A5087098226- Enzyme Structure and Function
- Advanced X-ray Imaging Techniques
- Advanced Electron Microscopy Techniques and Applications
- Biochemical and Molecular Research
- Photosynthetic Processes and Mechanisms
- Protein Structure and Dynamics
- Light effects on plants
- Advanced Memory and Neural Computing
- Transition Metal Oxide Nanomaterials
- Biocrusts and Microbial Ecology
- High-pressure geophysics and materials
- Crystallography and Radiation Phenomena
- Computational Drug Discovery Methods
- Semiconductor materials and devices
- Force Microscopy Techniques and Applications
- Phase-change materials and chalcogenides
- Porphyrin Metabolism and Disorders
- Thermal properties of materials
- Digital Holography and Microscopy
- Image and Signal Denoising Methods
- Neural dynamics and brain function
- X-ray Spectroscopy and Fluorescence Analysis
- Diffusion Coefficients in Liquids
- Antibiotic Resistance in Bacteria
- Physics of Superconductivity and Magnetism
Argonne National Laboratory
2023-2024
University of Wisconsin–Milwaukee
2016-2023
Tribhuvan University
2014
Ever since the first atomic structure of an enzyme was solved, discovery mechanism and dynamics reactions catalyzed by biomolecules has been key goal for understanding molecular processes that drive life on earth. Despite a large number successful methods trapping reaction intermediates, direct observation ongoing possible only in rare exceptional cases.
Mix-and-inject serial crystallography (MISC) is a technique designed to image enzyme catalyzed reactions in which small protein crystals are mixed with substrate just prior being probed by an X-ray pulse. This approach offers several advantages over flow cell studies. It provides (i) room temperature structures at near atomic resolution, (ii) time resolution ranging from microseconds seconds, and (iii) convenient reaction initiation. outruns radiation damage using femtosecond pulses allowing...
Here, we illustrate what happens inside the catalytic cleft of an enzyme when substrate or ligand binds on single-millisecond timescales. The initial phase enzymatic cycle is observed with near-atomic resolution using most advanced X-ray source currently available: European XFEL (EuXFEL). high repetition rate EuXFEL combined our mix-and-inject technology enables ceftriaxone binding to
Abstract For decades, researchers have elucidated essential enzymatic functions on the atomic length scale by tracing positions in real-time. Our work builds possibilities unleashed mix-and-inject serial crystallography (MISC) at X-ray free electron laser facilities. In this approach, reactions are triggered mixing substrate or ligand solutions with enzyme microcrystals. Here, we report detail (between 2.2 and 2.7 Å resolution) room-temperature, time-resolved millisecond time-resolution...
Abstract Phytochromes are a family of photoreceptors that control light responses plants, fungi and bacteria. A sequence structural changes, which is not yet fully understood, leads to activation an output domain. Time-resolved serial femtosecond crystallography (SFX) can potentially shine on these conformational changes. Here we report the room temperature crystal structure chromophore-binding domains Deinococcus radiodurans phytochrome at 2.1 Å resolution. The was obtained by X-ray from...
Phytochromes are red-light photoreceptors that were first characterized in plants, with homologs photosynthetic and non-photosynthetic bacteria known as bacteriophytochromes (BphPs). Upon absorption of light, BphPs interconvert between two states denoted Pr Pfr distinct spectra the red far-red. They have recently been engineered enzymatic photoswitches for fluorescent-marker applications non-invasive tissue imaging mammals. This article presents cryo- room-temperature crystal structures...
X-ray free-electron lasers (XFELs) open the possibility of obtaining diffraction information from a single biological macromolecule. This is because XFELs can generate extremely intense x-ray pulses that are so short data be collected before sample destroyed. By collecting sufficient number single-particle patterns, three-dimensional electron density molecule reconstructed ab initio. The quality reconstruction depends largely on patterns at experiment. paper provides an estimate required to...
Electrical triggering of a metal–insulator transition (MIT) often results in the formation characteristic spatial patterns such as metallic filament percolating through an insulating matrix or barrier splitting conducting matrix. When MIT is driven by electrothermal effects, temperature can be substantially higher than rest material. Using X-ray microdiffraction and dark-field microscopy, we show that leads to development inhomogeneous strain profile across switching device, even when...
With time-resolved crystallography (TRX), it is possible to follow the reaction dynamics in biological macromolecules by investigating structure of transient states along coordinate. X-ray free electron lasers (XFELs) have enabled TRX experiments on previously uncharted femtosecond timescales. Here, we review recent developments, opportunities, and challenges pump-probe at XFELs.
