A5012030106- Light effects on plants
- Spectroscopy and Quantum Chemical Studies
- Photosynthetic Processes and Mechanisms
- Photochemistry and Electron Transfer Studies
- Photoreceptor and optogenetics research
- Advanced NMR Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- X-ray Diffraction in Crystallography
- Advanced Chemical Physics Studies
- Advanced X-ray Imaging Techniques
- Particle Accelerators and Free-Electron Lasers
- Advanced Electron Microscopy Techniques and Applications
- Biocrusts and Microbial Ecology
- Enzyme Structure and Function
- NMR spectroscopy and applications
- DNA and Nucleic Acid Chemistry
- Porphyrin and Phthalocyanine Chemistry
- Material Dynamics and Properties
- Luminescence and Fluorescent Materials
- bioluminescence and chemiluminescence research
- Plant and Biological Electrophysiology Studies
- Protein Structure and Dynamics
- Chemical and Physical Studies
- Electron Spin Resonance Studies
- Nonlinear Dynamics and Pattern Formation
Technical University of Denmark
2023-2024
University of Washington
2023-2024
University of Gothenburg
2019-2024
Kiel University
2015-2020
Phytochrome proteins control the growth, reproduction, and photosynthesis of plants, fungi, bacteria. Light is detected by a bilin cofactor, but it remains elusive how this leads to activation protein through structural changes. We present serial femtosecond X-ray crystallographic data chromophore-binding domains bacterial phytochrome at delay times 1 ps 10 after photoexcitation. The reveal twist D-ring, which partial detachment chromophore from protein. Unexpectedly, conserved so-called...
Abstract Charge-transfer reactions in proteins are important for life, such as photolyases which repair DNA, but the role of structural dynamics remains unclear. Here, using femtosecond X-ray crystallography, we report changes that take place while electrons transfer along a chain four conserved tryptophans Drosophila melanogaster (6-4) photolyase. At femto- and picosecond delays, photoreduction flavin by first tryptophan causes directed responses at key asparagine, salt bridge,...
Resolving the structural dynamics of initial steps chemical reactions is challenging. We report femtosecond time-resolved wide-angle x-ray scattering photodissociation diiodomethane in cyclohexane. The data reveal with detail how molecule dissociates into radicals, radicals collide solvent, and they form photoisomer. extract translational rotational kinetic energy dispersed solvent. also find that 85% primary radical pairs are confined to their original solvent cage discuss this influences...
Resolving the structural dynamics of bond breaking, formation, and solvation is required for a deeper understanding solution-phase chemical reactions. In this work, we investigate photodissociation triiodide in four solvents using femtosecond time-resolved X-ray solution scattering following 400 nm photoexcitation. Structural analysis data resolves solvent-dependent evolution during cleavage, internal rearrangements, solvent-cage escape, reformation real time. The nature structure reaction...
X-ray free-electron lasers (XFELs) can probe chemical and biological reactions as they unfold with unprecedented spatial temporal resolution. A principal challenge in this pursuit involves the delivery of samples to interaction point such a way that produces data highest possible quality maximal efficiency. This is hampered by intrinsic constraints posed light source operation within beamline environment. For liquid samples, solution typically some form high-speed jet, capable keeping up...
The structural response of the drosophila (6-4) photolyase to photoinduced electron transfer along a chain tryptophans is revealed using serial crystallographic snapshot protein in its radical pair state.
Structural studies using x-ray scattering methods for investigating molecules in solution are shifting focus toward describing the role and effects of surrounding solvent. However, forward models based on molecular dynamics (MD) simulations to simulate structure factors from interatomic distributions such as radial distribution functions (RDFs) face limitations imposed by simulations, particularly at low values vector q. In this work, we show how value factor q = 0 calculated RDFs sampled...
This work investigates and describes the structural dynamics taking place following charge-transfer-to-solvent photo-abstraction of electrons from I- Br- ions in aqueous solution single- 2-photon excitation at 202 nm 400 nm, respectively. A Time-Resolved X-ray Solution Scattering (TR-XSS) approach with direct sensitivity to structure surrounding solvent as water molecules adopt a new equilibrium configuration electron-abstraction process is utilized investigate shell expansion restructuring...
