Search results for "Protéine"
showing 10 items of 106 documents
Characterisation of NO synthases from the alga Klebsormidium nitens
2022
Nitric oxide (NO) is an important cellular signaling molecule regulating various physiological processes, in both animals and plants. In animals, NO synthesis is mainly catalyzed by NO synthase (NOS) enzymes. In plants, NOS-like activities sensitive to mammalian NOS inhibitors have been measured, although no sequences encoding mammalian NOS have been found in land plants. Interestingly, we identified NOS-like sequences in about twenty algae species. These latter include the filamentous Charophyta green algae Klebsormidium nitens, a biological model to study the early transition step from aquatic algae to land plants. Currently, two NOS were identified in K. nitens genome: i) KnNOS1 which po…
Protéines végétales, ces mal-aimées
2019
Dans une autre expérience, les chercheurs de l’Inra ont demandé à 120 participants adultes d’imaginer des repas à partir d’images de différents produits. Ils devaient ainsi proposer un menu pour diverses occasions : un repas à la maison, un repas au restaurant, un repas chic, un repas pour un invité végétarien... Les scientifiques ont alors remarqué que la viande était le premier produit alimentaire choisi, ce qui indique que la construction du repas par des consommateurs non-végétariens se fait autour de cet aliment. Le choix le plus commun était l’association viande, féculents, légumes. Les légumes secs étaient très rarement choisis et lorsqu’ils l’étaient, c’était le plus souvent associé…
Contes et légendes des produits carnés
2019
Dans la plupart des ménages, la viande trône au centre des assiettes. Le geste naturel, lors de la préparation des aliments, est d’apprêter un morceau de viande quel que soit son accompagnement. Pour comprendre les scripts sociaux derrière ces comportements, les chercheurs de l’Inra ont réalisé des interviews approfondies avec 27 mères ayant des enfants âgés de 6 à 11 ans. Un choix qui s’explique par ce chiffre : dans 80 % des ménages, ce sont les mères de famille qui s’occupent des achats et de la préparation des repas. Cette étude n’est pas un sondage : elle n’est pas, bien entendu, représentative de la population française. Ceci étant, elle permet d’identifier certaines visions communes …
Bien manger, ça s'apprend / A l'école du bien manger / Dijon alimentation durable 2030
2019
BIEN MANGER, ÇA S’APPREND « On acquiert son répertoire alimentaire un peu comme on apprend sa langue maternelle », lance Sophie Nicklaus, chercheuse à l’Inra au Centre des sciences du goût et de l’alimentation. « C’est par l’exposition répétée à des aliments variés que l’on forme ses habitudes, sans même y prêter attention ». La petite enfance est un moment clé pour l’alimentation. Une période matrice où se forment nos préférences. Les études montrent que plus l’enfant a l’occasion de goûter de nouveaux aliments, plus ceux qu’il appréciera seront nombreux. Comme pour tout apprentissage, répéter, insister, recommencer sont les maîtres-mots, en particulier lors de l’introduction des légumes. …
Characterization of the ligands for the human umami taste receptor
2017
National audience; Among our basics senses, taste and our gustatory system allow us to perceive and recognize essential chemical nutrients present in food. Human can detect and discriminate five basics taste (sweet, bitter, sour, salty and umami) and recent studies proposed a sixth taste for fat. The umami taste is described as a « savory » sensation elicited mainly by L-amino acids and is thought to serve as an indicator of protein rich foods and promote feeding.The umami taste receptor is a heterodimeric receptor composed of the T1R1 and T1R3 subunits. These subunits belong to the family class C G protein-coupled receptors (GPCRs) and are constituted by a large N-terminal domain (NTD) lin…
Dynamics and toxicity of proteins with a high homology of sequences: approach by molecular dynamics and ab-initio calculations
2008
The elucidation of the structure and the biological function of proteins is a major stake for its implications in the biomedical research as well as in biotechnologies. In addition, there is a glass or dynamical transition for the proteins which occurs at around 200K: it has been observed by Neutron Scattering, X-ray diffraction and Mossbauer spectroscopy for different proteins. Above the transition temperature, the biological function is activated as the protein may diffuse between conformational sub-states. The microscopic origin of this transition is still debated in spite of significant advances in recent years showing the significant role of hydration. By using all-atoms classical mole…
Regulation of the activity of the Cholesteryl Ester Tranfer Protein (CETP) : electrostatics interactions with carboxylic derivatives (Non Esterified …
1997
In human plasma, the cholesteryl ester transfer protein (CETP) plays a key role in lipoprotein metabolism by promoting the net mass transfer of cholesteryl esters from HDL towards apoB-containing lipoproteins, and the transfer of triglycerides from VLDL towards HDL and LDL. Thus CETP arises as a potentially important factor in plasma lipoproteins metabolism, a statement which raised a considerable interest in identifying the factors which may regulate CETP activity.In our in vitro studies, we demonstrated that amphipathic molecules (non esterified fatty acids and retinoic acids) constituted of one carboxylic head group and one hydrophobic carbon chain are able to increase the cholesteryl es…
Function of odorant-binding proteins in the Drosophila melanogaster chemoreception
2017
National audience; Function of odorant-binding proteins in the Drosophila [i]melanogaster[/i] chemoreception. 18. rencontre du Club de neurobiologie des invertébrés
L'accumulation des protéines dans les graines de légumineuses
2017
The agroecological benefits of legumes and the renewed interest in the consumption of vegetable proteins stimulate researches on cognitive and applied aspects of seed biology aiming at optimizing protein composition of legume seeds. This article presents the state of knowledge on the genetic and environmental control of the accumulation of major proteins found in legume seeds, with a view to developing varieties with improved nutritional seed quality. It also shows how high-throughput genomics and post-genomics data, along with translational research aiming at transferring knowledge between model and crop species, can accelerate the identification of genes controlling the accumulation of st…
Isolement et caractérisation de saponosides extraits de deux plantes médicinales : Cyclamen africanum, Zygophyllum cornutum et évalution de leur acti…
2014
The appearance of several diseases, such as cancer, diabetes, high blood pressure and spread of infections mutagenic virus type can be linked to the quality and lifestyle that we lead today. Indeed, several studies on the factors triggering these so-called "morbid" long-or short-term illnesses are related to stress and quality of food consumed, whether of plant and animal origin. These diseases are becoming a common occurrence, they affect different races and all classes of society. According ethnobotanical research, naturally occurring substances, allowed civilizations to survive deadly diseases. For example, we thus find references to periods of malarial fever in China and one of the symp…