Engineering the sweet-tasting protein brazzein: analysis the effects on stability and sensory profile

International audience

Engineering the full sequence space of the sweet-tasting protein brazzein

International audience

Models and data analysis tools for the Solar Orbiter mission

All authors: Rouillard, A. P.; Pinto, R. F.; Vourlidas, A.; De Groof, A.; Thompson, W. T.; Bemporad, A.; Dolei, S.; Indurain, M.; Buchlin, E.; Sasso, C.; Spadaro, D.; Dalmasse, K.; Hirzberger, J.; Zouganelis, I.; Strugarek, A.; Brun, A. S.; Alexandre, M.; Berghmans, D.; Raouafi, N. E.; Wiegelmann, T.; Pagano, P.; Arge, C. N.; Nieves-Chinchilla, T.; Lavarra, M.; Poirier, N.; Amari, T.; Aran, A.; Andretta, V.; Antonucci, E.; Anastasiadis, A.; Auchère, F.; Bellot Rubio, L.; Nicula, B.; Bonnin, X.; Bouchemit, M.; Budnik, E.; Caminade, S.; Cecconi, B.; Carlyle, J.; Cernuda, I.; Davila, J. M.; Etesi, L.; Espinosa Lara, F.; Fedorov, A.; Fineschi, S.; Fludra, A.; Génot, V.; Georgoulis, M. K.; Gilbe…

Models and tools for territorial dynamic studies. Spatial dynamics of settlement patterns and natural resources : towards an integrated analysis over a long term, from Prehistory to the Middle Ages

International audience

ArchaeDyn. Dynamique spatiale du peuplement et ressources naturelles : vers une analyse intégrée dans le long terme, de la Préhistoire au Moyen Âge,. ACI Espaces et territoires (contrat ET28, 2005-2007)

Rapport de fin de contrat d'ACI

The time-space dynamics of agricultural areas from Antiquity to modern times (chapter 2)

International audience; This paper presents the analytical procedure developed within Workgroup 1 of the Archaedyn project. It examines the time-space dynamics of agrarian activities readable from the ancient field systems preserved by forest cover, and from off-site material interpreted as the remains of manuring practices. Using GIS and spatial statistics tools, we studied the structuring, intensity, durability and mobility of agrarian activities on different time scales.

Function of odorant-binding proteins in the Drosophila melanogaster chemoreception

National audience; Function of odorant-binding proteins in the Drosophila [i]melanogaster[/i] chemoreception. 18. rencontre du Club de neurobiologie des invertébrés

Overexpression of recombinant gurmarin secreted by the yeast Pichia pastoris

International audience

In-mouth metabolism and production of flavor sulfur compounds by oral microbiota enzymes

Flavor perception is the main factor in the acceptance of food. Cysteine derivatives are aroma precursors present in a number of plant-based foods (vegetables, fruits, as well as beverages such as wine). They have low odorant properties, but become odorant when metabolized into aroma sulfur compounds in the oral cavity. These sulfur compounds are sometimes associated with food aversion. Therefore, it is desirable to improve our knowledge of the entailed enzymatic mechanisms and design strategies aiming at controlling their release in-mouth. The involved enzymes are presumably carbon-sulfur lyases (C-S lyases) from the oral microbiota, but evidences are scarce. Recently, we showed that saliv…

Resolution of the X-ray structure of gurmarin: new insights into the molecular mechanism of sweet taste receptor inhibition

International audience

The implication of OBP28a in Drosophila melanogaster chemosensory perception

National audience; Chemoperception is critical for animals to detect nutritive food and avoid toxic compounds. As many other insects, Drosophila melanogaster uses various semiochemicals including pheromones and food volatiles to identify a suitable ecological niche and a mating partner. Chemosensory detection is mostly mediated by olfactory and gustatory systems involving several multigene chemoreceptor families. Volatile and non-volatile chemicals compounds entering into the sensory organ (sensillum) must be solubilized before being transported through the hydrophilic sensillum lymph bathing the chemosensory neurons. Such perireceptor events involve a family of soluble proteins named odora…

Strategy for recombinant expression of soluble functional N-terminal domain of human sweet taste receptor produced in Escherichia coli

International audience

Implication de l’OBP19b dans la perception gustative des acides aminés chez Drosophila melanogaster

National audience; La chimioperception est nécessaire à la détection des aliments nutritifs et à l’identification des composés toxiques, d’une niche écologique appropriée et des partenaires sexuels. Comme beaucoup d'autres insectes, la mouche du vinaigre, Drosophila melanogaster, possède des capacités chimiosensorielles performantes, la rendant très sensible en lui permettant de détecter et discriminer un large panel de substances chimiques. Chez la Drosophile, cette détection est réalisée par les systèmes chimiosensoriels gustatifs et olfactifs impliquant plusieurs familles de récepteurs. Les composés chimiques volatils et non volatils qui pénétrent les organes sensoriels (sensilles) doive…

