Register training material
3 materials found

Related resources: Slides 


Neutrons for Magnetic Nanostructures on Surfaces: Beyond the Specular Intensity Wars

Polarized Neutron Reflectometry (PNR) is a great method to study magnetism of surface near structures on the nm scale. It is especially useful for functional materials and fundamentals of nano magnetism. The applications of the technique and the related grazing incidence scattering include...

Scientific topics: polarized neutron reflectometry, grazing incidence small angle neutron scattering

Keywords: polarized neutron reflectometry, grazing incidence scattering, magnetic nanoparticles, GISANS

Resource type: video, slides

Neutrons for Magnetic Nanostructures on Surfaces: Beyond the Specular Intensity Wars https://pan-training.eu/materials/neutrons-for-magnetic-nanostructures-on-surfaces-beyond-the-specular-intensity-wars Polarized Neutron Reflectometry (PNR) is a great method to study magnetism of surface near structures on the nm scale. It is especially useful for functional materials and fundamentals of nano magnetism. The applications of the technique and the related grazing incidence scattering include multiferroic heterostructures, correlated electron systems, exchange bias, superconductors, magnetic nanoparticles and spin textures like skyrmions. Many of these systems have in common that the sample sizes are small, leading to intensity limited experiments. [...] polarized neutron reflectometry grazing incidence small angle neutron scattering polarized neutron reflectometry, grazing incidence scattering, magnetic nanoparticles, GISANS
Seeing the chemistry in biology using neutron crystallography

New developments in macromolecular neutron crystallography have led to an increasing number of structures published over the last decade. Hydrogen atoms, normally invisible in most X-ray crystal structures, become visible in neutron structures. Using X-rays allows one to see structure, while...

Keywords: macromolecular neutron crystallography, biological macromolecules, neutron

Resource type: video, slides, scientific article

Seeing the chemistry in biology using neutron crystallography https://pan-training.eu/materials/seeing-the-chemistry-in-biology-using-neutron-crystallography New developments in macromolecular neutron crystallography have led to an increasing number of structures published over the last decade. Hydrogen atoms, normally invisible in most X-ray crystal structures, become visible in neutron structures. Using X-rays allows one to see structure, while neutrons allow one to reveal the chemistry inherent in these macromolecular structures. A number of surprising and sometimes controversial results have emerged from recent neutron structures; because it is difficult to see or predict hydrogen atoms in X-ray structures, when they are seen by neutrons they can be in unexpected locations with important chemical and biological consequences. Here we describe examples of chemistry seen with neutrons for the first time in biological macromolecules over the past few years. macromolecular neutron crystallography, biological macromolecules, neutron
Neutron crystallography to inform drug design targeting SARS-CoV-2 main protease

Talk from one of the ILL colloqia. See colloquia list at the bottom for other talks. COVID-19, caused by SARS-CoV-2, remains a global health threat after two years of the pandemic even with available vaccines and therapeutic options. The viral main protease (Mpro) is indispensable for the...

Keywords: COVID research, neutron, drug development, neutron crystallography

Resource type: video, slides

Neutron crystallography to inform drug design targeting SARS-CoV-2 main protease https://pan-training.eu/materials/neutron-crystallography-to-inform-drug-design-targeting-sars-cov-2-main-protease Talk from one of the ILL colloqia. See colloquia list at the bottom for other talks. COVID-19, caused by SARS-CoV-2, remains a global health threat after two years of the pandemic even with available vaccines and therapeutic options. The viral main protease (Mpro) is indispensable for the virus replication and thus is an important target for small-molecule antivirals. Computer-assisted and structure-based drug design strategies rely on atomic scale understanding of the target biomacromolecule traditionally derived from X-ray crystallographic data collected at cryogenic temperatures. Conventional protein X-ray crystallography is limited by possible cryo-artifacts and its inability to locate the functional hydrogen atoms crucial for understanding chemistry occurring in enzyme active sites. Neutrons are ideal probes to observe the protonation states of ionizable amino acids at near-physiological temperature, directly determining their electric charges – crucial information for drug design. Our room-temperature X-ray crystal structures of Mpro brought rapid insights into the reactivity of the catalytic cysteine, malleability of the active site, and binding modes with clinical protease inhibitors. The neutron crystal structures of ligand-free and inhibitor-bound Mpro were determined allowing the direct observation of protonation states of all residues in a coronavirus protein for the first time [1,2]. At rest, the catalytic Cys-His dyad exists in the reactive zwitterionic state (Fig. 1), with both Cys145 and His41 charged, instead of the anticipated neutral state. Covalent inhibitor binding results in modulation of the protonation states. This information was used to design nanomolar hybrid reversible covalent inhibitors with robust antiviral properties. High-throughput virtual screening, utilizing ORNL’s supercomputing capabilities, in conjunction with in vitro assays identified a lead noncovalent compound with sub-micromolar affinity. The neutron structure of Mpro in complex with the noncovalent inhibitor was used in a structure-activity relationship (SAR) study guided by virtual reality structure analysis to novel Mpro inhibitors with imporved affinity to the enzyme [3]. Our research is providing real-time data for atomistic design and discovery of Mpro inhibitors to combat the COVID-19 pandemic and prepare for future threats from pathogenic coronaviruses. [1] D.W. Kneller et al. Unusual zwitterionic catalytic site of SARS-CoV-2 main protease revealed by neutron crystallography. J. Biol. Chem.295, 17365-17373 (2020). [2] D.W. Kneller et al. Direct observation of protonation state modulation in SARS-CoV-2 main protease upon inhibitor binding with neutron crystallography. J. Med. Chem.64, 4991-5000 (2021). [3] D.W. Kneller et al. Structural, electronic and electrostatic determinants for inhibitor binding to subsites S1 and S2 in SARS-CoV-2 main protease. J. Med. Chem.64, 17366-17383 (2021). The authors acknowledge support by the National Virtual Biotechnology Laboratory, US Department of Energy. COVID research, neutron, drug development, neutron crystallography