Taste receptors in oral and extraoral tissues: role in nutrient and metabolic sensing

Characterization of taste compounds: chemical structures and sensory properties

Characterization of taste compounds: chemical structures and sensory properties

Characterization of rat glutathione transferases in olfactory epithelium and mucus

International audience; The olfactory epithelium is continuously exposed to exogenous chemicals, including odorants. During the past decade, the enzymes surrounding the olfactory receptors have been shown to make an important contribution to the process of olfaction. Mammalian xenobiotic metabolizing enzymes, such as cytochrome P450, esterases and glutathione transferases (GSTs), have been shown to participate in odorant clearance from the olfactory receptor environment, consequently contributing to the maintenance of sensitivity toward odorants. GSTs have previously been shown to be involved in numerous physiological processes, including detoxification, steroid hormone biosynthesis, and am…

Identification of a lysyl residue defining the binding specificity of a human odorant-binding protein

International audience

Highly sensitive olfactory biosensors for the detection of volatile organic compounds by surface plasmon resonance imaging

International audience; Nowadays, monitoring of volatile organic compounds (VOCs) is very important in various domains. In this work, we aimed to develop sensitive olfactory biosensors using odorant binding proteins (OBPs) as sensing materials. Three rat OBP3 derivatives with customized binding properties were designed and immobilized on the same chip for the detection of VOCs in solution by surface plasmon resonance imaging (SPRi). We demonstrated that the proteins kept their binding properties after the immobilization under optimized conditions. The obtained olfactory biosensors exhibited very low limits of detection in both concentration (200pM of beta-ionone) and in molecular weight of …

La perception de la saveur

Novel scaffold of natural compound eliciting sweet taste revealed by machine learning

Abstract Sugar replacement is still an active issue in the food industry. The use of structure-taste relationships remains one of the most rational strategy to expand the chemical space associated to sweet taste. A new machine learning model has been setup based on an update of the SweetenersDB and on open-source molecular features. It has been implemented on a freely accessible webserver. Cellular functional assays show that the sweet taste receptor is activated in vitro by a new scaffold of natural compounds identified by the in silico protocol. The newly identified sweetener belongs to the lignan chemical family and opens a new chemical space to explore.

[Fri-P2-105] Deciphering the ligand binding properties of the mouse odorant-binding protein OBP5 from Mus musculus

International audience; Odorant-binding proteins (OBPs) are abundant soluble proteins secreted in the nasal mucus of a variety of species which are believed to be involved in the transport of odorants towards olfactory receptors. In this study, we report the functional characterization of mouse OBP5 (mOBP5). mOBP5 was recombinantly expressed as a hexahistidine-tagged protein in bacteria and purified by metal affinity. Oligomeric state and secondary structure composition of mOBP5 was investigated using gel filtration and circular dichroism spectroscopy. Fluorescent experiments revealed that mOBP5 interacts with the fluorescent probe N-phenyl naphthylamine (NPN) with a micromolar affinity. Co…

Production of sweet-tasting proteins in yeast: achievements and perspectives

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

International audience

Volatile and odour-active compounds of air-classified faba bean fractions

Perception périphérique des signaux sensoriels. 1- Gustation

National audience

Saveur amère : de la molécule au comportement

La saveur amère permet aux mammifères d’éviter l’ingestion d’aliments poten-tiellement contaminés par des substances amères toxiques fréquemment retrouvées dans notre environnement. La détection de ces molécules aux structures chimiques diverses est réalisée par une famille de récepteurs appelés TAS2R. L’être humain est pourvu de 25 TAS2R aux spectres de reconnaissance plus ou moins larges pour détecter un grand nombre de molécules amères. Des tests fonctionnels in vitro ont été développés afin de détermi-ner le profil d’activation des TAS2R humains. De nombreuses molécules, d’origines natu-relles ou synthétiques ont pu être identifiées comme capable d’activer ces TAS2R. Ces tests fonctionn…

Strategy for recombinant expression of functional N-terminal domain of human T1R3 taste receptor produced in Escherichia Coli

International audience

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

International audience

3D-QSAR study of ligands for a human olfactory receptor

Abstract Only about 350 olfactory receptors (OR) provide a basis for the remarkable ability of humans to recognise and discriminate a large number of odorants. A recent study reports the odorant repertoire of a human class II OR called OR1G1, including both agonists and antagonists. We used these affinity data to perform a 3D molecular modelling study of these ligands using Catalyst/HypoGen software (Catalyst v4.9.1, Accelrys Inc., San Diego, 2004) to propose alignment models for OR1G1 ligands. We obtained a triple-alignment model, which satisfactorily explained the experimental activities and was able both to predict the antagonist effects of some compounds and to identify new potent agoni…

Physiologie de la perception du goût sucré

Plant polyphenols, chemoreception, taste receptors and taste management

International audience; Purpose of review Polyphenols display beneficial health effects through chemopreventive actions on numerous chronic diseases including cancers, metabolic disorders, reproductive disorders and eating behaviour disorders. According to the principle of chemoreception, polyphenols bind cellular targets capable of accepting their stereochemistry, namely metabolizing enzymes and protein receptors, including taste receptors. The extraoral expression of taste receptors and their pharmacological interest in terms of novel drug therapies open up new perspectives on the potential use of these compounds and their interactions with other chemicals in cells. These new perspectives…

Sweeteners and sweetness enhancers

indexation en cours; PURPOSE OF REVIEW: The current review summarizes and discusses current knowledge on sweeteners and sweetness enhancers. RECENT FINDINGS: The perception of sweet taste is mediated by the type 1 taste receptor 2 (T1R2)/type 1 taste receptor 3 (T1R3) receptor, which is expressed in the oral cavity, where it provides input on the caloric and macronutrient contents of ingested food. This receptor recognizes all the compounds (natural or artificial) perceived as sweet by people. Sweeteners are highly chemically diverse including natural sugars, sugar alcohols, natural and synthetic sweeteners, and sweet-tasting proteins. This single receptor is also the target for developing …

The Recent Development of a Sweet-Tasting Brazzein and its Potential Industrial Applications

International audience; Brazzein is a small heat- and pH-stable sweet-tasting protein isolated from the West African plant, Pentadiplandra brazzeana. Brazzein combines a highly sweet potency, a long history of human consumption, and a remarkable stability, giving it great potential as a natural sweetener. Due to the difficulties of obtaining brazzein from its natural source, several efforts have been made to express brazzein using various heterologous expression systems. This chapter describes the biochemical, structural, sensory, and physiological properties of brazzein. We will summarize the current knowledge of the structure-activity relationship of brazzein. The biotechnological product…

Des récepteurs gustatifs aux nouvelles approches biotechnologiques pour améliorer le goût des protéines

Physiology of taste and olfaction

Tracking ligand-binding effect on protein stability by CD spectroscopy

The influence of protein-ligand interactions on protein stability is usually assessed by measurements in the liquid phase. CD spectroscopy appears to be a tool of choice to i) measure the conformation of the protein in different phases and to ii) follow the conformational changes of the protein upon binding.We therefore studied the stability of the rat odorant binding protein 3 (OBP3), its ability to remain functional and a preliminary test of its ligand binding specificity in the dry state. Solid-state spectra were performed on dry thin films prepared by drop casting of initial buffered aqueous solutions of the rat OBP3 onto optically transparent CaF2 windows and subsequently dried under l…

Taste perception and integration

Revue; IntroductionThe sense of taste is essential for the evaluation of food quality. It allows, at the level of the oral cavity, to evaluate the caloric content of the consumed food, to detect the presence of salt, and protect us against the ingestion of toxic molecules. Our gustatory system allows the perception of different food constituents as alkali metallic salts (salty), acids (sour), sugars (sweet), and bitter compounds. Umami is a different taste, arising from the perception of amino acids, such as l-glutamate, and 5′-ribonucleotides. Other taste qualities are still a matter of debate, including fat taste, corresponding to the taste of fatty acids (Khan and Besnard, 2009), metalli…

