A5026644032- DNA and Nucleic Acid Chemistry
- Molecular spectroscopy and chirality
- Crystallography and molecular interactions
- Protein Structure and Dynamics
- Analytical Chemistry and Chromatography
- Veterinary Oncology Research
- Mass Spectrometry Techniques and Applications
- Gold and Silver Nanoparticles Synthesis and Applications
- Enzyme Structure and Function
- Cancer Research and Treatments
- Spectroscopy and Quantum Chemical Studies
- RNA and protein synthesis mechanisms
- Clostridium difficile and Clostridium perfringens research
- Carbohydrate Chemistry and Synthesis
- Neuroendocrine Tumor Research Advances
- Protease and Inhibitor Mechanisms
- Nanocluster Synthesis and Applications
- Nanoparticle-Based Drug Delivery
- Advanced biosensing and bioanalysis techniques
- Chemical Reaction Mechanisms
- RNA Interference and Gene Delivery
- Bacterial Genetics and Biotechnology
- Gut microbiota and health
- Chemical Synthesis and Analysis
- Bacterial Infections and Vaccines
Inserm
2022-2024
Laboratoire de Recherche Vasculaire Translationnelle
2022-2024
Iowa State University
2020-2024
Université Sorbonne Paris Nord
2013-2024
Sorbonne Université
2004-2024
Hospital General de Elda
2024
Colorado State University
2016-2021
Centre National de la Recherche Scientifique
2003-2020
Université Paris Cité
2011-2020
Université de Reims Champagne-Ardenne
2017-2020
Thanks to a considerable modulation of electronic polarizability, six phenylalanine (Phe) vibration modes located at ca . 1606, 1586, 1207, 1031, 1004 and 622 cm −1 appear as intense or medium bands in the Raman spectra peptides proteins, confirmed by data collected from free amino acid, somatostatin bovine serum albumin (BSA). To get information on nature location these lines, we resorted multiconformational analysis which consists systematic investigation structural vibrational features...
Raman data collected from free amino acid and peptide chains permit assignment of the seven markers located at approximately 1616, 1606, 1210, 1178, 850, 830, 643 cm −1 to tyrosine. The effects induced by labile hydrogen deuteration, temperature, concentration, protonation–deprotonation on these were analyzed. Following closely a recent multiconformational analysis phenylalanine, we could confirm predominance gauche ‐ / rotamers with respect side chain χ 1 2 torsion angles in both tyrosine...
Ulcerative colitis is a chronic condition in which dysregulated immune response contributes to the acute intestinal inflammation of colon. Current clinical therapies often exhibit limited efficacy and undesirable side effects. Here, programmable nanomicelles were designed for treatment loaded with RU.521, an inhibitor cyclic GMP-AMP synthase-stimulator interferon genes (cGAS-STING) pathway. STING-inhibiting micelles (SIMs) comprise hyaluronic acid-stearic acid conjugates include reactive...
Four out of the 20 natural α-amino acids (α-AAs) contain aromatic rings in their side chains. In a recent paper (J. Phys. Chem. B 2010, 114, 9072-9083), we have analyzed structural and vibrational features l-histidine, one potent elements this series. Here, report on three remaining members family, i.e., l-phenylalanine, l-tyrosine, l-tryptophan. Their solution (H(2)O D(2)O) Raman scattering Fourier transform infrared absorption attenuated total reflection (FT-IR ATR) spectra were measured...
In relation with the difficulties encountered in previous works concerning preservation of S–S linkage cystine (Cys-Cys dimer) on Ag nanoparticles (NPs), we present here a systematic investigation both cysteine and as function various parameters governing preparation metal substrates. Surface-enhanced Raman scattering (SERS) was used probe for analyzing (i) integrity disulfide bonds adsorbed dimers, (ii) influence nature, reduction protocol well Cys-Cys concentration adsorption, (iii)...
Abstract A new method based on ultra‐performance liquid chromatography (UPLC) quadrupole time‐of‐flight mass spectrometry ((Q‐ToF)‐MS) was developed for the analysis of 32 biologically active compounds including anti‐inflammatories, analgesics, lipid regulators, psychiatric drugs, anti‐ulcer agents, antibiotics, beta‐blockers and phytoestrogens. This allows chromatographic in 14 min, with instrumental detection limits from 2 to 84 pg, quantification ranging 0.1 15 ng/L tap water, 300...
Abstract Many Gram-negative bacteria use Type I secretion systems, T1SS, to secrete virulence factors that contain calcium-binding Repeat-in-ToXin (RTX) motifs. Here, we present structural models of an RTX protein, RD, in both its intrinsically disordered calcium-free Apo-state and folded calcium-bound Holo-state. Apo-RD behaves as a polymer chain comprising several statistical elements exhibit local rigidity with residual secondary structure. Holo-RD is multi-domain protein anisometric...
Raman scattering and Fourier-transform infrared (FT−IR) attenuated transmission reflectance (ATR) spectra of two α-amino acids (α-AAs), i.e., glycine leucine, were measured in H2O D2O (at neutral pH pD). This series observed vibrational data gave us the opportunity to analyze features both AAs hydrated media by density functional theory (DFT) calculations at B3LYP/6-31++G* level. Harmonic modes calculated after geometry optimization on clusters containing each AA 12 surrounding water...
In the framework of our investigations on analysis vibrational spectra amino acids (AAs) in hydrated media, Raman scattering and Fourier transform infrared (FT-IR) attenuated transmission reflectance (ATR) three α-amino with hydrophobic hydrocarbon side chains, i.e., alanine, valine, isoleucine, were measured H2O D2O solutions. The present data complete those recently published by group glycine leucine. This series observed gave us opportunity to analyze features these media means density...