Recent developments in X-ray science provide methods to probe deeply embedded mesoscale grain structures and spatially resolve them using dark field microscopy (DFXM). Extending this technique investigate weak diffraction signals such as magnetic systems, quantum materials thin films prove challenging due available detection incident flux at the sample. We present a direct method developed conjunction with KAImaging which focuses on DFXM studies hard range of 10s keV above capable...
Abstract In this paper we demonstrated a method to reconstruct vector-valued lattice distortion fields within nanoscale crystals by optimization of forward model multi-reflection Bragg coherent diffraction imaging (MR-BCDI) data. The flexibly accounts for geometric factors that arise when making BCDI measurements, is amenable efficient inversion with modern toolkits, and allows globally constraining single image reconstruction multiple peak measurements. This enabled emulates the peaks...
Abstract There is an urgent need for anti-viral agents that treat and/or prevent Covid-19 caused by SARS-Coronavirus (CoV-2) infections. The replication of the SARS CoV-2 dependent on activity two cysteine proteases, a papain-like protease, PL-pro, and 3C-like protease known as main Mpro or 3CLpro. shortest safest path to clinical use repurposing drugs with binding affinity PLpro 3CLpro have established safety profile in humans. Several studies reported crystal structures SARS-CoV-2 complex...
<title>Abstract</title> Neuromorphic functions in memristive devices, linked to electrically induced resistive switching form conductive pathways, could be made more efficient by insights into filament formation at micro- and mesoscopic levels. Despite extensive research on VO<sub>2</sub>, a key material for its formation, local <italic>operando</italic> structural measurements are highly challenging often involve destructive specimen preparation long rastering time, which greatly limits the...
For decades, researchers have been determined to elucidate essential enzymatic functions on the atomic lengths scale by tracing positions in real time. Our work builds new possibilities unleashed mix-and-inject serial crystallography (MISC) 1-5 at X-ray free electron laser facilities. In this approach, reactions are triggered mixing substrate or ligand solutions with enzyme microcrystals 6 . Here, we report detail and millisecond time-resolution how Mycobacterium tuberculosis BlaC is...
Electrical triggering of a metal-insulator transition (MIT) often results in the formation characteristic spatial patterns such as metallic filament percolating through an insulating matrix or barrier splitting conducting matrix. When MIT is driven by electrothermal effects, temperature can be substantially higher than rest material. Using x-ray microdiffraction and dark-field microscopy, we show that leads to development inhomogeneous strain profile across switching device, even when...
Neuromorphic functionalities in memristive devices are commonly associated with the ability to electrically create local conductive pathways by resistive switching. The archetypal correlated material, VO2, has been intensively studied for its complex electronic and structural phase transition as well filament formation under applied voltages. Local studies of behavior often limited due time-consuming rastering which makes impractical many experiments aimed at investigating large spatial...
Abstract The SARS coronavirus 2 main protease 3CLpro tailor cuts various essential virus proteins out of long poly-protein translated from the RNA. If is inhibited, functional cannot form and replicate assemble. Any compound that inhibits therefore a potential drug to end pandemic. Here we show diffraction power crystals effectively destroyed by Ebselen. It appears Ebselen may be widely available, relatively cost effective way eliminate 2.
Ever since the first atomic structure of an enzyme was solved, discovery mechanism and dynamics reactions catalyzed by biomolecules has been key goal for understanding molecular processes that drive life on earth. Despite a large number successful methods trapping reaction intermediates, direct observation ongoing possible only in rare exceptional cases. Here, we demonstrate general method capturing catalysis ‘in-action’ ‘mix-and-inject serial crystallography’. Specifically, follow catalytic...
Abstract Phytochromes are red/far-red light photoreceptors in bacteria to plants, which elicit a variety of important physiological responses. They display reversible photocycle between the resting (dark) Pr state and activated Pfr state, signals received transduced as structural change through entire protein modulate activity protein. It is unknown how Pr-to-Pfr interconversion occurs structure intermediates remain notoriously elusive. Here, we present short-lived crystal structures...
Abstract In this study, we follow the diffusion and buildup of occupancy substrate ceftriaxone in M. tuberculosis β-lactamase BlaC microcrystals by structural analysis enzyme complex at single millisecond time resolution. We also show binding reaction an inhibitor, sulbactam, on a slower scale. use ‘mix-and-inject’ technique to initiate these reactions diffusion, determine resulting structures serial crystallography using ultrafast, intense X-ray pulses from European XFEL (EuXFEL) arriving...