesterol transport (p = 2.96 × 10-9) and proteasome-ubiquitin activity (p = 1.34×10-6). Correlated gene expression analysis identified four significant network modules, all related to the immune response (corrected p 0.002 – 0.05). Conclusions The immune response, regulation of endocytosis, cholesterol transport and protein ubiquitination represent prime targets for AD therapeutics

    Etude du mĂ©canisme catalytique de la lipoxygenase 1 d’olive

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    Lipoxygenases (LOXs, EC 1.13.11.12) are widespread dioxygenases containing a non heminic iron atom. In plants, LOXs are at the beginning of a metabolic pathway involved in several physiological processes and in the response to environmental stress. A LOX initiates the pathway, catalyzing a regiospecific and stereospecific insertion of oxygen on the pentadiene system of a free polyunsaturated fatty acid (linoleic or linolenic acid) to form fatty acid hydroperoxides.An olive lipoxygenase called olive LOX1, cloned at laboratory, has been expressed in E. coli strain and purified. Olive LOX1 produces 9S-hydroperoxides of and 13R-hydroperoxides from linoleic acid, in a ratio of 2:1, being the only plant LOX to produce R-hydroperoxides described to date. From the currently known models explaining the control of reactional specificity, none can be applied to olive LOX1. A three-dimensional model has been built by homology modeling to understand the catalytic mechanism of olive LOX1. Site-directed mutagenesis experiments have been used to modify two residues of particular interest, the phenylalanine 277 and the tyrosine 280, allowing us to point the active site entrance near these two residues. Other residues of interest have been modified to study their role in the catalytic mechanism and the reactional specificity of olive LOX1. The results have led us to propose a first hypothesis for the reactional mechanism of this enzyme: the substrate could enter into the active site with its carboxylate-end first, and could be stabilized in the active site by hydrophobic side chains of several residues. A channel could bring oxygen into the active site at a position near the side chain of the leucine 579 residue, this one targeting oxygen onto the pentadiene system of the substrate, controlling by this way the reactional specificity of olive LOX1.LOX are involved in oxylipins synthesis. Arabidopsides are a class of oxylipins found in Arabidopsis that could be produced by action of a 13-LOX on galactolipids, which carry esterified fatty acids. Activity of soybean 13-LOX, olive 9/13-LOX1 and potato 9-LOX has been investigated with galactolipids. A low activity was measured when soybean and olive LOXs were used. Activity was far more important when potato LOX was used. These results suggest that LOX can act on esterified fatty acids, especially galactolipids.Les lipoxygĂ©nases (LOX, EC 1.13.11.12) sont des dioxygĂ©nases Ă  fer non hĂ©minique trĂšs rĂ©pandues. Chez les vĂ©gĂ©taux, ces enzymes sont Ă  l’origine d’une voie mĂ©tabolique impliquĂ©e dans de nombreux processus physiologiques, mais aussi dans la rĂ©ponse Ă  un stress environnemental. La LOX initie la voie en catalysant l’incorporation rĂ©giospĂ©cifique et stĂ©rĂ©ospĂ©cifique de dioxygĂšne sur le systĂšme pentadiĂ©nique d’un acide gras libre polyinsaturĂ© (prĂ©fĂ©rentiellement l’acide linolĂ©ique ou l’acide linolĂ©nique) pour gĂ©nĂ©rer un hydroperoxyde d’acide gras.Une lipoxygĂ©nase d’olive appelĂ©e LOX1, clonĂ©e au laboratoire, a Ă©tĂ© exprimĂ©e chez E. coli et purifiĂ©e. Elle produit Ă  partir d’acide linolĂ©ique des hydroperoxydes de configuration 9S et 13R dans des proportions 2:1. Elle est la seule lipoxygĂ©nase vĂ©gĂ©tale dĂ©crite Ă  ce jour produisant des hydroperoxydes de configuration R. Les modĂšles proposĂ©s pour expliquer le contrĂŽle de la spĂ©cificitĂ© rĂ©actionnelle des LOX ne s’appliquent pas Ă  la LOX1 d’olive. Afin de mieux comprendre son mĂ©canisme