Optimisation de la gestion des bruches et de la transformation des féveroles et lentilles pour de nouveaux produits agroalimentaires contenant des protéines végétales

International audience

Rôles fonctionnels des récepteurs gustatifs au sucré

Rôles fonctionnels des récepteurs gustatifs au sucré. 9. école de la SFN : Sensing glucido-lipidique & comportement alimentaire

Perception des protéines sucrées

"Comprendre la vie"

Ma thèse en 180 secondes : la victoire de Karen Rihani

The role of Odorant-Binding Proteins in nutrition under the control of microbiota

Chemosensory signalling pathways involved in sensing of amino acids by the ghrelin cell

AbstractTaste receptors on enteroendocrine cells sense nutrients and transmit signals that control gut hormone release. This study aimed to investigate the amino acid (AA) sensing mechanisms of the ghrelin cell in a gastric ghrelinoma cell line, tissue segments and mice. Peptone and specific classes of amino acids stimulate ghrelin secretion in the ghrelinoma cell line. Sensing of L-Phe occurs via the CaSR, monosodium glutamate via the TAS1R1-TAS1R3 while L-Ala and peptone act via 2 different amino acid taste receptors: CaSR & TAS1R1-TAS1R3 and CaSR & GPRC6A, respectively. The stimulatory effect of peptone on ghrelin release was mimicked ex vivo in gastric but not in jejunal tissue …

Functional roles of the sweet taste receptor in oral and extraoral tissues

International audience; Purpose of review: This review summarizes and discusses the current knowledge about the physiological roles of the sweet taste receptor in oral and extraoral tissues. Recent findings: The expression of a functional sweet taste receptor has been reported in numerous extragustatory tissues, including the gut, pancreas, bladder, brain and, more recently, bone and adipose tissues. In the gut, this receptor has been suggested to be involved in luminal glucose sensing, the release of some satiety hormones, the expression of glucose transporters, and the maintenance of glucose homeostasis. More recently, the sweet taste receptor was proposed to regulate adipogenesis and bon…

Les animaux ont-il un "sens du goût" ?

Structure of rat odorant-binding protein OBP1 at 1.6 angstrom resolution

The nasal mucosa is a specialist interfacial region sandwiched between the olfactory system and the gaseous chemical milieu. In mammals and insects, this region is rich in odorant-binding proteins that are thought to aid olfaction by assisting mass transfer of the many different organoleptic compounds that make up the olfactory landscape. However, in mammals at least, our grasp on the exact function of odorant-binding proteins is tentative and better insight into the role of these proteins is warranted, not least because of their apparent significance in the olfactory systems of insects. Here, the crystal structure of rat odorant-binding protein 1 is reported at 1.6 Å resolution. This prote…

Structure-based virtual screening of bitter taste receptors

Understanding how chemicals code for a certain type of taste is fundamental for the development of a rational method to create new taste modulators. The identification of these new candidates is important for the food industry and would also be beneficial for the pharmacology industry. In humans, the bitter taste depends on a large family of 25 taste receptors type 2 (TAS2Rs) belonging to the G protein-coupled receptor (GPCR) family. They are classified distantly related to class A GPCR and, to date, the experimental structures have not been determined for any TAS2Rs. Here we present a new structure-based virtual screening strategy to expand the chemical space of bitter taste receptors. Com…

Taste perception: from molecule to eating behaviour

The sense of taste has a role in human nutrition, it help to orient our food choices and avoid the ingestion of toxi compounds. Advances in molecular biology, cell biology an, biochemistry were used to identify and characterize the main taste receptors. The identification of these receptors allow a better understanding of the physiological processes tha govern taste perception. The presence of genetic polymorphisr in these receptors explains interindividual differences in tast perception.

C-terminal amino acids are essential for human heat shock protein 70 dimerization

The human inducible heat shock protein 70 (hHsp70), which is involved in several major pathologies, including neurodegenerative disorders and cancer, is a key molecular chaperone and contributes to the proper protein folding and maintenance of a large number of protein structures. Despite its role in disease, the current structural knowledge of hHsp70 is almost exclusively based on its Escherichia coli homolog, DnaK, even though these two proteins only share ~50 % amino acid identity. For the first time, we describe a complete heterologous production and purification strategy that allowed us to obtain a large amount of soluble, full-length, and non-tagged hHsp70. The protein displayed both …

Recombinant expression of the N-terminal domain of human T1R2 taste receptor: interaction with brazzein, a sweet-tasting protein

Diluer le whisky améliore-t-il vraiment son goût ?

Diluer l'alcool pour mieux le déguster ? Contre-intuitif... Pourtant, les connaisseurs le savent : dans le whisky, un peu d'eau révèle toutes les saveurs.

Can aroma compounds really improve the taste of sugar-reduced foods

International audience

A new odorant-binding protein XlaeOBP identified in the aerial olfactory system of Xenopus laevis and Xenopus tropicalis

National audience

Des récepteurs à l'odeur : l'olfaction au quotidien

Une des particularités du système olfactif est sa capacité à détecter et discriminer une myriade de composés odorants, le plus souvent présents en mélanges à des concentrations très faibles. Cette détection chimique est fondée sur une reconnaissance stéréochimique d'un ensemble complexe de molécules très diverses par des récepteurs olfactifs (RO). Des études génétiques conduites chez les rongeurs dès le début des années 1990 ont permis de dénombrer et d’identifier les gènes codant les récepteurs olfactifs. Cette découverte majeure a valu à Linda Buck et Richard Axel d’obtenir le Prix Nobel de médecine et physiologie en 2004. Des études génétiques ont révélé ensuite chez l’être humain la pré…

Document de synthèse du groupe de travail "enjeux et questions de recherche sur protéines végétales communes entre les départements TRANSFORM & BAP"

National audience

Bioinspired sensors from olfactory proteins

Les molécules odorantes, sapides et trigéminales

National audience

Volatile and odour-active compounds of air-classified faba bean fractions

Faba bean is an interesting alternative to animal proteins due to environmental, food functionality and nutritional benefits. Air-classification is a dry process based on the separation of the coarse fraction (starch fraction) and the fine fraction (protein fraction). Volatile compounds, and especially odour-active ones, contribute to pulse’s off-notes that decrease the consumer acceptability. Degradation of amino acids, carotenoid and free fatty acid oxidations are the origins of these molecules and happen during plant growth, storage and transformation stages. Today, a little is known about volatile and mainly odour-active compounds of faba beans. To better understand the volatiles involv…

Prediction of sweetness potency from sweet taste receptor dose-response curves

International audience

Perceptual responses to odorant mixtures originate mainly from peripheral processing

International audience

Development of novel biomimetic sensor materials for optoelectronic nose applications

International audience

Taste receptors to L-glutamate

National audience

La physiologie du goût revisitée

Interaction between odorants and proteins involved in the perception of smell: the case of odorant-binding proteins probed by molecular modelling and biophysical data

A joint approach that combines molecular modelling and fluorescence spectroscopy is used to study the affinity of an odorant binding protein towards various odorant molecules. We focus on the capability of molecular modelling to rank odorants according to their affinity with this protein, which is involved in the sense of smell. Although ligand-based approaches are unable to propose an accurate model attending to the strength of the bond with the odorant-binding protein, receptor-based structures considering either static or dynamic structure of the protein perform equally to discriminate between good, medium and low affinity odorants. Such approaches will be useful for further rational des…

A self-inducible heterologous protein expression system in Escherichia coli

AbstractEscherichia coli is an important experimental, medical and industrial cell factory for recombinant protein production. The inducible lac promoter is one of the most commonly used promoters for heterologous protein expression in E. coli. Isopropyl-β-D-thiogalactoside (IPTG) is currently the most efficient molecular inducer for regulating this promoter’s transcriptional activity. However, limitations have been observed in large-scale and microplate production, including toxicity, cost and culture monitoring. Here, we report the novel SILEX (Self-InducibLe Expression) system, which is a convenient, cost-effective alternative that does not require cell density monitoring or IPTG inducti…

Système d’expression auto-inductible n° 3.026.109

En cours d'enregistrement international N° et date de dépôt : FR1459019 - 2014-09-24 ; n° et date de publication de la demande : FR3026109 - 2016-03-25 (BOPI 2016-12).

