A5052858193- Enzyme Structure and Function
- Protein Structure and Dynamics
- RNA and protein synthesis mechanisms
- Mass Spectrometry Techniques and Applications
- X-ray Diffraction in Crystallography
- Lipid Membrane Structure and Behavior
- Crystallization and Solubility Studies
- RNA Research and Splicing
- Nuclear Structure and Function
- Supramolecular Self-Assembly in Materials
- Ion channel regulation and function
- Photosynthetic Processes and Mechanisms
- Microfluidic and Capillary Electrophoresis Applications
- Nicotinic Acetylcholine Receptors Study
- Advanced Cellulose Research Studies
- Silk-based biomaterials and applications
- DNA and Nucleic Acid Chemistry
- Alzheimer's disease research and treatments
- Advanced NMR Techniques and Applications
- Electrochemical Analysis and Applications
- Antibiotic Resistance in Bacteria
- Ubiquitin and proteasome pathways
- Bacterial Genetics and Biotechnology
- RNA modifications and cancer
- Innovative Microfluidic and Catalytic Techniques Innovation
Institut Laue-Langevin
2016-2025
Institut Langevin
2018-2024
European Synchrotron Radiation Facility
2007-2021
SLAC National Accelerator Laboratory
2010-2014
Stanford Synchrotron Radiation Lightsource
2010-2014
Stanford University
2012-2014
CEA Grenoble
2012
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2012
Centre National de la Recherche Scientifique
2012
Université Grenoble Alpes
2012
We have characterized the steps involved in silk assembly from protein solution into β-type fibers by a combination of small-angle and wide-angle X-ray scattering Raman spectroscopy. The aggregation process was studied concentric flow microfluidic cell, which allows mimicking spinning duct. fibroin molecule shows an elongated shape with maximum diameter 38 nm. During pH-driven initial step, large-scale aggregates molecules about 260 nm are formed. spectroscopy on dried, fibrous material...
Some styrene/maleic acid (SMA) copolymers solubilise membrane lipids and proteins to form polymer-bounded nanodiscs termed SMA/lipid particles (SMALPs). Although SMALPs preserve a lipid-bilayer core, they appear be more dynamic than other mimics. We used time-resolved Förster resonance energy transfer small-angle neutron scattering determine the kinetics mechanisms of phospholipid among SMALPs. In contrast with vesicles or protein-bounded nanodiscs, exchange not only by monomer diffusion but...
Abstract Structural crystallography and nuclear magnetic resonance (NMR) spectroscopy are the predominant techniques for understanding biological world on a molecular level. Crystallography is constrained by ability to form crystal that diffracts well NMR smaller proteins. Although powerful techniques, they leave many soluble, purified structurally uncharacterized protein samples. Small angle X‐ray scattering (SAXS) solution technique provides data size multiple conformations of sample, can...
A fully automated high-throughput solution X-ray scattering data collection system has been developed for protein structure studies at beamline 4-2 of the Stanford Synchrotron Radiation Lightsource. It is composed a thin-wall quartz capillary cell, syringe needle assembly on an XYZ positioning arm sample delivery, water-cooled rack and computer-controlled fluid dispenser. controlled by specifically software component built into standard control program Blu-Ice/DCS. The integrated intuitive...
Abstract Compact myelin comprises most of the dry weight myelin, and its insulative nature is basis for saltatory conduction nerve impulses. The major dense line (MDL) a 3-nm compartment between two cytoplasmic leaflets stacked membranes, mostly occupied by basic protein (MBP) phase. MBP an abundant involved in demyelinating diseases, such as multiple sclerosis. association with lipid membranes has been studied decades, but MBP-driven formation MDL remains elusive at biomolecular level. We...
Understanding adaptation to extreme environments remains a challenge of high biotechnological potential for fundamental molecular biology. The cytosol many microorganisms, isolated from saline environments, reversibly accumulates molar concentrations the osmolyte ectoine counterbalance fluctuating external salt concentrations. Although they have been studied extensively by thermodynamic and spectroscopic methods, direct experimental structural data have, so far, lacking on...
The nuclear pore complex (NPC) is the sole passageway for transport of macromolecules across envelope. Nup133, a major component in essential Y-shaped Nup84 complex, large scaffold protein NPC's outer ring structure. Here, we describe an integrative modeling approach that produces atomic models multiple states Saccharomyces cerevisiae (Sc) based on crystal structures sequence segments and their homologs, including related Vanderwaltozyma polyspora (Vp) Nup133 residues 55 to 502...
The first implementation and use of an in situ size exclusion chromatography (SEC) system on a small-angle neutron scattering instrument (SANS) is described. possibility deploying such for biological solution at the Institut Laue-Langevin (ILL) has arisen from fact that current day SANS instruments ILL now allow datasets to be acquired using small sample volumes with exposure times are often shorter than minute. This capability particular importance study unstable macromolecules where...
Abstract The myelin sheath is an essential, multilayered membrane structure that insulates axons, enabling the rapid transmission of nerve impulses. tetraspan proteolipid protein (PLP) most abundant compact in central nervous system (CNS). integral PLP adheres membranes together and enhances compaction myelin, having a fundamental role stability axonal support. linked to severe CNS neuropathies, including inherited Pelizaeus-Merzbacher disease spastic paraplegia type 2, as well multiple...