In two recent reports of the same series (J. Phys. Chem. B 2007, 111, 1470−1477 and J. 2009, 113, 3169−3178), we have described geometrical vibrational analysis glycine amino acids (AAs) with hydrophobic side chains through joint use optical spectroscopy quantum mechanical calculations. Here, report Raman scattering Fourier-Transform Infrared (FT-IR) Attenuated Total Reflectance (ATR) spectra measured from aqueous solutions (H2O D2O) l-lysine l-arginine, i.e. α-AAs positively charged...
During the last decades, Raman spectroscopy has been routinely used for probing conformational features of disulfide linkages in peptides and proteins. However, interpretation markers is currently performed by a simple rule derived from earliest observations on dialkyl disulfides. More precisely, this consists following: (1) analyzing bands 550–500 cm −1 region ascribed to bond stretch motion, namely, ν (S‐S), (2) assigning three types observed at ~500, ~520, ~540 families rotamers defined...
Transitional cell carcinoma (TCC) of the bladder comprises 2% diagnosed canine cancers. TCC tumors are generally inoperable and unresponsive to traditional chemotherapy, indicating a need for more effective therapies. BRAF, kinase in mitogen-activated protein (MAPK) pathway, is mutated 70% TCCs. In this study, we use BRAF mutant wild-type lines characterize role mutations pathogenesis assess efficacy inhibition MAPK pathway alone combination with other gene targets as treatment TCC. Analysis...
Gastrointestinal illnesses and dysbiosis are among the most common comorbidities reported in patients with neurodevelopmental disorders. The manuscript reports that C. difficile infection (CDI), predisposed by antibiotic-induced gut dysbiosis, causes significant alterations dopamine metabolism major dopaminergic brain regions mice (P < 0.05). In addition, infected exhibited significantly reduced beta-hydroxylase (DBH) activity compared to controls 0.01). Moreover, a increased serum...
Some significant prehistoric paintings from the Los Murciélagos cave (Zuheros, Córdoba, Spain) have been studied by Raman microscopy in order to determine nature of pigments used. Amorphous carbon (charcoal) has found black pictographs and haematite (α-Fe2O3) red ones. Clear differences between degrees alteration on several types surfaces are observed. Therefore, samples corresponding rock substrata, walls floor taken analysed IR spectroscopy. The painted panels, is essentially calcite....
In manuscript VI of the same series (J. Phys. Chem. B 2010, 114, 1077-1088), we reported geometrical and vibrational features lysine arginine, that is, two alpha-amino acids (alpha-AAs) with positively charged side chains, at physiological conditions. Here, report our results on histidine, one most biologically important alpha-AAs, whose chain can be neutral or through a protonation-deprotonation process nitrogens involved in its cyclic pH values range. We have recorded room temperature...
A comprehensive description of the energetic, conformational, and vibrational features two amino acids (AAs) with polar side chains, i.e., serine threonine, in aqueous environment, is provided. To adequately analyze chain conformational flexibility these acids, we resorted to quantum mechanical calculations use density functional theory, which allowed determination energetic AAs through 236 clusters. Each cluster contains a zwitterionic AA surrounded by seven explicit water molecules. The...
We present a set of new data allowing elucidation the energetic, conformational and vibrational features cysteine (Cys) methionine (Met), i.e. two natural amino acids (AAs) containing sulfur atom in their side chains. Special attention has been paid to cysteine, for which were analysed wide pH range (6-to-12), where its backbone can switch from zwitterionic an anionic form, chain SH group be deprotonated. Through detailed discussion on relative acidity three protonation sites this AA, as...
Despite numerous investigations devoted to the control of peptide and protein self-assemblies using nanostructured materials, molecular details peptide-material interaction sites remain still under debate. Here, we suggest a solution by jointly middle- low wavenumber regions surface-enhanced Raman spectra. To achieve our goal, adequately prepared gold silver colloids, which nanofabrication was controlled means zeta potential extinction spectra, were used enhance signal arising from natural...
Transitional cell carcinoma (TCC), also known as urothelial carcinoma, is the most common bladder cancer in humans and dogs. Approximately one-quarter of human TCCs are muscle-invasive associated with a high risk death from metastasis. Canine TCC (cTCC) tumours typically high-grade muscle-invasive. Shared similarities factors, histopathology, clinical presentation suggest that cTCC may serve model for assessment novel therapeutics inform therapies TCC. The goal this study was to characterize...
Experimental conditions favoring the tryptophan tight binding to surface of citrate-reduced gold nanoparticles (Cit-AuNPs) were explored. For this, adsorption three molecular compounds, free amino acid (Trp), tripeptide NH2-Gly-Trp-Gly-CONH2, and lanreotide, a synthetic cyclic somatostatin analogue, on large-size (∼70 nm) Cit-AuNPs was analyzed. UV–visible absorption, transmission electron microscopy, surface-enhanced Raman scattering (SERS) jointly used in present investigation. At low pH...
Octreotide, a potent somatostatin (SST) analogue, is used as an antiproliferative drug in numerous endocrine tumors. Previous NMR investigations, basically performed DMSO, had evidenced type-II' β-turn structure for this cyclic peptide. However, apart few incomplete studies by circular dichroism, systematic analysis of the structural behavior octreotide aqueous solution function concentration and ionic strength was still lacking. Here, we report chemical synthesis purification optical...