Development of brazzein mutants with sweetness-enhancing properties

International audience

Des Odorant-Binding Proteins pour la conception de nez électronique

La physiologie du goût : des récepteurs à la saveur

Pour en savoir plus : Briand, L. (2016). La physiologie du goût. Textes et Documents pour la Classe (1102), 52-56.; Le sens du goût avec le sens de l’odorat est l’un des sens le plus important impliqué dans la perception des aliments. Le sens du goût est dédié à l’évaluation du contenu nutritif des aliments. La détection des molécules sucrées et des acides aminés (goût umami) permet d’identifier des nutriments riches en énergie. À l’inverse, la perception de l’amertume génère des comportements alimentaires aversifs. Grâce à elle, nous évitons les composés toxiques, tels la strychnine ou d’autres alcaloïdes végétaux. Détecter le goût salé est également de première importance pour maintenir l…

Goût et Olfaction

Le goût du gras et autres saveurs ?

Des saveurs aux récepteurs : une histoire de goût

Journal AFDIAG Infos = Magazine d’informations trimestriel de l'Association qui paraît 4 fois par an.Les publications sont réservées aux adhérents de l’AFDIAG et aux médecins.; De nombreux sens régissent notre comportement alimentaire. Parmi eux, la gustation joue un rôle déterminant pour orienter nos choix culinaires. Le sens du goût nous est familier et pourtant, il constitue un des sens les plus complexes. Depuis une dizaine d’années néanmoins, de notables progrès ont été réalisés dans sa connaissance, depuis la découverte des récepteurs gustatifs jusqu’à l’identification des gènes responsables de nos différences de préférences gustatives.

Numerical models contribute to expand the sweet taste chemical space

Le goût des animaux : enjeu d’appétence en petfood

Les animaux de compagnie partagent-ils le même univers sensoriel que leurs maîtres ? Comprendre leurs préférences gustatives est indispensable au développement de produits petfood. Ce qu’ils aiment, ce qu’ils rejettent, et pourquoi : éclairage avec Loïc Briand, directeur de recherche INRA au CSGA.

Commencing countdown engines on - interplanetary flavour perception on a mission to Mars

International audience

Edito : Bien plus qu'une expérience sensorielle !

Le goût est un système de détection chimique capable d’évaluer le contenu nutritif des aliments et de signaler la présence de molécules toxiques. Ce sens nous est familier et pourtant, il est l’un des plus complexes. La connaissance des mécanismes physiologiques de la perception gustative a fortement progressé au cours de la dernière décennie. De nouvelles saveurs ont, en outre, été proposées telles que la saveur umami ou le goût du « gras », et les principaux récepteurs impliqués dans la gustation ont été identifiés. Des analyses de génomes ont, quant à elles, révélé que des différences génétiques pouvaient modifier notre perception des saveurs et expliquer nos comportements alimentaires. …

Extracellular loop 2 of G protein-coupled olfactory receptors is critical for odorant recognition

International audience; G protein-coupled olfactory receptors (ORs) enable us to detect innumerous odorants. They are also ectopically expressed in non-olfactory tissues and emerging as attractive drug targets. ORs can be promiscuous or highly specific, which is part of a larger mechanism for odor discrimination. Here, we demonstrate that the OR extracellular loop 2 (ECL2) plays critical roles in OR promiscuity and specificity. Using site-directed mutagenesis and molecular modeling, we constructed 3D OR models in which ECL2 forms a lid over the orthosteric pocket. We demonstrate using molecular dynamics simulations that ECL2 controls the shape and the volume of the odorant-binding pocket, m…

Plasmalogen depletion in Müller glia alters both Cx43 expression and gap junction intercellular communication with neighbouring astrocytes

International audience

3D-QSAR study of ligands for two human olfactory receptors

National audience

Les récepteurs olfactifs et le codage des odeurs

The first step of the olfactory detection involves the activation by odorants of olfactory receptors, which are membrane proteins embedded in the membrane of olfactory neurons. Odour coding results from the combinatory activation of a set of receptors and rests on their clonal expression. Neuronal olfactory connexion leads to the formation, in the cortex, of a specific sensory map, which gives rise to the odor perception. This combinatorial system allows, with approximately 340 different receptors, to discriminate myriads of odorants that are natural or not (new cooking flavours, synthetic chemicals…). The extreme olfactory genome diversity in human beings may explain different food behavio…

Le goût, une affaire de nez ? 80 clés pour comprendre le goût

Savez-vous que nous goûtons avec le nez ? Le goût nous est familier et pourtant, il constitue l’un des sens les plus complexes. Les scientifiques ont découvert les récepteurs qui permettent à nos papilles de percevoir les différentes saveurs.Savez-vous que nous avons un seul type de récepteur à la saveur sucrée alors que nous possédons 25 récepteurs à l’amertume ? Pourquoi avons-nous tous des goûts différents ? Pourquoi le goût peut-il évoluer au cours de la vie ? L’identification des gènes du goût a permis de comparer l’équipement en récepteurs gustatifs de nombreuses espèces animales. Savez-vous que le chat ne perçoit pas le goût sucré et que le dauphin est insensible à l’amertume ? Des r…

'Quel menu en 2049 ?' : ce que nous mangerons demain... et comment nous le produirons. Dans Newsletter du Centre INRA de Bourgogne-Franche-Comté n° 10 du 19 juin 2019

Jeudi 13 juin, dans la salle des États du Palais des Ducs de Dijon, on a parlé agroécologie, alimentation durable et gastronomie à l’occasion d’une soirée-conférence consacrée à notre assiette… dans 30 ans ! Parmi les experts conviés par l’hebdomadaire L’Obs, le Centre Inra Bourgogne-Franche-Comté a apporté sa contribution au débat. (...)

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

Investigation of a new chemosensory method using three taste inhibitors to study the taste perception mechanism in domestic cats: examples of bitter, umami and kokumi tastes

Investigation of a new chemosensory method using three taste inhibitors to study the taste perception mechanism in domestic cats: examples of bitter, umami and kokumi tastes. 39. annual meeting - association for chemoreception sciences (AChemS)

Oral and extra-oral receptors: what roles?

La perception du goût est médiée par différents types de récepteurs impliqués dans la perception de chacune des cinq saveurs fondamentales à savoir le salé, le sucré, l’acide, l’amer et l’umami (perception de certains acides aminés tels que le L-glutamate). L’identification de ces différents récepteurs a notamment permis de mieux comprendre les mécanismes moléculaires sous-jacents à ces perceptions. Le nombre de récepteurs pour chacune des saveurs ainsi que l’affinité qu’ils présentent pour les molécules sapides sont directement corrélées à la fonction biologique qui sous-tendent la détection de ces molécules. Ainsi, par exemple les sucres naturels source d’énergie pour l’organisme sont dét…

Overexpression of recombinant gurmarin secreted by the yeast Pichia pastoris

International audience

Implication des enzymes dans la perception chimio-sensorielle : une piste dans les troubles olfacto-gustatifs induits par des xénobiotiques ?

