M. Hilpert
A5045595600- Photoreceptor and optogenetics research
- Viral Infectious Diseases and Gene Expression in Insects
- Advanced X-ray Imaging Techniques
- Enzyme Structure and Function
- Hemoglobin structure and function
- Advanced Electron Microscopy Techniques and Applications
- Photosynthetic Processes and Mechanisms
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Strong Light-Matter Interactions
- Biofield Effects and Biophysics
- Semiconductor Quantum Structures and Devices
- Electron Spin Resonance Studies
- Advanced Fluorescence Microscopy Techniques
- Photonic Crystals and Applications
- Quantum and electron transport phenomena
- Chemical Reactions and Isotopes
- Atomic and Subatomic Physics Research
- Spectroscopy and Quantum Chemical Studies
- Photochromic and Fluorescence Chemistry
- Entomopathogenic Microorganisms in Pest Control
- Semiconductor materials and devices
- Insect Resistance and Genetics
- Advanced NMR Techniques and Applications
- Chalcogenide Semiconductor Thin Films
Max Planck Institute for Medical Research
2015-2024
Max Planck Society
1998-2021
University of Liverpool
2016
University of Vienna
2004
Max Planck Institute for Solid State Research
1996-1999
University of Würzburg
1994
The hemoprotein myoglobin is a model system for the study of protein dynamics. We used time-resolved serial femtosecond crystallography at an x-ray free-electron laser to resolve ultrafast structural changes in carbonmonoxy complex upon photolysis Fe-CO bond. Structural appear throughout within 500 femtoseconds, with C, F, and H helices moving away from heme cofactor E A toward it. These collective movements are predicted by hybrid quantum mechanics/molecular mechanics simulations. Together...
Abstract Bacteriorhodopsin (bR) is a light-driven proton pump. The primary photochemical event upon light absorption isomerization of the retinal chromophore. Here we used time-resolved crystallography at an X-ray free-electron laser to follow structural changes in multiphoton-excited bR from 250 femtoseconds 10 picoseconds. Quantum chemistry and ultrafast spectroscopy were identify sequential two-photon process, leading excitation tryptophan residue flanking chromophore, as first...
Light makes light work of fatty acids Photosynthetic organisms are notable for their ability to capture energy and use it power biosynthesis. Some algae have gone a step beyond photosynthesis can initiate enzymatic photodecarboxylation acids, producing long-chain hydrocarbons. To understand this transformation, Sorigué et al. brought bear an array structural, computational, spectroscopic techniques fully characterized the catalytic cycle enzyme. These experiments consistent with mechanism...
Abstract High-intensity femtosecond pulses from an X-ray free-electron laser enable pump–probe experiments for the investigation of electronic and nuclear changes during light-induced reactions. On timescales ranging femtoseconds to milliseconds a variety biological systems, time-resolved serial crystallography (TR-SFX) has provided detailed structural data isomerization, breakage or formation chemical bonds electron transfer 1,2 . However, all ultrafast TR-SFX studies date have employed...
Abstract X-ray free-electron lasers (XFELs) enable novel experiments because of their high peak brilliance and femtosecond pulse duration. However, non-superconducting XFELs offer repetition rates only 10–120 Hz, placing significant demands on beam time sample consumption. We describe serial crystallography performed at the European XFEL, first MHz rate delivering 1.128 trains 10 Hz. Given short spacing between pulses, damage caused by shock waves launched one XFEL probed subsequent pulses...
X-ray free-electron lasers (XFELs) enable crystallographic structure determination beyond the limitations imposed upon synchrotron measurements by radiation damage. The need for very short XFEL pulses is relieved through gating of Bragg diffraction loss crystalline order as damage progresses, but not if ionization events are spatially non-uniform due to underlying elemental distributions, in biological samples. Indeed, correlated movements iron and sulfur ions were observed XFEL-irradiated...
Circularly polarized optical excitation of a semiconductor microcavity in transverse magnetic field leads to pulsed laser emission with alternating circular polarization synchronized the electron Larmor precession. The synchronization originates from transfer electron-spin coherence dynamics field. A microscopic theory is developed analyze coupled carrier--light-field dynamics.
Crystallography chips are fixed-target supports consisting of a film (for example Kapton) or wafer silicon) that is processed using semiconductor-microfabrication techniques to yield an array wells through-holes in which single microcrystals can be lodged for raster-scan probing. Although relatively expensive fabricate, offer efficient means high-throughput sample presentation serial diffraction data collection at synchrotron X-ray free-electron laser (XFEL) sources. Truly loading chip (one...
Abstract X-ray free-electron lasers (XFELs) enable obtaining novel insights in structural biology. The recently available MHz repetition rate XFELs allow full data sets to be collected shorter time and can also decrease sample consumption. However, the microsecond spacing of XFEL pulses raises new challenges, including possible damage induced by shock waves that are launched preceding sample-carrying jet. We explored this matter with an X-ray-pump/X-ray-probe experiment employing haemoglobin...
Abstract Cry11Aa and Cry11Ba are the two most potent toxins produced by mosquitocidal Bacillus thuringiensis subsp. israelensis jegathesan , respectively. The naturally crystallize within host; however, crystals too small for structure determination at synchrotron sources. Therefore, we applied serial femtosecond crystallography X-ray free electron lasers to in vivo-grown nanocrystals of these toxins. was determined de novo using single-wavelength anomalous dispersion method, which turn...
