A5085754261- Enzyme Structure and Function
- Photoreceptor and optogenetics research
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Physics and Applications
- Magnetism in coordination complexes
- Protein Structure and Dynamics
- Retinal Development and Disorders
- Advanced Electron Microscopy Techniques and Applications
- Advanced X-ray Imaging Techniques
- Receptor Mechanisms and Signaling
- Porphyrin Metabolism and Disorders
- Neural dynamics and brain function
- Heusler alloys: electronic and magnetic properties
- Force Microscopy Techniques and Applications
- bioluminescence and chemiluminescence research
- Lanthanide and Transition Metal Complexes
- Photosynthetic Processes and Mechanisms
- Inorganic Chemistry and Materials
- X-ray Diffraction in Crystallography
- Metal-Catalyzed Oxygenation Mechanisms
- Chemical Reactions and Isotopes
- Radioactive element chemistry and processing
- Mass Spectrometry Techniques and Applications
- Ion-surface interactions and analysis
- Atomic and Subatomic Physics Research
MAX IV Laboratory
2025
Lund University
2025
ETH Zurich
2022-2024
Paul Scherrer Institute
2016-2024
University of Wisconsin–Milwaukee
2022
Deutsches Elektronen-Synchrotron DESY
2022
Center for Free-Electron Laser Science
2022
Universität Hamburg
2022
Institut Laue-Langevin
2014-2016
Institut de Biologie Structurale
2016
Abstract Vision is initiated by the rhodopsin family of light-sensitive G protein-coupled receptors (GPCRs) 1 . A photon absorbed 11- cis retinal chromophore rhodopsin, which isomerizes within 200 femtoseconds to all- trans conformation 2 , thereby initiating cellular signal transduction processes that ultimately lead vision. However, intramolecular mechanism photoactivated induces activation events inside remains experimentally unclear. Here we use ultrafast time-resolved crystallography at...
Chloride transport by microbial rhodopsins is an essential process for which molecular details such as the mechanisms that convert light energy to drive ion pumping and ensure unidirectionality of have remained elusive. We combined time-resolved serial crystallography with spectroscopy multiscale simulations elucidate mechanism a chloride-pumping rhodopsin structural dynamics throughout cycle. traced transient anion-binding sites, obtained evidence how used in mechanism, identified steric...
Heme enzymes activate oxygen through formation of transient iron-oxo (ferryl) intermediates the heme iron. A long-standing question has been nature iron-oxygen bond and, in particular, protonation state. We present neutron structures ferric derivative cytochrome c peroxidase and its ferryl intermediate; these allow direct visualization states. demonstrate that is an Fe(IV)=O species not protonated. Comparison shows distal histidine becomes protonated on intermediate, which implications for...
Abstract The conservation and restoration of forest ecosystems require detailed knowledge the native plant compositions. Here, we map global tree composition assess impacts historical cover loss climate change on trees. occupancy 10,590 species reveals complex taxonomic phylogenetic gradients determining a local signature lineage assembly. Species analyses indicate that has significantly restricted potential suitable range in all biomes. Nevertheless, tropical moist boreal biomes display...
Abstract Catalytic heme enzymes carry out a wide range of oxidations in biology. They have common mechanism that requires formation highly oxidized ferryl intermediates. It is these intermediates provide the catalytic engine to drive biological activity. Unravelling nature species fundamental and widespread importance. The essential question whether best described as Fe(IV)=O or Fe(IV)–OH species, but previous spectroscopic X-ray crystallographic studies not been able unambiguously...
The first multi-bend achromat based synchrotron MAX IV operates two protein crystallography beamlines, BioMAX and MicroMAX. is designed as a versatile, stable, high-throughput beamline catering for most experiments. MicroMAX more ambitious dedicated to serial including time-resolved Both beamlines exploit the special characteristics of fourth-generation provided by 3 GeV ring IV. In addition, fragment-based drug discovery platform, FragMAX, hosted and, at FemtoMAX beamline, diffraction...