International audience

Périréception et protéines porteuses

ISBN-10 : 978-2-7592-1770-0 ; issn : 1777-4624

La brazzéine, une protéine au goût sucré et aux propriétés hors normes

Danss une démarche globale de réduction des sucres dans les produits alimentaires, les protéines au goût sucré sont une alternative encore peu répandue mais à fort potentiel. La brazéine, notamment, possède des propriétés très intéressantes pour l'industrie agroalimentaire. Quelles sont ces propriétés ? Comment peut-on la produire à échelle industrielle ? Quels sont les avantages et les inconvénients de cette protéine ?

Récepteur du goût sucré et diabète

Récepteur du goût sucré et diabète. 6. journée de l'innovation en diabétologie

Perception de la faveur : des récepteurs à l'intégration cérébrale

National audience

Electrochemical detection of the 2-isobutyl-3-methoxypyrazine model odorant based on odorant-binding proteins: The proof of concept

Abstract We developed an electrochemical assay for the detection of odorant molecules based on a rat odorant-binding protein (rOBP3). We demonstrated that rOBP3 cavity binds 2-methyl-1,4-naphtoquinone (MNQ), an electrochemical probe, as depicted from the decrease of its electrochemical signal, and deduced the dissociation constant, Kd MNQ  = 0.5(± 0.2) μM. The amount of MNQ displaced from rOBP3 by 2-isobutyl-3-methoxypyrazine (IBMP), a model odorant molecule, was measured using square-wave voltammetry. The release of MNQ by competition led to an increase of the electrochemical response. In addition, this method allowed determination of the dissociation constant of rOBP3 for IBMP, Kd IBMP  =…

Biochimie des récepteurs du goût sucré

Expression and biophysical characterization of the human T1R1 taste receptor subunit

Expression and biophysical characterization of the human T1R1 taste receptor subunit. 21. Congress of the european chemoreception research organisation (ECRO)

Sur France Inter, Loïc Briand (CSGA) dit tout sur le goût

Que nous dit le goût ? Quelles informations ce sens nous donne-t-il sur les éléments nutritifs que contiennent les aliments, ou sur la présence de molécules toxiques ?Pour répondre à ces questions (et à bien d’autres), Loïc Briand, responsable de l’équipe « Perception de la flaveur : événements péri-récepteurs et interactions perceptives » a participé le 18 décembre dernier à l’émission « Les Savanturiers », présentée par Fabienne Chauvière sur France Inter.

An olfactory receptor detects waxy, fatty and rose odors

An olfactory receptor detects waxy, fatty and rose odors. Salon Européen de la Recherche et de l’Innovation

MIRACULINE as a natural sweetener; the N3S QUALIMENT National project

International audience

Odorant-binding protein-based optoelectronic tongue and nose for sensing volatile organic compounds

International audience; We developed an array of odorant-binding protein mutants with various binding properties. The same design is suitable for the detection and identification of volatile organic compounds (VOCs) both in the liquid phase and in the gas phase by surface plasmon resonance imaging. The obtained optoelectronic tongue is highly selective at low concentrations of VOCs with a low detection limit, but a narrow linear range. In comparison, the optoelectronic nose gives a much higher signal to noise ratio, but the discrimination of VOCs from different chemical classes requires kinetic data to get rid of non-specific signals. This work shows that these optoelectronic tongue and nos…

Enthalpy/entropy compensation effects from cavity desolvation underpin broad ligand binding selectivity for rat odorant binding protein 3

Evolution has produced proteins with exquisite ligand binding specificity, and manipulating this effect has been the basis for much of modern rational drug design. However, there are general classes of proteins with broader ligand selectivity linked to function, the origin of which is poorly understood. The odorant binding proteins (OBPs) sequester volatile molecules for transportation to the olfactory receptors. Rat OBP3, which we characterize by X-ray crystallography and NMR, binds a homologous series of aliphatic gamma-lactones within its aromatic-rich hydrophobic pocket with remarkably little variation in affinity but extensive enthalpy/entropy compensation effects. We show that the bin…

Le point sur... Perspectives thérapeutiques des inhibiteurs du goût sucré

Nous percevons le goût sucré à l’aide d’un récepteur unique, appelé T1R2/T1R3. Ce récepteur nous permet de détecter tous les divers composés chimiques que nous percevons comme sucrés. De façon surprenante, des études récentes ont montré qu’il était présent dans de nombreux tissus et organes en dehors de la cavité orale. Parce qu’il joue un rôle dans le contrôle métabolique, ce récepteur représente une cible potentielle et prometteuse pour le traitement de l’obésité et des maladies métaboliques, telles que le diabète et l’obésité via notamment l’utilisation d’inhibiteurs spécifiques.

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

International audience

Le « goût végétal » : quels enjeux ? - Entretien avec Loïc Briand de l'INRAE

Note verte, odeur d’herbe coupée, amertume ou astringence : les protéines végétales ont des spécificités qui peuvent réduire le plaisir gustatif et freiner leur utilisation. La recherche contemporaine travaille à identifier tous les mécanismes qui sous-tendent la perception sensorielle de ces aliments pour développer des stratégies de compensation.

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…

The bitter taste of vitamins is mediated by human TAS2R activation

Vitamins play an important role in maintaining normal physiologic and metabolic functions. Vitamins are known to generate bitterness, which may contribute to the off-taste of nutritional supplements. This negative sensation may decrease product acceptability and patient compliance. Few studies have examined taste thresholds and sensory sensing mechanisms at the origin of vitamin taste detection. To better understand vitamin bitterness perception, we combined human sensory analysis and taste receptor functional assays. We measured the aqueous taste detection threshold of four B vitamins using sensory difference tests. Challenging the 25 human bitter taste 2 receptors (TAS2Rs), we found that …

Sucralose and Cardiometabolic Health: Current Understanding from Receptors to Clinical Investigations

International audience; The excess consumption of added sugar is consistently found to be associated with weight gain, and a higher risk of type 2 diabetes mellitus, coronary heart disease, and stroke. In an effort to reduce the risk of cardiometabolic disease, sugar is frequently replaced by low- and null-calorie sweeteners (LCSs). Alarmingly, though, emerging evidence indicates that the consumption of LCSs is associated with an increase in cardiovascular mortality risk that is amplified in those who are overweight or obese. Sucralose, a null-caloric high-intensity sweetener, is the most commonly used LCS worldwide, which is regularly consumed by healthy individuals and patients with metab…

Goût sucré et édulcorants : mythes et certitudes

Le sens du goût avec le sens de l’odorat est l’un des sens le plus important impliqué dans la perception des aliments. Le sens du goût est dédié à l’évaluation du contenu nutritif des aliments. La détection des molécules sucrées et des acides aminés permet d’identifier des nutriments riches en énergie. À l’inverse, la perception de l’amertume génère des comportements alimentaires aversifs. Grâce à elle, nous évitons les composés toxiques, tels la strychnine ou d’autres alcaloïdes végétaux. Détecter le goût salé est également de première importance pour maintenir l’homéostasie hydrominérale. Il est en effet capital de trouver du sodium dans l’environnement car nos organismes en perdent const…

Two sexually dimorphic Odorant binding proteins are affected by microbiota

Le masquage de goût : approche scientifique (mécanismes et challenges des industriels)

Une sixième saveur ?

Caractéristique des féculents, une sixième saveur pourrait être bientôt ajoutée à la courte liste des cinq goûts reconnus officiellement à ce jour. Combien de saveurs différentes font-elles la richesse de notre palette gustative ? Cinq, répondent les scientifiques : acide comme le citron, amer comme le café, sucré comme le gâteau, salé comme la chips. Mais aussi – moins connue du grand public – la saveur dite umami, du japonais « délicieux, savoureux », propre au glutamate présent, par exemple, dans la tomate mûre ou le fromage. L’existence de ce cinquième goût est admise par la communauté scientifique depuis 20 ans. Une étude parue dans Chemical Science en date du 23 août 2016 révèle qu’un…

Du goût des protéines végétales au comportement des consommateurs : quelles méthodes d'étude pour quels enjeux ?