Abstract Serial femtosecond crystallography at X-ray free-electron lasers (XFELs) offers unprecedented possibilities for macromolecular structure determination of systems prone to radiation damage. However, de novo determination, i.e., without prior structural knowledge, is complicated by the inherent inaccuracy serial data. By its very nature, data collection entails shot-to-shot fluctuations in wavelength and intensity as well variations crystal size quality that must be averaged out....
We present an experimental demonstration of the dynamics dual-wavelength emission from a coupled semiconductor microcavity laser after femtosecond optical excitation at 20 K. The is comprised two λ sized Al0.2Ga0.8As/Al0.5Ga0.5As cavities, separated by common mirror. bottom cavity contains three 10 nm thick GaAs quantum wells (QWs) whereas top 16 QWs. Time-resolved measurements stimulated show pulses as short 4.8 ps (10 ps) and peak delays 13 (16 for shorter (longer) wavelength. Fast pulse...
Abstract Reversibly photoswitchable fluorescent proteins are essential markers for advanced biological imaging, and optimization of their photophysical properties underlies improved performance novel applications. Here we establish a link between photoswitching contrast, one the key parameters that dictate achievable resolution in nanoscopy applications, chromophore conformation non‐fluorescent state rsEGFP2, widely employed label REversible Saturable OpticaL Fluorescence Transitions...
The semimagnetic semiconductors ${\mathrm{Cd}}_{1\mathrm{\ensuremath{-}}\mathit{x}\mathrm{\ensuremath{-}}\mathit{y}}$${\mathrm{Mn}}_{\mathit{x}}$${\mathrm{Mg}}_{\mathit{y}}$Te grown by molecular-beam epitaxy have been studied photoluminescence and excitation spectroscopy. It is shown that the Zeeman splittings of exciton states depend on Mn content only are independent Mg content, i.e., carrier--Mn spin-exchange constants not affected incorporation. Exciton magnetic polarons using method...
Shock waves launched by x-ray pulses in sample-carrying liquid jets may affect protein crystallography data collected at MHz repetition rate free-electron laser (XFEL) facilities, damaging the crystals before they are probed. We investigated shock damage lysozyme microcrystals using a double-pulse operation mode low facility. The generated with pressures that covered and exceeded expected pulse experiments European XFEL (EuXFEL) laser. quality of diffraction from was degraded after passed. A...
Summary High-intensity femtosecond pulses from an X-ray free-electron laser enable pump probe experiments for investigating electronic and nuclear changes during light-induced reactions. On time scales ranging femtoseconds to milliseconds a variety of biological systems, time-resolved serial crystallography (TR-SFX) has provided detailed structural data isomerization, breakage or formation chemical bonds electron transfer 1 . However, all ultra-fast TR-SFX studies date have employed such...
We study the emission dynamics of two In0.2Ga0.8As/GaAs microcavity lasers after femtosecond optical excitation at 20 K. The pulse widths and peak delays λ a 2λ cavity are compared. Pulses as short 3.3 ps (9.5 ps) 8.2 (16.5 obtained with (λ cavity). well described by model based on rate equation analysis for carrier photon densities; in particular, better high speed characteristics compared to reproduced.
We present a vertical-cavity surface-emitting laser structure optimized for fast intrinsic emission dynamics, using the strain-compensated (GaIn)As/Ga(PAs) material system with 2λ sin-type cavity. The high quality of epitaxial growth is revealed by large normal mode splitting 10.5 meV found in reflectivity measurements. dynamical response our after femtosecond optical excitation at 30 K yields pulse width 3.2 ps and peak delay only 4.8 ps. A designed higher temperatures exhibits picosecond...
Serial femtosecond crystallography (SFX) data were recorded at the European X-ray free-electron laser facility (EuXFEL) with protein microcrystals delivered via a microscopic liquid jet. An XFEL beam striking such jet may launch supersonic shock waves up jet, compromising oncoming sample. To investigate this efficiently, we employed novel pulse pattern to nominally expose sample between zero and four before being probed. Analyzing hit rate, indexing resolution for diffraction MHz rates,...
The influence of carrier relaxation on the emission dynamics a semiconductor microcavity laser is investigated using femtosecond optical excitation. For moderate excitation intensities, output pulse becomes significantly slower when photon energy pump tuned from quantum well band-gap towards higher energies. Theoretical calculations reproduce this trend only if interaction-induced dephasing polarization driven by pulse, formation, and nonequilibrium distribution as chirp are taken into...
We provide a detailed description of serial femtosecond crystallography (SFX) dataset collected at the European X-ray free-electron laser facility (EuXFEL). The EuXFEL is first high repetition rate XFEL delivering MHz pulse trains 10 Hz. short spacing (<1 µs) between pulses requires fast flowing microjets for sample injection and frame detectors. A data set was recorded microcrystalline mixture least three different jack bean proteins (urease, concanavalin A, B). one megapixel Adaptive Gain...
Abstract We provide a detailed description of gadoteridol-derivatized lysozyme (gadolinium lysozyme) two-colour serial femtosecond crystallography (SFX) dataset for multiple wavelength anomalous dispersion (MAD) structure determination. The data was collected at the Spring-8 Angstrom Compact free-electron LAser (SACLA) facility using double-pulse beam to record two diffraction patterns simultaneously in one image. Gadolinium chosen as well-established model system that has very strong...
Abstract Reversibly photoswitchable fluorescent proteins are essential markers for advanced biological imaging, and optimization of their photophysical properties underlies improved performance novel applications. Here we establish a link between photoswitching contrast, key parameter that largely dictates the achievable resolution in nanoscopy applications, chromophore conformation non-fluorescent state rsEGFP2, widely employed label REversible Saturable OpticaL Fluorescence Transitions...