Abstract Detecting microsecond structural perturbations in biomolecules has wide relevance biology, chemistry and medicine. Here we show how MHz repetition rates at X-ray free-electron lasers can be used to produce time-series of protein scattering with exceptionally low noise levels 0.001%. We demonstrate the approach by examining Jɑ helix unfolding a light-oxygen-voltage photosensory domain. This time-resolved acquisition strategy is easy implement widely applicable for direct observation...
(6–4) photolyases are flavoproteins that belong to the photolyase/cryptochrome family. Their function is repair DNA lesions using visible light. Here, crystal structures of Drosophila melanogaster photolyase [ Dm (6–4)photolyase] at room and cryogenic temperatures reported. The room-temperature structure was solved 2.27 Å resolution obtained by serial femtosecond crystallography (SFX) an X-ray free-electron laser. crystallization preparation conditions also 1.79 conventional crystallography....
Proton transfer processes build the foundation of many chemical processes. In excited state intramolecular proton (ESIPT) processes, ultrafast is impulsively initiated through light. Here, we explore time-dependent coupled atomic and electronic motions during following ESIPT computational time-resolved resonant inelastic X-ray scattering (RIXS). Excited-state ab initio molecular dynamics simulations combined with density functional theory calculations were performed for a model complex,...
Proton transfer processes form the foundation of many chemical processes. In excited-state intramolecular proton (ESIPT) processes, ultrafast is impulsively initiated through light. Here, we explore time-dependent coupled atomic and electronic motions during following ESIPT computational time-resolved resonant inelastic X-ray scattering (RIXS). Excited-state ab initio molecular dynamics simulations combined with density functional theory calculations were performed for a model system,...
Structural studies using x-ray scattering methods to investigate molecules in solution are shifting focus towards including the role and effects of surrounding solvent. However, forward models based on molecular dynamics (MD) simulations simulate structure factors from interatomic distributions such as radial distribution functions (RDFs) face limitations imposed by simulations, particularly at low values vector q. In this work, we show how value factor q = 0 calculated RDFs sampled finite...
Structural studies using x-ray scattering methods for investigating molecules in solution are shifting focus towards describing the role and effects of surrounding solvent. However, forward models based on molecular dynamics (MD) simulations to simulate structure factors from interatomic distributions such as radial distribution functions (RDFs) face limitations imposed by simulations, particularly at low values vector q. In this work, we show how value factor q = 0 calculated RDFs sampled...
Phytochrome proteins control the growth, reproduction, and photosynthesis of plants, fungi, bacteria. Light is detected by a bilin cofactor, but it remains elusive how this leads to activation protein through structural changes. We present serial femtosecond X-ray crystallographic data chromophore-binding domains bacterial phytochrome at delay times 1 ps 10 after photoexcitation. The structures reveal twist D-ring, which lead partial detachment chromophore from protein. Unexpectedly,...
<title>Abstract</title> Detecting microsecond structural perturbations in biomolecules has wide relevance biology, chemistry, and medicine. Here, we show how MHz repetition rates at X-ray free electron lasers (XFELs) can be used to produce time-series of protein scattering with exceptionally low noise levels 0.001%. We demonstrate the approach by deriving new mechanistic insight into Jα helix unfolding a Light-Oxygen-Voltage (LOV) photosensory domain. This time-resolved acquisition strategy...
Abstract Ein Bericht über ein Forschungspraktikum in Vietnam
X-ray Free Electron Lasers (XFELs) can probe chemical and biological reactions as they unfold with unprecedented spatial temporal resolution. A principal challenge in this pursuit is the delivery of samples to interaction point a way that produces data highest possible quality efficiency. This hampered by constraints posed light source operation within beamline environment. For liquid samples, solution typically involves high-speed jet, capable keeping up rate pulses. However, conventional...
Phytochromes are photoreceptor proteins that detect red and far-red light in plants, fungi bacteria.Light absorption by a bilin
Abstract Charge transfer reactions in proteins are fundamentally important for life, but it is currently not clear how protein structural dynamics control these electron reactions. Photolyases/cryptochromes, which repair DNA and signal all kingdoms of have a paradigm cascade. Here, photoreduction the flavin cofactor initiates charge along chain four conserved tryptophans. We report femtosecond X-ray crystallographic snap-shots Drosophila melanogaster (6-4) photolyase, revealing changes while...
Transient vibrational absorption spectroscopy elucidates common deactivation pathways after UV photoexcitation for 7- and 9-methylpurine. However, 9-methylpurine exhibits an additional relaxation channel revealed by indirect observation of the excited 1 ππ* state