National audience

Molécules aromatisantes et sapides

National audience

Expression and characterization of the human sweet taste receptor expressed in a mammalian inducible cell line

International audience; Sweet taste perception is mediated by a heterodimeric receptor composed of the two distinct protein subunits, TAS1R2 and TAS1R3. TAS1R2 and TAS1R3 subunits are members of the small family of class C GPCRs. Class C GPCRs share a large N-terminal domain (NTD) linked to the heptahelical transmembrane domain by a cysteine-rich region. TAS1R2/TAS1R3 is the primary receptor for a diverse range of sweet compounds including natural sugars, sweet amino acids, artificial sweeteners and plant sweet-tasting proteins. In order to understand the molecular mechanisms that govern receptor – ligand interactions and the relative contribution of the two subunits to the detection of swe…

Interactions at the olfactory receptor level contribute to the coding of odorant mixtures

International audience

Nanofitins targeting heat shock protein 110: an innovative immunotherapeutic modality in cancer.

The presence of an inactivating heat shock protein 110 (HSP110) mutation in colorectal cancers has been correlated with an excellent prognosis and with the ability of HSP110 to favor the formation of tolerogenic (M2-like) macrophages. These clinical and experimental results suggest a potentially powerful new strategy against colorectal cancer: the inhibition of HSP110. In this work, as an alternative to neutralizing antibodies, Nanofitins (scaffold ~7 kDa proteins) targeting HSP110 were isolated from the screening of a synthetic Nanofitin library, and their capacity to bind (immunoprecipitation, biolayer interferometry) and to inhibit HSP110 was analyzed in vitro and in vivo. Three Nanofiti…

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

Meeting Abstract; International audience

Flavor receptors

National audience

Biophysical and functional characterization of the human olfactory receptor OR1A1 expressed in a mammalian inducible cell line

International audience; Olfactory receptors (ORs) play a crucial role in detecting the odorant molecules present in the surrounding environment. These receptors, which belong to class A G-protein-coupled receptors, constitute the largest transmembrane protein family in the human genome. Functional studies showed that the OR family includes members that are able to respond to a large set of odorants and members that are activated by a relatively small number of related odorants. To understand the molecular mechanisms that govern the receptor-ligand interactions, we overexpressed the human OR hOR1A1 in a stable tetracycline-inducible HEK293S cell line. This receptor was engineered by insertin…

L'empreinte olfactive

International audience; Une des particularités du système olfactif des vertébrés ou des insectes est sa capacité à détecter et discriminer une myriade de composés odorants, le plus souvent présents en mélanges à des concentrations très faibles. Cette détection chimique est fondée sur une reconnaissance stéréochimique d'un ensemble complexe de molécules très diverses par des récepteurs olfactifs. Des études génétiques conduites chez les rongeurs dès le début des années 1990 ont permis de dénombrer et d’identifier les gènes codant les récepteurs olfactifs. Cette découverte majeure a valu à Linda Buck et Richard Axel d’obtenir le Prix Nobel de médecine et physiologie en 2004. Des études généti…

Taste Perception of Nutrients Found in Nutritional Supplements: A Review

open access review pii: nu11092050.; International audience; Nutritional supplements are prescribed when one's nutritional status is not conducive to good health. These foodstuffs constitute concentrated sources of nutrients such as vitamins, minerals, amino acids, and fatty acids. For nutritional supplements to be effective, patients must consume the amount that has been prescribed for the recommended period of time. Therefore, special attention must be given to the sensory attributes of these products. Indeed, the presence of active compounds can cause an off-taste or aftertaste. These negative sensations can lead to a reduction in the consumption of nutritional supplements and reduce the…

Arômes et saveurs

Parution d'un petit compte-rendu sur le site web de l'académie suite à la communication orale de L. Briand; Arômes et saveurs. Variabilité individuelle des récepteurs chimiosensoriels : récepteurs olfactifs et gustatifs. Séances de l'académie de l'agriculture de France

Biomolecular and cellular approaches to study taste receptors

The 40-Year Mystery of Insect Odorant-Binding Proteins

International audience; The survival of insects depends on their ability to detect molecules present in their environment. Odorant-binding proteins (OBPs) form a family of proteins involved in chemoreception. While OBPs were initially found in olfactory appendages, recently these proteins were discovered in other chemosensory and non-chemosensory organs. OBPs can bind, solubilize and transport hydrophobic stimuli to chemoreceptors across the aqueous sensilla lymph. In addition to this broadly accepted “transporter role”, OBPs can also buffer sudden changes in odorant levels and are involved in hygro-reception. The physiological roles of OBPs expressed in other body tissues, such as mouthpar…

Goût: des récepteurs à la saveur

Gustation : sens essentielGustation : généralités(...)

Le goût : du récepteur à la saveur

Moins de sel, plus de goût

To Mars and back - with added flavour!

To Mars and back - with added flavour!. 257. National Meeting of the American-Chemical-Society (ACS)

Sucralose and acesulfame K modulate human and rodent vascular smooth muscle contractility independently of the presence of the sweet taste receptor. A study of the SOSweet project

SILEX : une publication et un brevet pour une équipe du CSGA

C'est un projet mené par Loïc Briand et Fabrice Neiers (équipe de L. Briand), du CSGA. L'équipe a breveté en 2016 une technologie qui permet de transférer la capacité d’induire la production d’une protéine recombinante d’intérêt de manière autonome dans la bactérie Escherichia. coli, sans utilisation d’un milieu de culture particulier. Cette capacité est nommée auto-induction programmée (Self Inductible EXpression system, d’où SILEX.)Les protéines recombinantes représentent une ressource importante car la demande explose dans tous les secteurs industriels : production de médicaments, réalisation de diagnostics médicaux, chimie, agroalimentaire.Afin de produire ces protéines recombinantes, u…

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

International audience

Development of a new in vitro model of oral mucosa to investigate a new hypothesis on the molecular origin of astringency

Astringency is described as an oral tactile perception occurring during the consumption of tannin-rich foods. This sensation, mediated by the trigeminal nerves, participates negatively to the flavor of foods leading to the rejection of food with high astringency by the consumer. The exact molecular mechanism of its origin and the nature of the sensory receptors activated are still under debate. Up to recently, the main hypotheses involved changes in the lubrication properties of the oral cavity triggering the activation of mechanoreceptors. Recently, we have put a new hypothesis involving the mucin MUC1 forward as an explanation of the origin of astringency. MUC1 is a transmembrane mucin wi…

Ces molécules qui éveillent nos papilles

The sense of taste is a chemical sense and one of the most ancestral sensory modalities. It allows detectingand appreciating taste molecules present in our food. Beyond our vital needs, the pleasure elicited from whatwe eat can drive our feeding behaviors sometimes up to excess. Food intake involves several sensorysystems, mainly smell and taste. The underlying molecular mechanisms are relatively complex. This articlefocuses on the extent of the chemical space associated with the five primary tastes (sour, salty, sweet, bitterand umami), and details the fundamental role of gustatory receptors in the perception of taste as well aswithin interindividual variabilities.

Characterization of the ligands for the human umami taste receptor

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…

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…

Novel canine odorant binding proteins

The present invention relates to the use of a sequence chosen among Seq ID No 3, Seq ID No l, Seq ID No 2, Seq ID No 4, Seq ID No 5, Seq ID No 6, Seq ID No 7, Seq ID No 8, and functional variants thereof, as an odorant binding protein (OBP).

