Search results for "Hemin"

[P27] Chemo-Biological Analysis Applied to the Olfaction Field

2022

Human are surrounded by numerous odorant molecules in the air from a limited number of olfactory receptors (1), and the odor perceived from these molecules does not comes from the isolated molecules but from their mixture (2). According to the odor perceived from the mixture, we differentiate the heterogeneous perception which is the distinction between the odor components of the mixture and the homogeneous perception that corresponds to the perception of a single odor from the mixture preventing the distinction between odor components of the mixture. There are two types of homogeneous perceptions: the masking and the blending mixture. Masking occurs when one of the mixture components cover…

[P32] Study of Odorants Sharing the Odor Notes of an Aroma Blending Mixture by a Pharmacophore Approach

2022

Odors perceived in our environment are mainly the result of mixtures of odorants whose the specific mechanisms involved in their processing remain poorly understood [1]. In previous studies performed at INRAE-CSGA [2], the perception of a mixture of ethyl isobutyrate (Et-iB, strawberry-like odor, STR) and ethyl maltol (Et-M, caramel-like odor, CAR) was investigated in comparison with a reference (allyl hexanoate, Al-H, pineapple-like odor, PNA) chosen to evoke an odor close to the one expected in the mixture. The binary specific mixture of Et-iB and Et-M was judged as more typical of a pineapple odor than the individual components. Some studies highlight the significance of the biological f…

Numerical models contribute to expand the sweet taste chemical space

2021

Straightforward access to water-soluble unsymmetrical sulfoxanthene dyes: application to the preparation of far-red fluorescent dyes with large stoke…

2014

An efficient synthesis of water-soluble unsymmetrical sulforhodamine/sulforhodol fluorophores containing a single julolidine fragment is presented. Owing to their valuable spectral properties in aqueous buffers, these dyes, especially those bearing a free aniline or phenol moiety, are valuable components of fluorogenic probes for a variety of biosensing applications. A further extension of this synthetic methodology to unusual phenols, namely 7-N,N-dialkylamino-4-hydroxy coumarins has enabled us to provide a new family water-soluble dyes of large Stokes’ shift with far-red spectral features.

Kondrat'eva ligation: Diels-Alder-based irreversible reaction for bioconjugation.

2014

International audience; Diversification of existing chemoselective ligations is required to efficiently access complex and well-defined biomolecular assemblies with unique and valuable properties. The development and bioconjugation applications of a novel Diels-Alder-based irreversible site-specific ligation are reported. The strategy is based on a Kondrat'eva cycloaddition between bioinert and readily functionalizable 5-alkoxyoxazoles and maleimides that readily react together under mild and easily tunable reaction conditions to afford a fully stable pyridine scaffold. The potential of this novel bioconjugation is demonstrated through the preparation of fluorescent conjugates of biomolecul…

Recommandation de parcours de formation dans un contexte mobile

2013

National audience; Les récentes avancées dans les technologies de l'information et de la communication ont vu naître de nouvelles formes d'enseignement. L'apprentissage à distance classique s'enrichit et se transforme pour donner jour à un apprentissage plus flexible, accessible sur de multiples supports, à toute heure et en tout lieu : l'apprentissage mobile. Nos travaux portent sur la conception d'un système de recommandation basé sur le contenu, modélisé en utilisant les technologies du web sémantique. La recommandation prendra en compte l'objectif de formation, mais également les supports disponibles pour dispenser cette formation, les préférences personnelles de l'apprenant, ou encore …

Analyse de sensibilité des modèles de connectivité écologique

2021

Le succès des mesures de conservation de la biodiversité basées sur le maintien de la connectivité écologique dépend de la qualité de la modélisation spatiale des mouvements des espèces. Le calcul de chemins de moindre coût est censé identifier les trajets qui minimisent les coûts de déplacement à travers la matrice paysagère. Il apporte deux types d’information : (i) la localisation spatiale des chemins de moindre coût et (ii) le coût accumulé le long de ces chemins, aussi appelé distance-coût. Cette modélisation spatiale nécessite qu’un coût soit attribué à chaque type d’occupation du sol, constituant alors un scénario de coût. L’influence de ces scénarios sur la localisation des chemins …

Decoding sweet taste from chemical structures

2019

International audience

A Push-Pull Mechanism Helps Design Highly Competent G-Quadruplex-DNA Catalysts

2021

International audience; Massive efforts are currently being invested to improve the performance, versatility, and scope of applications of nucleic acid catalysts. G-quadruplex (G4)/hemin DNAzymes are of particular interest owing to their structural programmability and chemical robustness. However, optimized catalytic efficiency is still bottleneck and the activation mechanism is unclear. Herein, we have designed a series of parallel G4s with different proximal cytosine (dC) derivatives to fine-tune the hemin-binding pocket for G4-DNAzymes. Combining theoretical and experimental methods, we have assessed the dependence of catalytic enhancement on the electronic properties of proximal dCs and…

The noncovalent dimerization of a G-quadruplex/hemin DNAzyme improves its biocatalytic properties.

2020

While many protein enzymes exert their functions through multimerization, which improves both selectivity and activity, this has not yet been demonstrated for other naturally occurring catalysts. Here, we report a multimerization effect applied to catalytic DNAs (or DNAzymes) and demonstrate that the enzymatic efficiency of G-quadruplexes (GQs) in interaction with the hemin cofactor is remarkably enhanced by homodimerization. The resulting non-covalent dimeric GQ–DNAzyme system provides hemin with a structurally defined active site in which both the cofactor (hemin) and the oxidant (H2O2) are activated. This new biocatalytic system efficiently performs peroxidase- and peroxygenase-type biot…