A5089415691- Mass Spectrometry Techniques and Applications
- Atomic and Molecular Physics
- Ion-surface interactions and analysis
- Analytical Chemistry and Chromatography
- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Collagen: Extraction and Characterization
- Advanced Proteomics Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- DNA and Nucleic Acid Chemistry
- Radiation Therapy and Dosimetry
- Protein Structure and Dynamics
- Meat and Animal Product Quality
- Protein Hydrolysis and Bioactive Peptides
- Fullerene Chemistry and Applications
- Photochemistry and Electron Transfer Studies
- Enzyme Structure and Function
- Radiation Effects and Dosimetry
- Advanced biosensing and bioanalysis techniques
- Crystallization and Solubility Studies
- Molecular Sensors and Ion Detection
- Computational Drug Discovery Methods
- Chemical Synthesis and Analysis
- Microbial Natural Products and Biosynthesis
- Polymer Nanocomposite Synthesis and Irradiation
Centre de Recherche sur les Ions, les Matériaux et la Photonique
2016-2025
GANIL
2014-2025
Centre National de la Recherche Scientifique
2014-2024
École Nationale Supérieure d'Ingénieurs de Caen
2014-2024
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2014-2024
Université de Caen Normandie
2013-2024
Normandie Université
2018-2022
University of Groningen
2020
Université Sorbonne Paris Nord
2008-2013
Laboratoire de physique des lasers
2007-2013
We studied the photoionization of 2-pyridone and its tautomer, 2-hydroxypyridine by means VUV synchrotron radiation coupled to a velocity map imaging electron/ion coincidence spectrometer. The efficiency (PIE) spectrum is composed steps. state energies [2-pyridone]+ cation in ground à excited electronic states, as well [2-hydroxypyridine]+ state, are determined. slow photoelectron spectra (SPES) dominated 000 transitions corresponding states together with several weaker bands population pure...
We report highly selective covalent bond modifications in collisions between keV alpha particles and van der Waals clusters of ${\mathrm{C}}_{60}$ fullerenes. Surprisingly, $\mathrm{C}_{119}{}^{+}$ $\mathrm{C}_{118}{}^{+}$ are the dominant molecular fusion products. use dynamics simulations to show that $\mathrm{C}_{59}{}^{+}$ $\mathrm{C}_{58}{}^{+}$ ions---effectively produced prompt knockout processes with ${\mathrm{He}}^{2+}$---react rapidly form dumbbell $\mathrm{C}_{118}{}^{+}$. Ion...
DNA oligonucleotide ions forming G-quadruplex structures were studied in the gas phase using IRMPD spectroscopy. Data interpretation on these large biomolecule was made carefully chosen control experiments. The major finding is a fingerprint of hydrogen bonding guanine C6O6 stretching mode that allows probing conservation G-quartets phase. experiments demonstrate bonds human telomeric sequence d(TTAGGG)4.
The direct effects of ionizing radiation on antibiotics are largely unknown. Here, we report mass spectra the cationic products irradiation three by carbon ions at 10.4 MeV kinetic energy. Carbon ion beams used in cancer treatments have this energy when they deliver maximum dose to malignant cells. We find that upon single collision, extensive fragmentation occurs, predominantly through channels similar those observed soft X‐ray photoabsorption. However, new product also detected and...
The prediction accuracy of second-order Moller-Plesset theory MP2 and density functional DFT-(D) with without empirical dispersion correction within the resolution identity approximation (ri) have been investigated for assignment infrared spectra gas-phase peptides. A training set 17 conformers phenylalanine containing capped peptides used to establish mode-specific local scaling factors. Inclusion terms at DFT level turns significantly improve predicted IR spectra. At DFT-D level, nonhybrid...
Abstract Fragmentation of the γ‐aminobutyric acid molecule (GABA, NH 2 (CH ) 3 COOH) following collisions with slow O 6+ ions ( v ≈0.3 a.u.) was studied in gas phase by a combined experimental and theoretical approach. In experiments, multicoincidence detection method used to deduce charge state GABA before fragmentation. This is essential unambiguously unravel different fragmentation pathways. It found that molecular cations resulting from hardly survive interaction main dissociation...
Electron capture by both bare and microsolvated small peptide dications was investigated colliding these ions with sodium vapor in an accelerator mass spectrometer to provide insight into processes that occur on the microsecond time frame. Survival of intact monocation after electron depends strongly molecular size. For dipeptides, no reduced species were observed; predominant correspond loss hydrogen ammonia. In contrast, observed for larger peptides. Calculated structures indicate...