The presence of amyloid fibrils is a hallmark several neurodegenerative diseases. Some amyloidogenic proteins, such as α-synuclein and β, interact with lipids, this interaction can strongly favour the formation fibrils. In particular primary nucleation step,
The thermal behavior up to degradation of Bombyx mori silk has been studied by scanning synchrotron radiation microdiffraction, gel electrophoresis, and mechanical testing. diffraction patterns from single baves can be separated into scattering anisotropic crystalline beta-sheet domains random short-range order. In contrast dragline silk, oriented, short-range-order fibroin is not observed. sheath sericin proteins selectively probed a microbeam shows also principally with small fraction....
A novel and generally applicable method for determining structures of membrane proteins in solution via small‐angle neutron scattering (SANS) is presented. Common detergents solubilizing were synthesized isotope‐substituted versions utilizing the intrinsic length difference between hydrogen deuterium. Individual hydrogen/deuterium levels detergent head tail groups achieved such that formed micelles became effectively invisible heavy water (D 2 O) when investigated by neutrons. This way, only...
Many subsurface microorganisms couple their metabolism to the reduction or oxidation of extracellular substrates. For example, anaerobic mineral-respiring bacteria can use external metal oxides as terminal electron acceptors during respiration. Porin–cytochrome complexes facilitate movement electrons generated through intracellular catabolic processes across bacterial outer membrane these acceptors. In mineral-reducing model bacterium Shewanella oneidensis MR-1, this complex is composed two...
Influenza A RNA polymerase complex is formed from three components, PA, PB1, and PB2. PB2 independently imported into the nucleus prior to reconstitution. All crystallographic structures of C-terminus (residues 536-759) reveal two globular domains, 627 NLS, that form a tightly packed heterodimer. The molecular basis affinity 627-NLS for importins remained unclear these structures, apparently requiring large-scale conformational changes importin binding. Using combination solution-state NMR,...
Islet amyloid polypeptide (IAPP) is responsible for cell depletion in the pancreatic islets of Langherans, and multiple pathological consequences encountered by patients suffering from type 2 Diabetes Mellitus. We have examined amyloidogenicity cytotoxic mechanisms this peptide investigating model-membrane permeation structural effects fragments human IAPP several rat mutants. In vitro experiments molecular dynamics simulations reveal distinct physical segregation, membrane permeation,...
Small-angle neutron scattering (SANS) was used to examine dilute solutions of a poly(quinoxaline-2,3-diyl) (PQX) with (R)-2-octyloxymethyl side chains in deuterated THF or mixture 1,1,2-TCE and (8/2, v/v), which the PQX adopts pure P- M-helical structures. The structures that were obtained based on SANS experiments combination theoretical calculations suggest THF, chiral P-helical are extended, whereas 1,1,2-TCE/THF mixture, folded. Consequently, should be preferred good solvents such as...
Small-angle neutron scattering (SANS) is maturing as a method for studying complex biological structures. Owing to the intrinsic ability of technique discern between 1H- and 2H-labelled particles, it especially useful contrast-variation studies systems containing multiple components. SANS complementary small-angle X-ray (SAXS), in which similar contrast variation not easily performed but data with superior counting statistics are more obtained. Obtaining (SAS) on monodisperse structures...
Abstract All organisms depend on specific proteins to compact and organize their genomes. In eukaryotes, histones fulfil this role, while bacterial chromosomes are shaped by nucleoid-associated (NAPs). Among its pleiotropic functions, the NAP Hfq plays a pivotal role in genome organization. study, we characterized structure of C-terminal extension Hfq, which mediates chromosomal compaction, DNA-bound state. Using an integrative approach that combined transmission electron microscopy, neutron...
Abstract Understanding and engineering the flow-response of complex non-Newtonian fluids at a molecular level is key challenge for their practical utilisation. Here we demonstrate coupling microfluidics with small angle neutron scattering (SANS). Microdevices high transmission (up to 98%), low background ("Equation missing"<!-- image only, no MathML or LaTex -->), broad solvent compatibility pressure tolerance (≈3–15 bar) are rapidly prototyped via frontal photo polymerisation. Scattering...
Cellulose from grasses and cereals makes up much of the potential raw material for biofuel production. It is not clear if cellulose microfibrils differ in structure those other plants. The structures highly oriented cell walls internodes bamboo Pseudosasa amabilis are reported. Strong orientation facilitated use a range scattering techniques. Small-angle neutron provided evidence extensive aggregation by hydrogen bonding through hydrophilic edges sheets chains. had mean centre-to-centre...
Small-angle neutron scattering (SANS) is a powerful technique for the characterisation of macromolecular structures and interactions. Its main advantage over other solution state approaches ability to use D2O/H2O solvent contrast variation selectively match out specific parts multi-component system. While proteins, nucleic acids, lipids are readily distinguished in this way, it not possible locate different protein–protein system without introduction additional by selective deuteration....
Small-angle X-ray scattering (SAXS) has grown in popularity recent times with the advent of bright synchrotron sources, powerful computational resources and algorithms enabling calculation increasingly complex models. However, lack standardized data-quality metrics presents difficulties for growing user community accurately assessing quality experimental SAXS data. Here, a series to quantitatively describe data an objective manner using statistical evaluations are defined. These applied...