Nicotinic acetylcholine receptors (nAChRs) expressed by dopaminergic (DA) neurons have long been considered as potential therapeutic targets for the treatment of several neuropsychiatric diseases, including nicotine and cocaine addiction or Parkinson's disease. However, DA express mRNAs coding most, if not all, neuronal nAChR subunits, subunit composition functional nAChRs has difficult to establish. Immunoprecipitation experiments performed on mouse striatal extracts allowed us identify...

Glycosaminoglycans are biologically active anionic carbohydrates that among the most challenging biopolymers with regards to their structural analysis and functional assessment. The potential of newly introduced biosensors using protein nanopores have been mainly described for nucleic acids date, has here applied this polysaccharide-based third class bioactive biopolymer. This nanopore approach harnessed in study analyze hyaluronic acid glycosamiglycan its depolymerization-derived...

Sulfs are extracellular sulfatases that have emerged recently as critical regulators of heparan sulfate (HS) activities through their ability to catalyze specific 6-O-desulfation the polysaccharide. Consequently, been involved in many physiological and pathological processes, notably for Sulf-2, development cancers with poor prognosis. Despite growing interest, little is known about structure activity these enzymes way they induce dynamic remodeling HS 6-O-sulfation status. Here, we combined...

This study investigated whether a single administration of range doses (1, 4 and 8 mg kg −1 , i.p.) paroxetine, citalopram or venlafaxine may simultaneously increase extracellular levels 5‐HT ([5‐HT]ext) noradrenaline ([NA]ext) by using in vivo microdialysis the frontal cortex (FCx) awake, freely moving Swiss mice. In paroxetine induced similar increases cortical [5‐HT]ext at three tested, statistically significant [NA]ext . Citalopram increased neither nor lowest dose, but both...

Compared to other analytical methods, matrix‐assisted laser desorption ionization mass spectrometry (MALDI‐MS) presents several unique advantages for the structural characterization of degradation products carbohydrates. Our final goal is implement this technique as a high‐throughput platform, with aim exploring natural bio‐diversity discover new carbohydrate depolymerizing enzymes. In approach, variety carbohydrates will be used enzymes substrates and MALDI‐MS employed monitor...

Signaling cascades rely strongly on protein kinase-mediated substrate phosphorylation. Currently a major challenge in signal transduction research is to obtain high confidence phosphorylation sites and assign them specific kinases. In response bacterial flagellin, pathogen-associated molecular pattern (PAMP), we searched for rapidly phosphorylated proteins Arabidopsis thaliana by combining multistage activation (MSA) electron transfer dissociation (ETD) fragmentation modes, which generate...

Abstract Large‐ring cyclodextrins (CD) are cyclic glucans composed of 9 or more α‐1,4‐linked glucose units. They minor side products bacterial glucanotransferases (CGTases, EC 2.4.1.19) and have previously been available only in very small amounts for studies their properties supramolecular complex formation reactions. We engineered a CGTase to synthesize mainly large‐ring CD facilitating preparation larger amounts. By reversed phase chromatography, we obtained single samples 10 12 units...

The analysis of the microstructure supramolecular copolymers is difficult because their dynamic character. Here, benzene‐1,3,5‐tricarboxamide (BTA) co‐assemblies are analysed by ion mobility ‐ mass spectrometry (IM‐MS) to reveal presence various sequences. For example, IM‐MS mobilogram for hexamers composed 4 units from a first monomer and 2 second broad distribution due 9 possible isomeric sequences, which can be sorted out based on calculated collision cross‐sections. This approach gives...

Abstract Substance P antagonists of the neurokinin-1 receptor type (NK1) are gaining growing interest as new antidepressant therapies. It has been postulated that these drugs exert this putative therapeutic effect without direct interactions with serotonin (5-HT) neurones. Our recent microdialysis experiment performed in NK1 knockout mice suggested evidence changes 5-HT neuronal function (Froger et al. 2001). The aim present study was to evaluate effects coadministration selective reuptake...

Abstract A simple and complete multiresidue method has been developed for the routine determination of 236 pesticides degradation products, in meat based baby‐food. This original approach combines a modified Quick Easy Cheap Effective Rugged Safe (QuEChERS) sample preparation using triple partitioning extraction step with water/ACN/hexane system composed GC programmable temperature vaporization injector hyphenated to an IT‐MS. Detection was performed full scan mode, one quantification ion...

Polysulfated carbohydrates such as heparin (HP) and heparan sulfate (HS) are not easily amenable to usual ultraviolet matrix-assisted laser desorption/ionization-mass spectrometry (UV-MALDI)-MS analysis due the thermal lability of their O- N-SO3 moieties, poor ionization efficiency with common crystalline matrices. Recently, ionic liquid matrices showed considerable advantages over conventional for MALDI-MS acidic compounds. Two new (ILMs) based on combination 2-(4-hydroxyphenylazo)benzoic...

Abstract Cyclodextrin poly‐functionalization has fueled progress in their use multiple applications such as enzyme mimicry, but also the polymer sciences, luminescence, sensors or for biomedical applications. However, regioselective access to a given pattern of functions on β‐cyclodextrin is still very limited. We uncover new orienting group, thioacetate, that expands toolbox available cyclodextrin poly‐hetero‐functionalization using diisobutylaluminum hydride (DIBAL‐H) promoted...

The analysis of the microstructure supramolecular copolymers is difficult because their dynamic character. Here, benzene‐1,3,5‐tricarboxamide (BTA) co‐assemblies are analysed by ion mobility ‐ mass spectrometry (IM‐MS) to reveal presence various sequences. For example, IM‐MS mobilogram for hexamers composed 4 units from a first monomer and 2 second broad distribution due 9 possible isomeric sequences, which can be sorted out based on calculated collision cross‐sections. This approach gives...

ABSTRACT Rationale Poly (acrylates)s can be distinguished from one another by the nature of their side chains. From model poly (acrylates)s, purpose this work was to evaluate contribution alternative activation techniques collisional activation, based on ion–ion and ion–photon interactions. Methods Sodiated (acrylate)s produced electrospray were isolated in an ion trap then submitted interactions with fluoranthene anions (by electron transfer dissociation) or UV photons (from a synchrotron...

The role of serotonin (5-HT)1B receptors in the mechanism action selective re-uptake inhibitors (SSRI) was studied by using intracerebral vivo microdialysis conscious, freely moving wild-type and 5-HT1B receptor knockout (KO 5-HT1B) mice order to compare effects chronic administration paroxetine via osmotic minipumps (1 mg per kg day for 14 days) on extracellular 5-HT levels ([5-HT]ext) medial prefrontal cortex ventral hippocampus. Basal [5-HT]ext values hippocampus, approximately 20 h after...

RATIONALE Carbohydrates have essential functions in living organisms and cells, but, due to the presence of numerous linkage combinations, substituent sites possible conformations, they are class biomolecules which exhibits huge structural diversity found nature. Thereby, such poor ionization, their deciphering by mass spectrometry is still a very challenging task. METHODS Here, we studied series linear cyclic neutral oligosaccharides using electrospray with collision‐induced dissociation...

Biomimetic membrane channels offer a great potential for fundamental studies and applications. Here, we report the fabrication characterization of short cyclodextrin nanotubes, their insertion into membranes, cytotoxicity assay. Mass spectrometry high-resolution transmission electron microscopy were used to confirm synthesis pathway leading formation nanotubes describe structural parameters in terms length, diameter, number cyclodextrins. Our results show control cyclodextrins threaded on...