de fonctionnement, un modĂšle tridimensionnel de la LOX1 d’olive a Ă©tĂ© construit. La modification par mutagĂ©nĂšse dirigĂ©e de deux rĂ©sidus particuliers, la phĂ©nylalanine 277 et la tyrosine 280, a permis d’identifier l’entrĂ©e du site actif de la LOX1 d’olive. D’autres rĂ©sidus particuliers ont Ă©tĂ© modifiĂ©s par mutagĂ©nĂšse dirigĂ©e afin d’étudier leur rĂŽle dans le mĂ©canisme catalytique et le contrĂŽle de la spĂ©cificitĂ© rĂ©actionnelle de la LOX1 d’olive. L’analyse globale des rĂ©sultats obtenus a permis de proposer une premiĂšre hypothĂšse quant au fonctionnement de cette enzyme : le substrat pĂ©nĂštrerait dans le site actif de la LOX1 d’olive par son extrĂ©mitĂ© carboxylate, et serait stabilisĂ© dans le site actif par plusieurs rĂ©sidus hydrophobes. Un canal pourrait cibler l’oxygĂšne dans le site actif par l’intermĂ©diaire du rĂ©sidu L579 sur le systĂšme pentadiĂ©nique du substrat, contrĂŽlant de cette maniĂšre la spĂ©cificitĂ© rĂ©actionnelle de la LOX1 d’olive.Par ailleurs, des oxylipines retrouvĂ©es chez Arabidopsis, appelĂ©es arabidopsides, pourraient ĂȘtre formĂ©es par action directe d’une 13-LOX sur des acides gras estĂ©rifiĂ©s des galactolipides. L’action de la 13-LOX1 de soja, la 9/13-LOX1 d’olive et la 9-LOX de pomme de terre a Ă©tĂ© testĂ©e avec des galactolipides. Une faible activitĂ© a Ă©tĂ© mesurĂ©e avec la 13-LOX1 de soja et la 9/13-LOX1 d’olive. Une activitĂ© plus importante a Ă©tĂ© mesurĂ©e avec la 9-LOX de pomme de terre. Ces rĂ©sultats suggĂšrent que l’action des LOX est possible sur des acides gras estĂ©rifiĂ©s des galactolipides

    Etude du mĂ©canisme catalytique de la lipoxygenase 1 d’olive

    No full text
    Lipoxygenases (LOXs, EC 1.13.11.12) are widespread dioxygenases containing a non heminic iron atom. In plants, LOXs are at the beginning of a metabolic pathway involved in several physiological processes and in the response to environmental stress. A LOX initiates the pathway, catalyzing a regiospecific and stereospecific insertion of oxygen on the pentadiene system of a free polyunsaturated fatty acid (linoleic or linolenic acid) to form fatty acid hydroperoxides.An olive lipoxygenase called olive LOX1, cloned at laboratory, has been expressed in E. coli strain and purified. Olive LOX1 produces 9S-hydroperoxides of and 13R-hydroperoxides from linoleic acid, in a ratio of 2:1, being the only plant LOX to produce R-hydroperoxides described to date. From the currently known models explaining the control of reactional specificity, none can be applied to olive LOX1. A three-dimensional model has been built by homology modeling to understand the catalytic mechanism of olive LOX1. Site-directed mutagenesis experiments have been used to modify two residues of particular interest, the phenylalanine 277 and the tyrosine 280, allowing us to point the active site entrance near these two residues. Other residues of interest have been modified to study their role in the catalytic mechanism and the reactional specificity of olive LOX1. The results have led us to propose a first hypothesis for the reactional mechanism of this enzyme: the substrate could enter into the active site with its carboxylate-end first, and could be stabilized in the active site by hydrophobic side chains of several residues. A channel could bring oxygen into the active site at a position near the side chain of the leucine 579 residue, this one targeting oxygen onto the pentadiene system of the substrate, controlling by this way the reactional specificity of olive LOX1.LOX are involved in oxylipins synthesis. Arabidopsides are a class of oxylipins found in Arabidopsis that could be produced by action of a 13-LOX on galactolipids, which carry esterified fatty acids. Activity of soybean 13-LOX, olive 9/13-LOX1 and potato 9-LOX has been investigated with galactolipids. A low activity was measured when soybean and olive LOXs were used. Activity was far more important when potato LOX was used. These