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 …

Recombinant expression, in vitro refolding, and biophysical characterization of the N-terminal domain of T1R3 taste receptor

Facteur d'impact (5 ans) : 1,617Notoriété à 2 ans : Acceptable (biochem.res.methods); The sweet taste receptor is a heterodimeric receptor composed of the T1R2 and T1R3 subunits, while T1R1 and T1R3 assemble to form the umami taste receptor. T1R receptors belong to the family of class C G-protein coupled receptors (GPCRs). In addition to a transmembrane heptahelical domain, class C GPCRs have a large extracellular N-terminal domain (NTD), which is the primary ligand-binding site. The T1R2 and T1R1 subunits have been shown to be responsible for ligand binding, via their NTDs. However, little is known about the contribution of T1R3-NTD to receptor functions. To enable biophysical characteriza…

Development of a novel olfactory biosensor based on surface plasmon resonance imaging

Monitoring volatile organic compounds (VOCs) is a key issue in many industrial domains, from food industry to public safety. Here, we propose a biomimetic alternative to traditional analytical methods such as gas chromatography and mass spectroscopy. Novel olfactory biosensor was developed using surface plasmon resonance imaging (SPRi) and odorant binding proteins (OBPs). OBPs are robust and can reversibly bind VOCs with a micromolar affinity. Herein, three mutant OBPs with tuned binding properties were immobilized on a chip in a microarray format to detect VOCs in liquid. We demonstrated that SPRi was efficient for the analysis of VOCs. The olfactory biosensor exhibited a low limit of dete…

Perception du goût : sommes-nous tous égaux ?

National audience; Les sens olfactifs et gustatifs jouent un rôle essentiel dans le comportement alimentaire. L'être humain est capable de percevoir des milliers de composés odorants grâce à un système de codage combinatoire impliquant environ 340 récepteurs olfactifs. Les récepteurs olfactifs sont sujets à un important polymorphisme génétique susceptible d'induire différentes perceptions de certaines odeurs. La perception des molécules sapides implique un nombre beaucoup plus restreint de récepteurs dont certains restent encore à découvrir. Un polymorphisme génétique à l'origine de variations importantes dans les seuils de perception de certains composés sapides affecte également les récep…

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

Nos 5 "super-sens". Bien plus aiguisés qu'on ne le croyait !

Revue; International audience; Limités, nos cinq sens ? Moins affûtés que ceux des animaux ? Détrompez-vous ! nous dit Hugo Leroux. De récents travaux révèlent que nos récepteurs sensoriels sont non seulement incroyablement sensibles, mais capables de véritables prouesses.

Goût et odorat : des chercheurs dijonnais planchent

Activation of a Sweet Taste Receptor by Oleanane-Type Glycosides from Wisteria sinensis

The phytochemical study of Wisteria sinensis (Sims) DC. (Fabaceae), commonly known as the Chinese Wisteria, led to the isolation of seven oleanane-type glycosides from an aqueous-ethanolic extract of the roots. After successive purifications by various chromatographic methods, like solid/liquid chromatographic methods, vacuum liquid chromatography (VLC), medium pressure liquid chromatography (MPLC), on normal and reverse phase (RP-18 silica gel), and size exclusion chromatography on Sephadex L, their structures were elucidated by an extensive 600 MHz NMR analysis including 1D and 2D NMR experiments as well as ESI-MS. Among the seven isolated saponins, two have never been reported before : 3…

An efficient Escherichia coli expression system for the production of a functional N-terminal domain of the T1R3 taste receptor.

http://www.landesbioscience.com/; International audience; Sweet taste is mediated by a dimeric receptor composed of two distinct subunits, T1R2 and T1R3, whereas the T1R1/T1R3 receptor is involved in umami taste perception. The T1R1, T1R2, and T1R3 subunits are members of the small family of class C G protein-coupled receptors (GPCRs). The members of this family are characterized by a large N-terminal domain (NTD), which is structurally similar to bacterial periplasmic-binding proteins and contains the primary ligand-binding site. In a recent study, we described a strategy to produce a functional dimeric human T1R3-NTD. Although the protein was expressed as inclusion bodies (IBs) using the …

Perception des arômes et des odeurs : sommes-nous tous égaux ?

Development of olfactory biosensors for the detection of small molecules by SPRi

National audience

Trace amine associated receptors (TAARs) response to amines are largely affected by sequences variants

The Trace Amine Associated Receptors (TAARs) are a family of chemosensory receptors that recognize volatile amines. These receptors are few in number and highly conserved, compared to regular olfactory receptors. Polymorphisms in the TAAR family can have a drastic impact on our perception of amine compounds. Our study combine numerical simulations with in vitro experiments to reveal the activation mechanisms of the human TAAR5 receptor. The study focused on the hTAAR5-S95P polymorphism, which is found at high frequency in Nordic countries. This mutation affects the perception of trimethylamine (TMA), making individuals less able to perceive the smell of rotten fish caused by this molecule. …

Des approches biotechnologiques au service du goût

National audience

Development of brazzein mutants with sweetness-enhancing

Development of brazzein mutants with sweetness-enhancing. Annual Meeting Innovation Alliance NatLifE 2020

Development of sweet-tasting proteins using the yeast Pichia pastoris

Enzymatic modulation of the bitter taste in Human and Drosophila

Enzymatic modulation of the bitter taste in Human and Drosophila. 4. International Conference on Agricultural and Biological Sciences (ABS 2018)

Stratégie de réduction du sucre

Development of sweet-tasting proteins using the yeast Pichia pastoris - industrial feasibility studies

ARET : colloque 2018 au CSGA Dijon. 28 et 29 mai 2018 - CSGA, 9E boulevard Jeanne d'Arc, Dijon

L'Association pour la REcherche en Toxicologie (ARET) organise un colloque sur le thème "Substances odorantes et sapides : du plaisir des sens aux cibles biologiques", lundi 28 et mardi 29 mai 2018 au CSGA. Ce colloque bénéficie du soutien du département AlimH. Invité d'honneur de la table ronde: Roland Salesse.

Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to bitter molecules in food

International audience

Le goût : comment ça marche ?

Decoding sweet taste from chemical structures

International audience

Specific expression of olfactory binding protein in the aerial olfactory cavity of adult and developing Xenopus

International audience

Functional characterization of the ligand binding domain of the cat T1R1 taste receptor

The umami taste receptor is a heterodimeric G-protein coupled receptor (GPCR), composed of two subunits called T1R1 and T1R3. Both subunits are class C GPCRs whose members share a common architecture composed of a large N-terminal domain (NTD) connected to a heptahelical transmembrane domain by a short cysteine-rich domain. Cellular assays combined with molecular docking and site-directed mutagenesis studies have revealed that the NTD of the T1R1 subunit contains the primary binding site for umami stimuli, such as L-glutamate (L-Glu) for humans. Inosine-5’-monophosphate (IMP) binds close to the opening of the NTD, responsible for the characteristic umami synergy between L-Glu and IMP. Funct…

Santé - Miraculine : la baie qui sucre vos papilles

Présentation du mécanisme d’action de la miraculine qui est une protéine végétale capable de transformer le goût de l’acide en saveur sucrée.

Mechanisms of astringency: Structural alteration of the oral mucosal pellicle by dietary tannins and protective effect of bPRPs

International audience; The interaction of tannins with salivary proteins is involved in astringency. This paper focussed on saliva liningoral mucosae, the mucosal pellicle. Using a cell-based model, the impact of two dietary tannins (EgC and EgCG)on the mucosal pellicle structure and properties was investigated by microscopic techniques. The role of basicProline-Rich-Proteins (bPRPs) in protecting the mucosal pellicle was also evaluated.At low (0.05 mM) tannin concentration, below the sensory detection threshold, the distribution of salivarymucins MUC5B on cells remained unaffected. At 0.5 and 1 mM, MUC5B-tannin aggregates were observed andtheir size increased with tannin concentration and…

Les stratégies payantes pour doper la perception sucrée en bouche

La réduction du sucre s'accélère en 2018. Zoom sur les dernières avancées de la recherche dédiée aux récepteurs gustatifs. Les aromaticiens focalisent leurs recherches sur la mise au point d'arômes modulateurs qui équilibrent le profile aromatique des produits allégés.

