by Keyword: Olfactory receptors
Lagunas, Anna, Belloir, Christine, Briand, Loïc, Gorostiza, Pau, Samitier, Josep, (2022). Determination of the nanoscale electrical properties of olfactory receptor hOR1A1 and their dependence on ligand binding: Towards the development of capacitance-operated odorant biosensors Biosensors & Bioelectronics 218, 114755
Garcia-Esparcia, Paula, López-González, Irene, Grau-Rivera, Oriol, García-Garrido, María Francisca, Konetti, Anusha, Llorens, Franc, Zafar, Saima, Carmona, Margarita, del Rio, José Antonio, Zerr, Inga, Gelpi, Ellen, Ferrer, Isidro, (2017). Dementia with Lewy Bodies: Molecular pathology in the frontal cortex in typical and rapidly progressive forms Frontiers in Neurology 8, Article 89
Objectives: The goal of this study was to assess mitochondrial function, energy, and purine metabolism, protein synthesis machinery from the nucleolus to the ribosome, inflammation, and expression of newly identified ectopic olfactory receptors (ORs) and taste receptors (TASRs) in the frontal cortex of typical cases of dementia with Lewy bodies (DLB) and cases with rapid clinical course (rpDLB: 2 years or less) compared with middle-aged non-affected individuals, in order to learn about the biochemical abnormalities underlying Lewy body pathology. Methods: Real-time quantitative PCR, mitochondrial enzymatic assays, and analysis of β-amyloid, tau, and synuclein species were used. Results: The main alterations in DLB and rpDLB, which are more marked in the rapidly progressive forms, include (i) deregulated expression of several mRNAs and proteins of mitochondrial subunits, and reduced activity of complexes I, II, III, and IV of the mitochondrial respiratory chain; (ii) reduced expression of selected molecules involved in energy metabolism and increased expression of enzymes involved in purine metabolism; (iii) abnormal expression of nucleolar proteins, rRNA18S, genes encoding ribosomal proteins, and initiation factors of the transcription at the ribosome; (iv) discrete inflammation; and (v) marked deregulation of brain ORs and TASRs, respectively. Severe mitochondrial dysfunction involving activity of four complexes, minimal inflammatory responses, and dramatic altered expression of ORs and TASRs discriminate DLB from Alzheimer’s disease. Altered solubility and aggregation of α-synuclein, increased β-amyloid bound to membranes, and absence of soluble tau oligomers are common in DLB and rpDLB. Low levels of soluble β-amyloid are found in DLB. However, increased soluble β-amyloid 1–40 and β-amyloid 1–42, and increased TNFα mRNA and protein expression, distinguish rpDLB. Conclusion: Molecular alterations in frontal cortex in DLB involve key biochemical pathways such as mitochondria and energy metabolism, protein synthesis, purine metabolism, among others and are accompanied by discrete innate inflammatory response.
JTD Keywords: Dementia with Lewy bodies, Alzheimer’s disease, α-synuclein, Mitochondria, Protein synthesis, Inflammation, β-amyloid, Olfactory receptors
Sanmartí-Espinal, M., Galve, R., Iavicoli, P., Persuy, M. A., Pajot-Augy, E., Marco, M. P., Samitier, J., (2016). Immunochemical strategy for quantification of G-coupled olfactory receptor proteins on natural nanovesicles Colloids and Surfaces B: Biointerfaces 139, 269-276
Cell membrane proteins are involved in a variety of biochemical pathways and therefore constitute important targets for therapy and development of new drugs. Bioanalytical platforms and binding assays using these membrane protein receptors for drug screening or diagnostic require the construction of well-characterized liposome and lipid bilayer arrays that act as support to prevent protein denaturation during biochip processing. Quantification of the protein receptors in the lipid membrane arrays is a key issue in order to produce reproducible and well-characterized chips. Herein, we report a novel immunochemical analytical approach for the quantification of membrane proteins (i.e., G-protein-coupled receptor, GPCR) in nanovesicles (NVs). The procedure allows direct determination of tagged receptors (i.e., c-myc tag) without any previous protein purification or extraction steps. The immunochemical method is based on a microplate ELISA format and quantifies this tag on proteins embedded in NVs with detectability in the picomolar range, using protein bioconjugates as reference standards. The applicability of the method is demonstrated through the quantification of the c-myc-olfactory receptor (OR, c-myc-OR1740) in the cell membrane NVs. The reported method opens the possibility to develop well-characterized drug-screening platforms based on G-coupled proteins embedded on membranes.
JTD Keywords: Bioelectronic nose, Competitive ELISA, G-protein-coupled receptors quantification, Natural vesicles, Olfactory receptors, Transmembrane proteins
Sanmarti, M., Iavicoli, P., Pajot-Augy, E., Gomila, G., Samitier, J., (2010). Human olfactory receptors immobilization on a mixed self assembled monolayer for the development of a bioelectronic nose Procedia Engineering (EUROSENSOR XXIV CONFERENCE) 24th Eurosensor Conference (ed. Jakoby, B., Vellekoop, M.J.), Elsevier Science (Linz, Austria) 5, 786-789
The present work focuses on the development of an immunosensing surface to build a portable olfactory system for the detection of complex mixture of odorants. Homogeneous cell derived vesicles expressing the olfactory receptors were produced and immobilized with efficiency onto a gold substrate through an optimized surface functionalization method.
JTD Keywords: Bioelectronic noses, Biosensors, Nanoproteoliposomes, Nanosomes, Olfactory receptors, SAMs