Search results for "Proteins."
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Highly sensitive olfactory biosensors for the detection of volatile organic compounds by surface plasmon resonance imaging
2018
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 …
Conservation of the positions of metazoan introns from sponges to humans
2002
Abstract Sponges (phylum Porifera) are the phylogenetic oldest Metazoa still extant. They can be considered as reference animals (Urmetazoa) for the understanding of the evolutionary processes resulting in the creation of Metazoa in general and also for the metazoan gene organization in particular. In the marine sponge Suberites domuncula , genes encoding p38 and JNK kinases contain nine and twelve introns, respectively. Eight introns in both genes share the same positions and the identical phases. One p38 intron slipped for six bases and the JNK gene has three more introns. However, the sequences of the introns are not conserved and the introns in JNK gene are generally much longer. Intron…
Effet colloide-protecteur d'extraits de parois de levures sur la stabilité tartrique d'une solution hydro-alcoolique modèle
1993
<p style="text-align: justify;">L'effet colloïde-protecteur d'extraits mannoprotéiques de parois de levures vis-à-vis de la précipitation tartrique a été étudié en solution hydroalcoolique, en utilisant un IST mètre (Indice de Stabilité Tartrique).</p><p style="text-align: justify;">Nous avons montré que les deux extraits levuriens inhibaient la cristallisation du bitartrate de potassium au même titre que l'acide métatartrique et la carboxyméthylcellulose, mais à un niveau plus faible. Le niveau de stabilité retenu (ISTC-75) est assuré avec des concentrations par litre de 7,5 mg d'acide métatartrique et de 18 mg de carboxyméthylcellulose. Des concentrations en extraits man…
α-Conotoxins EpI and AuIB switch subtype selectivity and activity in native versus recombinant nicotinic acetylcholine receptors
2003
The Xenopus laevis oocyte expression system was used to determine the activities of alpha-conotoxins EpI and the ribbon isomer of AuIB, on defined nicotinic acetylcholine receptors (nAChRs). In contrast to previous findings on intracardiac ganglion neurones, alpha-EpI showed no significant activity on oocyte-expressed alpha3beta4 and alpha3beta2 nAChRs but blocked the alpha7 nAChR with an IC50 value of 30 nM. A similar IC50 value (103 nM) was obtained on the alpha7/5HT3 chimeric receptor stably expressed in mammalian cells. Ribbon AuIB maintained its selectivity on oocyte-expressed alpha3beta4 receptors but unlike in native cells, where it was 10-fold more potent than native alpha-AuIB, had…
Characterization and antimicrobial activity of the volatile components of the flowers of Magydaris tomentosa (Desf.) DC. collected in Sicily and Alge…
2014
The essential oils of the flowers of Magydaris tomentosa (Desf.) DC. (Apiaceae) collected in Sicily (MSi) and Algeria (MAl), respectively, were obtained by hydrodistillation, and their compositions were analysed. The analyses allowed the identification and quantification of 23 components in MSi and 60 compounds in MAl, respectively, showing a very different profile in the composition of the two populations. The main components of MSi were cembrene (28.2%), α-springene (17.5%) and β-springene (14.8%), also present in MAl but in lesser amount (0.4%, 1.8% and 0.9%, respectively), whereas the principal constituents of MAl were (E)-nerolidol (35.4%), α-costol (13.3%) and β-costol (6.8%). Both MS…