Les inhibiteurs du goût sucré : perspectives thérapeutiques

This review summarizes and discusses the current knowledge concerning the physiological role of the sweet taste receptor (T1R2/T1R3) and the potential therapeutic perspectives concerning its inhibition. The functional expression of the sweet taste receptor has also been described in many extra-oral tissues where it has been proposed that the receptor participated in the regulation of metabolic processes. The receptor has been highlighted in various organs such as the intestine, pancreas, bladder, brain, and more recently in the bone and adipose tissue. In the intestine, T1R2/T1R3 receptor has been shown to be involved in the detection of luminal glucose, cytokine release of certain hormones…

Triterpenoid saponins from the cultivar “Green Elf” of Pittosporum tenuifolium

Four oleanane-type glycosides were isolated from a horticultural cultivar “Green Elf” of the endemic Pittosporum tenuifolium (Pittosporaceae) from New Zealand: three acylated barringtogenol C glycosides from the leaves, with two previously undescribed 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, 3-O-β-d-galactopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C, and the known 3-O-β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→3)]-β-d-glucuronopyranosyl-21-O-angeloyl-28-O-acetylbarringtogenol C (Eryngioside L). From the roots, the known 3-O-β-d-glucopyra…

Odorant-binding protein engineering: impact on binding properties

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

International audience

Recent advances in understanding vertebrate odorant-binding proteins

P45 - Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to bitter molecules in food

International audience

Optimized vector for functional expression of the human bitter taste receptor TAS2R14 in HEK293 cells

International audience

Development of innovative blends of sweeteners and sweetness enhancers (S&SE) using sweet taste receptor studies

Expression of functional N-terminal domain of human T1R2 taste receptor

International audience

Structure-function relationships of brazzein, a sweet-tasting protein and its interactions with the human sweet taste receptor

International audience; Brazzein is a small heat- and pH-stable sweet-tasting protein isolated from the West African plant, Pentadiplandra brazzeana. Brazzein combines a highly sweet potency, a long history of human consumption, and a remarkable stability, giving it great potential as a natural sweetener. Due to the difficulties of obtaining brazzein from its natural source, several efforts have been made to express brazzein using various heterologous expression systems. Brazzein like all classes of sweet compounds (natural sugars, natural and artificial sweeteners) are perceived through the activation of the T1R2/T1R3 heterodimeric sweet taste receptor. T1R2 and T1R3 subunits are members o…

Les protéines végétales: dans la tête et dans la bouche du consommateur. Quelles méthodes d’étude pour quels enjeux ?

Expression and characterization of ligand-binding domain of T1R1 taste receptor

International audience; Umami is the typical taste induced by monosodium glutamate,which is thought to be detected by a heterodimeric G-proteincoupled receptors, T1R1 and T1R3. The most unique feature ofumami taste is its potentiation by purine nucleotidemonophosphates (IMP, GMP), which also elicit umami taste bytheir own. Zhang et al. (Proc. Natl Acad. Sci. USA, 2008) haverecently proposed a cooperative ligand-binding model involvingT1R1 N-terminal domain (NTD), where L-glutamate (L-glu)binds close to the hinge region, and purine nucleotides bind to anadjacent site close to the opening of the Venus flytrap domain. Tofurther understand the structural basis of umami stimulirecognition by T1R…

Surface plasmon resonance imaging for sensing volatile organic compounds: Biomimetic olfactory biosensors and optoelectronic nose

National audience; Nowadays, there is a growing demand for the analysis of volatile organic compounds (VOCs) in various domains, including environment, quality control, and medical diagnostics. Traditional analytical methods, though accurate and reliable, require expensive equipment and are often time-consuming and laborious. On the other side, food & fragrance industries employ human sensory panels to evaluate the quality of an odour. However, panellists are expensive to train and employ and they can give biased results. To bridge the gap, we developed different sensor systems inspired by the human nose. Here, a biomimetic olfactory biosensor based on key-and-lock principle was designed us…

Interaction of the n-terminal domain of human t1r2 taste receptor with brazzein, a sweet-tasting protein

Brazzein is a small (6.5 kDa) sweet-tasting protein originating from the fruit of Pentadiplandra brazzeana, a plant found in West Africa. Brazzein like all classes of sweet compounds is perceived through the activation of the T1R2/T1R3 heterodimeric sweet-taste receptor. T1R2 and T1R3 subunits are members of the small family of class C G-protein coupled receptors (GPCRs). Class C GPCRs possess a large N-terminal domain (NTD) linked to seven transmembrane domain by a cysteine rich domain (CRD). The NTD of T1R2 (T1R2-NTD) has been shown to contain the primary binding site for most of the sweet ligands. However, brazzein has been shown to require CRD of human T1R3 for receptor activation [1]. …

Le goût : de la molécule à la saveur

Co-organisation.; Le goût : de la molécule à la saveur. La semaine du Cerveau

MIRACULINE as a natural sweetener; the N3S QUALIMENT project. Potential interest in baking

Miraculine is a glycol-protein extracted from the Miracle fruit which is a berry(Synsepalum dulcificum - Sapotaceae family, Daniell-1952). Common names for the miracle fruit are miracle berry, miraculous berry, sweet berry …. It originated from West Africa and is grown under tropical climate. In the 1970s, it has been attempted to commercialize miraculin on a large scale in the United States under the name of Miralin. The FDA allowed and then blocked the development of this new natural sweetener because no non-toxicity test had been performed. At the same time, aspartame was authorized. Today, miraculin is still not permitted in the USA and in Europe (classified as Novel Food). Besides, it …

Structural and enzymatic characterization of a Drosophila melanogaster glutathione transferase overexpressed in the sensory organs after exposure to bitter molecules in food

Glutathione transferases (GSTs) are ubiquitous key detoxification enzymes that catalyze the conjugation of glutathione to a large variety of xenobiotic chemical including odorants and sapid molecules. A previous study in Drosophila melanogaster demonstrated the existence of a GST specifically expressed in the antenna and involved in signal termination by catalyzing biotransformation of odorant molecules. Genomic analysis allows identifying forty GSTs in Drosophila melanogaster but their biochemistry is poorly documented. Here we demonstrated that among the GSTs, dmelGSTD2-2 was strongly and preferentially overexpressed in the sensory organs (antennae, proboscis, legs, wings) after an exposu…

Characterization of ligands for human T1R3 taste receptor

National audience

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

International audience

Perturbateurs endocriniens : effet sur les préférences gustatives et l'obésité

International audience; Plusieurs études relient l’évolution de l’incidence de l’obésité à une évolution sociétale: l’accès des femmes au travail, les facilités de transport et l’essor de l’industrie agroalimentaire ont généré une "transition nutritionnelle" où le repas mijoté à base de produits frais a fait place au repas vite-prêt et fast-foods. La surconsommation de graisses et sucres et la moindre consommation de fruits et légumes sont bien souvent incriminés. Toutefois, l’usage concomitant de produits chimiques dans la production agricole et la confection de produits raffinés et/ou transformés, pourrait être un facteur aggravant, le taux d’obésité pouvant atteindre 50% en régions pollu…

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

National audience

Relation phénotype-génotype dans le cas de la sensibilité gustative au glutamate

National audience

Factors affecting flavor perception in space: Does the spacecraft environment influence food intake by astronauts?