The Crystal Structure of Gurmarin, a Sweet Taste–Suppressing Protein: Identification of the Amino Acid Residues Essential for Inhibition

International audience; Gurmarin is a highly specific sweet-taste suppressing protein in rodents that is isolated from the Indian plant Gymnemasylvestre. Gurmarin consists of 35 amino acid residues containing three intramolecular disulfide bridges that form a cystine knot. Here, we report the crystal structure of gurmarin at a 1.45 Å resolution and compare it with previously reported NMR solution structures. The atomic structure at this resolution allowed us to identify a very flexible region consisting of hydrophobic residues. Some of these amino acid residues had been identified as a putative binding site for the rat sweet taste receptor in a previous study. By combining alanine-scanning …

OBP19b is involved in the taste perception of amino acid in Drosophila melanogaster

Chemoperception plays a crucial role in the detection of nutritive food and avoidance of toxic compounds. It also allows animals to identify a suitable ecological niche and mating partners. As many other insects, Drosophila melanogaster possess a very sensitive chemosensory ability to detect and discriminate a wide panel of semiochemicals. Chemosensory detection is mostly mediated by olfactory and gustatory systems involving several multigene chemoreceptor families. Volatile and non-volatile chemicals compounds entering the sensory organ (sensillum) must be solubilized before being transported through the hydrophilic sensillum lymph bathing chemosensory receptors. Such “perireceptor events”…

Purification, biophysical characterization and first crystallization trials of the ligand-binding domain of the human T1R3 sweet taste receptor

International audience

Models and tools for territorial dynamic studies (chapter 1)

As part of the ArchaeDyn project, a workgroup was formed to coordinate the development, implementation and application of methods and tools for spatial analysis. The workgroup's activities were directed at various problems. The first was to construct a grid common to all the workgroups and to homogenize the study areas used by the different workgroups in their databases. The 'confidence maps' method was suggested for assessing the quality and quantity of information inventoried in the databases. Confidence maps are produced from representation and reliability maps by simple map algebra and they can be considered as 'masks' for interpreting spatial analysis results. Finally, the research tea…

Archaedyn - Workshop 1 - The dynamics of agricultural areas in the long term

Document destiné à être publié dans l’ouvrage ARCHAEDYN. Dynamique spatiale des territoires de la Préhistoire au Moyen Âge, auteurs : BERTONCELLO, F., FAVORY, F., GAUTHIER, E., GEORGES-LEROY, M., NUNINGER, L., POIRIER, N., WELLER, O., à paraître aux PUFC, Besançon, collection Cahiers de la MSHE, série Dynamiques territoriales.

Formalization of scientific process and conceptual modelling for the study of territorial and products distribution dynamics (ArchaeDyn II programme)

International audience; The ArchaeDyn team has investigated territorial dynamics by comparing areas over long time spans between the Neolithic and Modern times. Datasets on various themes have been shared and indicators and analytical models produced. This paper presents both the formalization of the scientific process used in the ArchaeDyn programme and a conceptual model of the systems and components so that synchronic and diachronic comparisons can be made. The aim is to clarify the transition from an archaeological feature (a site or an artefact) or a recording unit (survey area) as the input, to the characterization of spaces describing a system as the output. The approach is described…

Optimization of the production of recombinant brazzein secreted by the yeast pichia pastoris

International audience

Metabolism of flavor sulfur precursors by the oral microbiota

Purification and characterization of recombinant gurmarin secreted by the yeast Pichia pastoris

National audience

Archaedyn - Workshop 1 - The dynamics of agricultural areas in the long term

The X-ray structure of gurmarin provide new insights into amino acid residues essential for inhibition of the rat sweet taste receptor

International audience; Gurmarin is a polypeptide isolated from the Indian plant Gymnema sylvestre, which specifically suppresses sweet taste in rodents without affecting responses to other basic taste stimuli, such as HCl, NaCl, and quinine. Although the exact mechanism of gurmarin inhibition is not known, it has been shown that gurmarin acts via the T1R2/T1R3 sweet taste receptor. The gurmarin molecule is made of 35 amino-acid residues and three intramolecular disulfide bridges. We report herein the 1.45 Å X-ray structure of gurmarin heterologously produced using the yeast Pichia pastoris. The structure revealed a typical knottin fold, which is compared with previously reported NMR soluti…