Long-wavelength pulses from the Swiss X-ray free-electron laser (XFEL) have been used for de novo protein structure determination by native single-wavelength anomalous diffraction (native-SAD) phasing of serial femtosecond crystallography (SFX) data. In this work, sensitive data-quality indicators and model proteins were to quantify improvements in native-SAD at XFELs such as utilization longer wavelengths, careful experimental geometry optimization, better post-refinement partiality...
We present 53Cr-NMR spectra collected at low temperature in a single crystal of the heterometallic antiferromagnetic (AF) ring Cr7Ni S = 1/2 ground state with aim establishing distribution local electronic moment ring. Due to poor S/N we observed only one signal which is ascribed three almost equivalent 53Cr nuclei The calculated spin density state, applied magnetic field both parallel and perpendicular plane ring, turns out be AF staggered greatest component 〈s〉 for Cr3+ ions next Ni2+ ion....
Low-pass spectral analysis (LPSA) is a recently developed dynamics retrieval algorithm showing excellent properties when applied to model data affected by extreme incompleteness and stochastic weighting. In this work, we apply LPSA an experimental time-resolved serial femtosecond crystallography (TR-SFX) dataset from the membrane protein bacteriorhodopsin (bR) analyze its parametric sensitivity. While most dynamical modes are contaminated nonphysical high-frequency features, identify two...
Previous proof-of-concept measurements on single-layer two-dimensional membrane-protein crystals performed at X-ray free-electron lasers (FELs) have demonstrated that the collection of meaningful diffraction patterns, which is not possible synchrotrons because radiation-damage issues, feasible. Here, results obtained from analysis a thousand single-shot, room-temperature FEL images bacteriorhodopsin mutant are reported in detail. The high redundancy boosts intensity signal-to-noise ratio, so...
Time-resolved serial femtosecond crystallography (TR-SFX) provides access to protein dynamics on sub-picosecond timescales, and with atomic resolution. Due the nature of experiment, these datasets are often highly incomplete measured diffracted intensities affected by partiality. To tackle issues, one established procedure is that splitting data into time bins, averaging multiple measurements equivalent reflections within each bin. This binning involve a loss information. Here, we propose an...
A detailed experimental investigation of the 19F nuclear magnetic resonance is made on single crystals homometallic Cr8 antiferromagnetic molecular ring and heterometallic Cr7Cd Cr7Ni rings in low temperature ground state. Since F− ion located midway between neighboring metal ions ring, 19F-NMR spectra yield information about local electronic spin density hyperfine interactions. In Cr8, where state a singlet with total ST = 0, at 1.7 K external field display narrow line, while when increased...
Abstract Vision is initiated by the rhodopsin family of light-sensitive G protein-coupled receptors (GPCRs). A photon absorbed 11- cis retinal chromophore which isomerises within 200 femtoseconds to all- trans conformation, thereby initiating cellular signal transduction processes that ultimately lead vision. However, intramolecular mechanism photoactivated induces activation events inside remains elusive. In this work, we use ultrafast time-resolved crystallography at room temperature...
Serial femtosecond crystallography (SFX) is a powerful technique for studying ultrafast structural dynamics in matter. However, the analysis of SFX data challenging and would benefit from systematic theoretical framework. By employing quantum-electrodynamics approach, we demonstrate that conventional practices are not only intuitively plausible but also firmly grounded well-established principles. We show standard assumptions remain valid even when non-Born-Oppenheimer effects near conical...
Rhodopsin is a G-protein-coupled receptor that detects light and initiates the intracellular signalling cascades underpin vertebrate vision. Light sensitivity achieved by covalent linkage to 11- cis retinal, which isomerizes upon photo-absorption. Serial femtosecond crystallography data collected from rhodopsin microcrystals grown in lipidic cubic phase were used solve room-temperature structure of receptor. Although diffraction showed high completeness good consistency 1.8 Å resolution,...
Serial femtosecond crystallography of two-dimensional membrane-protein crystals at X-ray free-electron lasers has the potential to address dynamics functionally relevant large-scale motions, which can be sterically hindered in three-dimensional and suppressed cryocooled samples. In previous work, diffraction data limited a reciprocal-space slice were evaluated it was demonstrated that low intensity signal overcome by collecting highly redundant data, thus enhancing achievable resolution....