The Ability of Basic and Glycosylated Proline-Rich Proteins to Protect Oral Enzymes from Polyphenol Inhibition.

Tannins and flavan-3-ols can exhibit astringency and potential antinutritional effects by binding, aggregating, and precipitating proteins, including digestive and oral enzymes. During oral food processing, these polyphenolic compounds may inhibit enzymes, such as β-glucosidase and glutathione transferase (GSTP1), which help generate taste-active molecules or transform food components for elimination. Saliva contains proline-rich proteins (PRPs) with high affinity for tannins and flavan-3-ols, potentially protecting oral enzymes from inhibition.

Inosine-5'-monophosphate interacts with the TAS1R3 subunit to enhance sweet taste detection.

Umami and sweet taste detection is mediated by the activation of the TAS1R1/TAS1R3 and TAS1R2/TAS1R3 receptors, respectively. TAS1R2-Venus flytrap domain (VFT) constitutes the primary ligand-binding site for most of the sweeteners whereas TAS1R1-VFT contains the orthosteric binding site for umami compounds. Inosine-5'-monophosphate (IMP), previously known to potentiate umami taste, binds to a site of TAS1R1-VFT adjacent to the L-glutamate site leading to umami synergy.

Exploring the role of the MUC1 mucin in human oral lubrication by tribological in vitro studies.

In the context of the oral cavity, an organic layer known as the mucosal pellicle (MP) adheres to the surface of the oral epithelium, playing a pivotal role in lubricating and safeguarding oral tissues. The formation of the MP is driven by interactions between a transmembrane mucin known as MUC1, located on the oral epithelium, and salivary secreted mucin, namely MUC5B and MUC7. This study aimed to investigate the function of MUC1 and the influence of its structure on MP lubrication properties.

Reducing tannic acid astringency with aromas - effectiveness of whisky lactone and isoamyl acetate.

Astringency in foods can significantly affect consumer acceptability. While sugar is known to reduce this sensation, the influence of cross-modal interactions between aroma and astringency remains underexplored. The aim of this study was to evaluate the role of sugar and aroma compounds in modulating the perceived astringency of a tannin solution.

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

Bitter is one of the five basic taste qualities, along with salty, sour, sweet and umami, used by mammals to access the quality of their food and orient their eating behaviour. Bitter taste detection prevents the ingestion of food potentially contaminated by bitter-tasting toxins. Bitter taste perception is mediated by a family of G protein-coupled receptors (GPCRs) called TAS2Rs.

Molecular and Cellular Characterization of the Glutathione Transferases Involved in the Olfactory Metabolism of the Mammary Pheromone.

Odorant metabolizing enzymes, considered as critical olfactory perireceptor actors, control the odor molecules reaching the olfactory epithelium by biotransforming them. As an odorant, the mammary pheromone, i.e.

The vacuolar sulfate transporter PsSULTR4 is a key determinant of seed yield and protein composition in pea.

Pea is a grain legume crop with a high potential to accelerate the food transition due to its high seed protein content and relatively well-balanced amino acid composition. The critical role of external sulfur (S) supply in determining seed yield and seed quality in pea makes it essential to understand the impact of whole plant S management on the trade-off between these two traits. Here, we investigated the physiological relevance of vacuolar sulfate remobilization by targeting PsSULTR4, the only pea sulfate transporter showing substantial similarity to the vacuolar sulfate exporter AtSULTR4;1.

Structural Analysis of the GSTome.

Glutathione transferase (GST) is a superfamily of ubiquitous enzymes, multigenic in numerous organisms and which generally present homodimeric structures. GSTs are involved in numerous biological functions such as chemical detoxification as well as chemoperception in mammals and insects. GSTs catalyze the conjugation of their cofactor, reduced glutathione (GSH), to xenobiotic electrophilic centers.

Structural and Thermodynamic Insights into Dimerization Interfaces of Drosophila Glutathione Transferases.

This study presents a comprehensive analysis of the dimerization interfaces of fly GSTs through sequence alignment. Our investigation revealed GSTE1 as a particularly intriguing target, providing valuable insights into the variations within Delta and Epsilon GST interfaces. The X-ray structure of GSTE1 was determined, unveiling remarkable thermal stability and a distinctive dimerization interface.

Microbial β C-S Lyases: Enzymes with Multifaceted Roles in Flavor Generation.

