Search results for " Taste"
showing 10 items of 104 documents
A self-inducible heterologous protein expression system in Escherichia coli
2016
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…
Predators' consumption of unpalatable prey does not vary as a function of bitter taste perception
2020
Many prey species contain defensive chemicals that are described as tasting bitter. Bitter taste perception is, therefore, assumed to be important when predators are learning about prey defenses. However, it is not known how individuals differ in their response to bitter taste, and how this influences their foraging decisions. We conducted taste perception assays in which wild-caught great tits (Parus major) were given water with increasing concentrations of bitter-tasting chloroquine diphosphate until they showed an aversive response to bitter taste. This response threshold was found to vary considerably among individuals, ranging from chloroquine concentrations of 0.01 mmol/L to 8 mmol/L.…
A cross-talk between fat and bitter taste modalities
2019
International audience; The choice of food is governed largely by the sense of taste. To date, five basic taste modalities have been described; however, there is an increasing agreement on the existence of a 6th fat taste. The taste modalities might interact with each other and also with other senses. The advancements in cellular and molecular biology have helped the characterization of taste signaling mechanisms, down to the receptor level and beyond. CD36 and GPR120 have been shown to be involved in the detection of fat taste while bitter taste is perceived by a number of receptors that belong to a family of taste-type 2 receptors (T2R or TAS2R). Hence, the most common role is played by T…
Plant polyphenols, chemoreception, taste receptors and taste management
2019
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…
Taste of Fat: A Sixth Taste Modality?
2015
International audience; An attraction for palatable foods rich in lipids is shared by rodents and humans. Over the last decade, the mechanisms responsible for this specific eating behavior have been actively studied, and compelling evidence implicates a taste component in the orosensory detection of dietary lipids [i.e., long-chain fatty acids (LCFA)], in addition to textural, olfactory, and postingestive cues. The interactions between LCFA and specific receptors in taste bud cells (TBC) elicit physiological changes that affect both food intake and digestive functions. After a short overview of the gustatory pathway, this review brings together the key findings consistent with the existence…
An increase in visceral fat is associated with a decrease in the taste and olfactory capacity
2017
Introduction Sensory factors may play an important role in the determination of appetite and food choices. Also, some adipokines may alter or predict the perception and pleasantness of specific odors. We aimed to analyze differences in smell–taste capacity between females with different weights and relate them with fat and fat-free mass, visceral fat, and several adipokines. Materials and methods 179 females with different weights (from low weight to morbid obesity) were studied. We analyzed the relation between fat, fat-free mass, visceral fat (indirectly estimated by bioelectrical impedance analysis with visceral fat rating (VFR)), leptin, adiponectin and visfatin. The smell and taste ass…
Sucralose and Cardiometabolic Health: Current Understanding from Receptors to Clinical Investigations
2021
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…
A New Method for Studying Licking Behavior Determinants in Rodents: Application to Diet-Induced Obese Mice
2018
OBJECTIVE An original device for exploring taste-guided reward behavior in rodents using a newly designed computer-controlled liquid delivery system equipped with "lickometers" is described. METHODS This octagonal shaped "gustometer" is composed of eight shutters that give random access during a few seconds to eight bottles delivering different liquid stimuli. This original design, which forces the animal to move for access to the drinking source, allows a simultaneous analysis of the licking behavior and motivation to drink. Determination of the sucrose licking behavior in diet-induced obese mice was used to validate this method because nutritional obesity disturbs the sweet taste percepti…
The Crystal Structure of Gurmarin, a Sweet Taste–Suppressing Protein: Identification of the Amino Acid Residues Essential for Inhibition
2018
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 …
Impact of Very Hot Drink Consumption Habits, Age, and Sex, on Taste Sensitivity
2021
The temperature range for consuming hot drinks includes temperatures that can damage cells on the tongue. We hypothesized that the consumption of very hot drinks can lead to a decrease in the ability to perceive low concentrations of tastants. We evaluated the ability to perceive low concentrations of five prototypical sapid compounds in 42 women and 40 men aged 18–65. A questionnaire made it possible to collect the usual frequencies (number of unit/day) and consumption temperature levels (medium hot/very hot) for four very common hot drinks (coffee, tea, herbal infusions, and hot chocolate). Our results showed that subjects who consumed very hot drinks (versus medium hot) were less sensiti…