We report experimental results for the ionization and fragmentation of weakly bound van der Waals clusters n C60 molecules following collisions with Ar2 +, He2 Xe20 + at laboratory kinetic energies 13 keV, 22.5 300 respectively. Intact singly charged monomers are dominant reaction products in all three cases this is accounted by means Monte Carlo calculations energy transfer processes a simple Arrhenius-type \documentclass[12pt]{minimal}\begin{document}$[{\rm...
Charge localization within nucleosides after proton irradiation is strongly influenced by the ionization energy of base.
The gas-phase structures of doubly and triply protonated Amyloid-β12-28 peptides have been investigated through the combination ion mobility (IM), electron capture dissociation (ECD) mass spectrometry, infrared multi-photon (IRMPD) spectroscopy together with theoretical modeling. Replica-exchange molecular dynamics simulations were conducted to explore conformational space these peptides, from which several classes found. Among low-lying conformers, those predicted diffusion cross-sections...
Radical creation after single-photon ionisation of collagen peptides induces the loss molecules from amino-acid residue side-chains.
Abstract Collisions between O 3+ ions and neutral clusters of amino acids (alanine, valine glycine) as well lactic acid are performed in the gas phase, order to investigate effect ionizing radiation on these biologically relevant molecular systems. All monomers dimers found be predominantly protonated, ab initio quantum–chemical calculations model systems indicate that for acids, this is due proton transfer within after ionization. For acid, which has a lower affinity than significant...
Molecular fragmentation leading to the formation of negatively and positively charged hydrogen ions in 7-keV ${OH}^{+}$ + Ar collisions is investigated experimentally. The most striking finding that negative positive are emitted with very similar angular dependences. Also, kinetic energy distribution ${H}^{+}$ fragment shows strong similarities ejected ${H}^{\ensuremath{-}}$ ion. kinematics H core found be essentially driven by its scattering on atomic target. However, addition this...
Biomolecular recognition of vancomycin antibiotics with its cell-wall precursor analogue Ac(2)(L)K(D)A(D)A has been investigated in the gas phase through a combined laser spectroscopy/mass spectrometry approach. The mid-IR spectra (1100-1800 cm(-1)) these mass-selected anionic species have recorded by means resonant infrared multiphoton dissociation (IRMPD) spectroscopy performed free-electron CLIO. Structural assignment achieved comparisons low-energy conformers obtained from...
To fully understand the mechanisms of radiation damage in living tissues, a detailed knowledge processes occurring at molecular level is needed. In gas phase, most investigations concerning ionization and fragmentation biologically relevant systems are performed with isolated molecules. The importance such studies limited to intrinsic properties these molecules because lack chemical environment. probe effect an environment on behavior small biomolecules under irradiation, (α-amino acids,...
Cartilage and tendons owe their special mechanical properties to the fibrous collagen structure. These strong fibrils are aggregates of a sub-unit consisting three proteins wound around each other in triple helix. Even though is most abundant protein human body, response this complex ionizing radiation has never been studied. In work, we probe direct effects VUV soft X-ray photons on isolated models helix, by coupling tandem mass spectrometer synchrotron beamline. Single-photon absorption...
Abstract Little is known regarding radiation-induced matrikines and the possible degradation of extracellular matrix following therapeutic irradiation. The goal this study was to determine if irradiation can cut collagen proteins at specific sites, inducing potentially biologically active peptides against cartilage cells. Chondrocytes cultured as 3D models were evaluated for production. Bystander molecules analyzed in vitro conditioned medium X-irradiated chondrocytes. Preferential breakage...
Abstract The origin of the triple‐helix structure and high stability collagen has been debated for many years. As models triple helix building blocks new biomaterials, mimetic peptide (CMP) assemblies have deeply studied in condensed phase. In particular, it was found that hydroxylation proline, an abundant post‐translational modification collagen, increases its stability. Two main hypotheses emerged to account this behavior: 1) intra‐helix stereoelectronic effects, 2) role water molecules...
It is shown that negative ions are ejected from gas-phase water molecules when bombarded with positive at keV energies typical of solar-wind velocities. This finding relevant for studies planetary and cometary atmospheres, as well radiolysis radiobiology. Emission both ${\mathrm{H}}^{\ensuremath{-}}$ heavier (${\mathrm{O}}^{\ensuremath{-}}$ $\mathrm{O}{\mathrm{H}}^{\ensuremath{-}}$) anions, a larger yield ${\mathrm{H}}^{\ensuremath{-}}$, was observed in...
The prediction accuracy of the ONIOM method for interpretation infrared spectra gas-phase molecules biological interest has been investigated. With use experimental results concerning amino acids, small peptides, and sugars taken from literature, mode-specific local scaling factors have determined different high-layer/low-layer couples. A significant improvement is noticed when using with respect to global factors. B3LYP/6-31G*:AM1 level turns out offer best trade-off between computational...