β C-S lyases (β-CSLs; EC 4.4.1.

Characterization of a Human Respiratory Mucosa Model to Study Odorant Metabolism.

Nasal xenobiotic metabolizing enzymes (XMEs) are important for the sense of smell because they influence odorant availability and quality. Since the major part of the human nasal cavity is lined by a respiratory mucosa, we hypothesized that this tissue contributed to nasal odorant metabolism through XME activity. Thus, we built human respiratory tissue models and characterized the XME profiles using single-cell RNA sequencing.

Evaluating the biomolecular interaction between delamanid/formulations and human serum albumin by fluorescence, CD spectroscopy and SPR: Effects on protein conformation, kinetic and thermodynamic parameters.

Delamanid is an anti-tuberculosis drug used for the treatment of drug-resistant tuberculosis. Since delamanid has a high protein bound potential, even patients with low albumin levels should experience high and rapid delamanid clearance. However, the interaction between delamanid and albumin should be better controlled to optimize drug efficacy.

Glutathione Transferase Omega 1 Localization in Oral Tissues and Interactions with Food Phytochemicals.

Glutathione transferases are xenobiotic-metabolizing enzymes with both glutathione-conjugation and ligandin roles. GSTs are present in chemosensory tissues and fluids of the nasal/oral cavities where they protect tissues from exogenous compounds, including food molecules. In the present study, we explored the presence of the omega-class glutathione transferase (GSTO1) in the rat oral cavity.

Correction: The odorant metabolizing enzyme UGT2A1: Immunolocalization and impact of the modulation of its activity on the olfactory response.

[This corrects the article DOI: 10.1371/journal.pone.

Unlocking Flavor Potential Using Microbial β-Glucosidases in Food Processing.

Aroma is among of the most important criteria that indicate the quality of food and beverage products. Aroma compounds can be found as free molecules or glycosides. Notably, a significant portion of aroma precursors accumulates in numerous food products as nonvolatile and flavorless glycoconjugates, termed glycosidic aroma precursors.

Structure-activity analysis suggests an olfactory function for the unique antennal delta glutathione transferase of Apis mellifera.

Glutathione transferases (GST) are detoxification enzymes that conjugate glutathione to a wide array of molecules. In the honey bee Apis mellifera, AmGSTD1 is the sole member of the delta class of GSTs, with expression in antennae. Here, we structurally and biochemically characterized AmGSTD1 to elucidate its function.

Significant influence of four highly conserved amino-acids in lipochaperon-active sHsps on the structure and functions of the Lo18 protein.

To cope with environmental stresses, bacteria have developed different strategies, including the production of small heat shock proteins (sHSP). All sHSPs are described for their role as molecular chaperones. Some of them, like the Lo18 protein synthesized by Oenococcus oeni, also have the particularity of acting as a lipochaperon to maintain membrane fluidity in its optimal state following cellular stresses.

Perspectives on Nasal Odorant Metabolism Research.

Olfaction is a multi-step process. At a peripheral level, nasal odorant metabolism contributes to olfaction via signal termination, variation, and regulation. We summarize current techniques used to investigate nasal odorant metabolism and give an outlook on future approaches, such as nasal tissue models and their potential contributions in future research directions.

Structural insights into the interactions of glutathione transferases with a nitric oxide carrier and sodium nitroprusside.

Glutathione transferases are detoxification enzymes with multifaceted roles, including a role in the metabolism and scavenging of nitric oxide (NO) compounds in cells. Here, we explored the ability of Trametes versicolor glutathione transferases (GSTs) from the Omega class (TvGSTOs) to bind metal-nitrosyl compounds. TvGSTOs have been studied previously for their ligandin role and are interesting models to study protein‒ligand interactions.

Functional Characterization of the Venus Flytrap Domain of the Human TAS1R2 Sweet Taste Receptor.

The human sweet taste receptor is a heterodimeric receptor composed of two distinct G-protein-coupled receptors (GPCRs), TAS1R2 and TAS1R3. The TAS1R2 and TAS1R3 subunits are members of a small family of class C GPCRs whose members share the same architecture, comprising a Venus Flytrap (VFT) module linked to the seven transmembrane domains (TMDs) by a short cysteine-rich region (CRR). The VFT module of TAS1R2 contains the primary binding site for most of the sweet-tasting compounds, including natural sugars and artificial and natural sweeteners.