results suggest that LOX can act on esterified fatty acids, especially galactolipids.Les lipoxygĂ©nases (LOX, EC 1.13.11.12) sont des dioxygĂ©nases Ă  fer non hĂ©minique trĂšs rĂ©pandues. Chez les vĂ©gĂ©taux, ces enzymes sont Ă  l’origine d’une voie mĂ©tabolique impliquĂ©e dans de nombreux processus physiologiques, mais aussi dans la rĂ©ponse Ă  un stress environnemental. La LOX initie la voie en catalysant l’incorporation rĂ©giospĂ©cifique et stĂ©rĂ©ospĂ©cifique de dioxygĂšne sur le systĂšme pentadiĂ©nique d’un acide gras libre polyinsaturĂ© (prĂ©fĂ©rentiellement l’acide linolĂ©ique ou l’acide linolĂ©nique) pour gĂ©nĂ©rer un hydroperoxyde d’acide gras.Une lipoxygĂ©nase d’olive appelĂ©e LOX1, clonĂ©e au laboratoire, a Ă©tĂ© exprimĂ©e chez E. coli et purifiĂ©e. Elle produit Ă  partir d’acide linolĂ©ique des hydroperoxydes de configuration 9S et 13R dans des proportions 2:1. Elle est la seule lipoxygĂ©nase vĂ©gĂ©tale dĂ©crite Ă  ce jour produisant des hydroperoxydes de configuration R. Les modĂšles proposĂ©s pour expliquer le contrĂŽle de la spĂ©cificitĂ© rĂ©actionnelle des LOX ne s’appliquent pas Ă  la LOX1 d’olive. Afin de mieux comprendre son mĂ©canisme de fonctionnement, un modĂšle tridimensionnel de la LOX1 d’olive a Ă©tĂ© construit. La modification par mutagĂ©nĂšse dirigĂ©e de deux rĂ©sidus particuliers, la phĂ©nylalanine 277 et la tyrosine 280, a permis d’identifier l’entrĂ©e du site actif de la LOX1 d’olive. D’autres rĂ©sidus particuliers ont Ă©tĂ© modifiĂ©s par mutagĂ©nĂšse dirigĂ©e afin d’étudier leur rĂŽle dans le mĂ©canisme catalytique et le contrĂŽle de la spĂ©cificitĂ© rĂ©actionnelle de la LOX1 d’olive. L’analyse globale des rĂ©sultats obtenus a permis de proposer une premiĂšre hypothĂšse quant au fonctionnement de cette enzyme : le substrat pĂ©nĂštrerait dans le site actif de la LOX1 d’olive par son extrĂ©mitĂ© carboxylate, et serait stabilisĂ© dans le site actif par plusieurs rĂ©sidus hydrophobes. Un canal pourrait cibler l’oxygĂšne dans le site actif par l’intermĂ©diaire du rĂ©sidu L579 sur le systĂšme pentadiĂ©nique du substrat, contrĂŽlant de cette maniĂšre la spĂ©cificitĂ© rĂ©actionnelle de la LOX1 d’olive.Par ailleurs, des oxylipines retrouvĂ©es chez Arabidopsis, appelĂ©es arabidopsides, pourraient ĂȘtre formĂ©es par action directe d’une 13-LOX sur des acides gras estĂ©rifiĂ©s des galactolipides. L’action de la 13-LOX1 de soja, la 9/13-LOX1 d’olive et la 9-LOX de pomme de terre a Ă©tĂ© testĂ©e avec des galactolipides. Une faible activitĂ© a Ă©tĂ© mesurĂ©e avec la 13-LOX1 de soja et la 9/13-LOX1 d’olive. Une activitĂ© plus importante a Ă©tĂ© mesurĂ©e avec la 9-LOX de pomme de terre. Ces rĂ©sultats suggĂšrent que l’action des LOX est possible sur des acides gras estĂ©rifiĂ©s des galactolipides

    Study of the catalytic mechanism of lipoxygenase 1 Olive

    No full text
    Les lipoxygĂ©nases (LOX, EC 1.13.11.12) sont des dioxygĂ©nases Ă  fer non hĂ©minique trĂšs rĂ©pandues. Chez les vĂ©gĂ©taux, ces enzymes sont Ă  l’origine d’une voie mĂ©tabolique impliquĂ©e dans de nombreux processus physiologiques, mais aussi dans la rĂ©ponse Ă  un stress environnemental. La LOX initie la voie en catalysant l’incorporation rĂ©giospĂ©cifique et stĂ©rĂ©ospĂ©cifique de dioxygĂšne sur le systĂšme pentadiĂ©nique d’un acide gras libre polyinsaturĂ© (prĂ©fĂ©rentiellement l’acide linolĂ©ique ou l’acide linolĂ©nique) pour gĂ©nĂ©rer un hydroperoxyde d’acide gras.Une lipoxygĂ©nase d’olive appelĂ©e LOX1, clonĂ©e au laboratoire, a Ă©tĂ© exprimĂ©e chez E. coli et purifiĂ©e. Elle produit Ă  partir d’acide linolĂ©ique des hydroperoxydes de configuration 9S et 13R dans des proportions 2:1. Elle est la seule lipoxygĂ©nase vĂ©gĂ©tale dĂ©crite Ă  ce jour produisant des hydroperoxydes de configuration R. Les modĂšles proposĂ©s pour expliquer le contrĂŽle de la spĂ©cificitĂ© rĂ©actionnelle des LOX ne s’appliquent pas Ă  la LOX1 d’olive. Afin de mieux comprendre son mĂ©canisme de fonctionnement, un modĂšle tridimensionnel