International audience; The intention to send a crewed mission to Mars involves a huge amount of planning to ensure a safe and successful mission. Providing adequate amounts of food for the crew is a major task, but 20 years of feeding astronauts on the International Space Station (ISS) have resulted in a good knowledge base. A crucial observation from the ISS is that astronauts typically consume only 80% of their daily calorie requirements when in space. This is despite daily exercise regimes that keep energy usage at very similar levels to those found on Earth. This calorie deficit seems to have little effect on astronauts who spend up to 12 months on the ISS, but given that a mission to …

Characterizing the Dynamic Taste and Retro-Nasal Aroma Properties of Oral Nutritional Supplements Using Temporal Dominance of Sensation and Temporal Check-All-That-Apply Methods

International audience; Orally Disintegrating Tablets (ODTs) are used to restore the nutritional status of people suffering from swallowing pathologies such as dysphagia. ODTs are consumed without water intake and are easily swallowed. The main active compounds of ODTs are vitamins and minerals. These nutrients can have a bad taste or aftertaste, which can be masked by sweetening or flavoring. To ensure the effectiveness of masking strategies and to prescribe a product to patients with acceptable sensory qualities, it is essential to perform a precise and complete sensory characterization of these ODTs. Temporal dominance of sensations (TDS) and temporal check-allthat- apply (TCATA) methods…

Olfaction : de la biologie au nez électronique

Olfaction : de la biologie au nez électronique

A biometic olfactory based biosensor combining electrochemistry and odorant-binding

A biometic olfactory based biosensor combining electrochemistry and odorant-binding. Food Factory 2012

Collisional mechanism of ligand release by Bombyx mori JHBP, a member of the TULIP / Takeout family of lipid transporters.

International audience; Juvenile hormones (JHs) regulate important processes in insects, such as postembryonic development and reproduction. In the hemolymph of Lepidoptera, these lipophilic sesquiterpenic hormones are transported from their site of synthesis to target tissues by high affinity carriers, the juvenile hormone binding proteins (JHBPs). Lepidopteran JHBPs belong to a recently uncovered, yet very ancient family of proteins sharing a common lipid fold (TULIP domain) and involved in shuttling various lipid ligands. One important, but poorly understood aspect of JHs action, is the mechanism of hormone transfer to or through the plasma membranes of target cells. Since many membrane-…

Exploring the chemical diversity of essential oils in Armenian markets: a comprehensive analysis of composition profiles

Due to its location at the convergence of multiple biogeographical regions, Armenia experiences significant variations in climate and soil conditions, resulting in a diverse range of plant chemotypes. However, there has been a lack of recent reports on the biological activity of plants found in Armenia's flora. There are few with well-described essential oil profiles, despite the vast biodiversity of Armenian flora. This study aimed to analyse the chemical composition of essential oils used by the population and found in the Armenian market. Unfortunately, only essential oils of foreign origin can be found, like Russia. Three essential oils of Lavandula angustifolia, Abies sibirica, and Ros…

Saviez-vous que le goût est une affaire de nez ? Interview de Loïc Briand dans l'émission de radio C'LeMag

Nos cinq sens et la nature au programme de ce rendez-vous de la rédaction ! Saviez-vous que le goût est une affaire de nez ? C'est le titre de l'ouvrage de Loïc BRIAND. Directeur de Recherche à l'Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), et directeur du Centre des Sciences du Goût et de l’Alimentation de Dijon. Il évoque les recherches menées sur la perte du goût et de l'odorat, liées à la Covid, mais aussi l'ouvrage "Le goût : une affaire de nez ? - 80 clés pour comprendre le goût", paru en octobre dernier chez Quae éditions.

Odorant binding changes the electrical properties of olfactory receptors at the nanoscale

Olfactory receptors (ORs) comprise the largest multigene family in the vertebrates. They belong to the class A (rhodopsin-like) family of G protein-coupled receptors (GPCRs), which are the most abundant membrane proteins, having widespread, significant roles in signal transduction in cells, and therefore, they are a major pharmacological target. Moreover, ORs displayed high selectivity and sensitivity towards odorant detection, a characteristic that raised the interest for developing biohybrid sensors based on ORs for the detection of volatile compounds. The transduction of odorant binding into cellular signaling by ORs is not well understood and knowing its mechanism would enable developin…

Un miracle transformateur de goût : la miraculine, potentiel prometteur pour l'industrie agroalimentaire

Connaissez-vous le fruit miracle ?Non, non, il n’est pas ici question d’un pays magique, ni d’un phénomène cosmique : il s’agit bel et bien d’un nom de fruit existant sur notre planète, aux ressources parfois surprenantes.Ne soyez pas sceptique : une fois informés sur ses étonnantes propriétés, je mets ma main à couper que vous aimeriez en savoir plus, voire même, le goûter.Car le fruit miracle contient une protéine (logiquement appelée « la miraculine ») aux attributs uniques : transformer le goût de l’acide en goût sucré… sans aucun sucre ajouté.Un potentiel prometteur pour des applications industrielles en agroalimentaire. Je vous propose d’en apprendre plus avec Loïc Briand, directeur d…

Towards computational biomimetic nose

International audience

Phenotype genotype relationship in human taste

International audience

Sweet taste receptor-based assay to investigate synergism among sweetener mixtures

Characterization of Drosophila Delta glutathione transferases involved in isothiocyanate detoxification and perception

International audience

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…

COVID 19-Induced Smell and Taste Impairments: Putative Impact on Physiology

This article is part of the Research Topic "The Tribute of Physiology for the Understanding of COVID-19 Disease".; International audience; Smell and taste impairments are recognized as common symptoms in COVID 19 patients even in an asymptomatic phase. Indeed, depending on the country, in up to 85-90% of cases anosmia and dysgeusia are reported. We will review briefly the main mechanisms involved in the physiology of olfaction and taste focusing on receptors and transduction as well as the main neuroanatomical pathways. Then we will examine the current evidences, even if still fragmented and unsystematic, explaining the disturbances and mode of action of the virus at the level of the nasal …

Comment reconnaît-on les saveurs ?

La gastronomie française, reconnue patrimoine immatériel de l’humanité par l’Unesco, fait honneur aux papilles. Mais comment fonctionnent celles-ci ? Explications de Loïc Briand, directeur de recherche au Centre des sciences du goût et de l’alimentation (INRA/Université de Bourgogne).La Croix : Comment reconnait-on une saveur ?Loïc Briand : La saveur suit un trajet de la langue au cerveau. La première étape est la solubilisation de l’aliment par la salive, qui lubrifie et « dépose » les molécules des aliments sur la langue. Ensuite, les récepteurs spécialisés du goût, situés dans les cellules gustatives des papilles, détectent les cinq saveurs : le sucré, l’amertume, l’acidité, le salé et l…

Mucin MUC1: a key protein in oral physiology and the molecular mechanisms of sensory perception of astringency

3D-QSAR study of ligands for two human olfactory receptors

International audience; All living organisms, including human beings, are able to detect and discriminate myriads of structurally diverse odorants through their interaction with olfactory receptors (ORs) (1). It is well accepted that the perception of thousands of odors by about 380 ORs results from a combinatorial coding, in which one OR recognizes multiple odorants and different odorants are recognized by different combinations of ORs (2). In a previous study (3), the functional characterization on two human ORs, called OR1G1 (class II) and OR52D1 (class I) have been performed using 95 odorant molecules. We used these previously obtained functional data (3) to perform a molecular modellin…

Interactions between odorants and glutathione transferases in the human olfactory cleft

AbstractXenobiotic metabolizing enzymes and other proteins, including odorant-binding proteins located in the nasal epithelium and mucus, participate in a series of processes modulating the concentration of odorants in the environment of olfactory receptors (ORs) and finely impact odor perception. These enzymes and transporters are thought to participate in odorant degradation or transport. Odorant biotransformation results in 1) changes in the odorant quantity up to their clearance and the termination of signaling and 2) the formation of new odorant stimuli (metabolites). Enzymes, such as cytochrome P450 and glutathione transferases (GSTs), have been proposed to participate in odorant clea…