de la LOX1 d’olive a Ă©tĂ© construit. La modification par mutagĂ©nĂšse dirigĂ©e de deux rĂ©sidus particuliers, la phĂ©nylalanine 277 et la tyrosine 280, a permis d’identifier l’entrĂ©e du site actif de la LOX1 d’olive. D’autres rĂ©sidus particuliers ont Ă©tĂ© modifiĂ©s par mutagĂ©nĂšse dirigĂ©e afin d’étudier leur rĂŽle dans le mĂ©canisme catalytique et le contrĂŽle de la spĂ©cificitĂ© rĂ©actionnelle de la LOX1 d’olive. L’analyse globale des rĂ©sultats obtenus a permis de proposer une premiĂšre hypothĂšse quant au fonctionnement de cette enzyme : le substrat pĂ©nĂštrerait dans le site actif de la LOX1 d’olive par son extrĂ©mitĂ© carboxylate, et serait stabilisĂ© dans le site actif par plusieurs rĂ©sidus hydrophobes. Un canal pourrait cibler l’oxygĂšne dans le site actif par l’intermĂ©diaire du rĂ©sidu L579 sur le systĂšme pentadiĂ©nique du substrat, contrĂŽlant de cette maniĂšre la spĂ©cificitĂ© rĂ©actionnelle de la LOX1 d’olive.Par ailleurs, des oxylipines retrouvĂ©es chez Arabidopsis, appelĂ©es arabidopsides, pourraient ĂȘtre formĂ©es par action directe d’une 13-LOX sur des acides gras estĂ©rifiĂ©s des galactolipides. L’action de la 13-LOX1 de soja, la 9/13-LOX1 d’olive et la 9-LOX de pomme de terre a Ă©tĂ© testĂ©e avec des galactolipides. Une faible activitĂ© a Ă©tĂ© mesurĂ©e avec la 13-LOX1 de soja et la 9/13-LOX1 d’olive. Une activitĂ© plus importante a Ă©tĂ© mesurĂ©e avec la 9-LOX de pomme de terre. Ces rĂ©sultats suggĂšrent que l’action des LOX est possible sur des acides gras estĂ©rifiĂ©s des galactolipides.Lipoxygenases (LOXs, EC 1.13.11.12) are widespread dioxygenases containing a non heminic iron atom. In plants, LOXs are at the beginning of a metabolic pathway involved in several physiological processes and in the response to environmental stress. A LOX initiates the pathway, catalyzing a regiospecific and stereospecific insertion of oxygen on the pentadiene system of a free polyunsaturated fatty acid (linoleic or linolenic acid) to form fatty acid hydroperoxides.An olive lipoxygenase called olive LOX1, cloned at laboratory, has been expressed in E. coli strain and purified. Olive LOX1 produces 9S-hydroperoxides of and 13R-hydroperoxides from linoleic acid, in a ratio of 2:1, being the only plant LOX to produce R-hydroperoxides described to date. From the currently known models explaining the control of reactional specificity, none can be applied to olive LOX1. A three-dimensional model has been built by homology modeling to understand the catalytic mechanism of olive LOX1. Site-directed mutagenesis experiments have been used to modify two residues of particular interest, the phenylalanine 277 and the tyrosine 280, allowing us to point the active site entrance near these two residues. Other residues of interest have been modified to study their role in the catalytic mechanism and the reactional specificity of olive LOX1. The results have led us to propose a first hypothesis for the reactional mechanism of this enzyme: the substrate could enter into the active site with its carboxylate-end first, and could be stabilized in the active site by hydrophobic side chains of several residues. A channel could bring oxygen into the active site at a position near the side chain of the leucine 579 residue, this one targeting oxygen onto the pentadiene system of the substrate, controlling by this way the reactional specificity of olive LOX1.LOX are involved in oxylipins synthesis. Arabidopsides are a class of oxylipins found in Arabidopsis that could be produced by action of a 13-LOX on galactolipids, which carry esterified fatty acids. Activity of soybean 13-LOX, olive 9/13-LOX1 and potato 9-LOX has been investigated with galactolipids. A low activity was measured when soybean and olive LOXs were used. Activity was far more important when potato LOX was used. These results suggest that LOX can act on esterified fatty acids, especially galactolipids
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