Baden, Switzerland


Baden, Switzerland
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Forster A.,Macromolecular Crystallography | Schulze-Briese C.,DECTRIS Ltd.
Industrial Pharmacy | Year: 2015

Rational drug design depends on structural information of the biological target to model ligands and optimise interactions. Recent advances in detector design, exemplified by the EIGER family of X-ray detectors, have dramatically improved the quality of data that can be obtained from protein crystals. © 2015 Euromed Communications.

Chiu E.,University of Auckland | Hijnen M.,Monash University | Hijnen M.,General Electric | Bunker R.D.,Friedrich Miescher Institute for Biomedical Research | And 13 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015

The great benefits that chemical pesticides have brought to agriculture are partly offset by widespread environmental damage to nontarget species and threats to human health. Microbial bioinsecticides are considered safe and highly specific alternatives but generally lack potency. Spindles produced by insect poxviruses are crystals of the fusolin protein that considerably boost not only the virulence of these viruses but also, in cofeeding experiments, the insecticidal activity of unrelated pathogens. However, the mechanisms by which spindles assemble into ultra-stable crystals and enhance virulence are unknown. Here we describe the structure of viral spindles determined by X-ray microcrystallography from in vivo crystals purified from infected insects. We found that a C-terminal molecular arm of fusolin mediates the assembly of a globular domain, which has the hallmarks of lytic polysaccharide monooxygenases of chitinovorous bacteria. Explaining their unique stability, a 3D network of disulfide bonds between fusolin dimers covalently crosslinks the entire crystalline matrix of spindles. However, upon ingestion by a new host, removal of the molecular arm abolishes this stabilizing network leading to the dissolution of spindles. The released monooxygenase domain is then free to disrupt the chitinrich peritrophic matrix that protects insects against oral infections. The mode of action revealed here may guide the design of potent spindles as synergetic additives to bioinsecticides.

Rutishauser S.,Paul Scherrer Institute | Zanette I.,European Synchrotron Radiation Facility | Weitkamp T.,Synchrotron Soleil | Donath T.,Paul Scherrer Institute | And 2 more authors.
Applied Physics Letters | Year: 2011

We report on the application of a two-dimensional hard x-ray grating interferometer to x-ray optics metrology. The interferometer is sensitive to refraction angles in two perpendicular directions with a precision of 10 nrad. It is used to observe the wavefront changes induced by a single parabolic beryllium focusing lens of large radius of curvature. The lens shape is reconstructed and its residual aberrations are analyzed. Its profile differs from an ideal parabolic shape by less than 2 m or /50 at 0.54 wavelength. © 2011 American Institute of Physics.

Waltersperger S.,Paul Scherrer Institute | Olieric V.,Paul Scherrer Institute | Pradervand C.,Paul Scherrer Institute | Glettig W.,Center Suisse dElectronique et Microtechnique | And 9 more authors.
Journal of Synchrotron Radiation | Year: 2015

The Parallel Robotics Inspired Goniometer (PRIGo) is a novel compact and high-precision goniometer providing an alternative to (mini-)kappa, traditional three-circle goniometers and Eulerian cradles used for sample reorientation in macromolecular crystallography. Based on a combination of serial and parallel kinematics, PRIGo emulates an arc. It is mounted on an air-bearing stage for rotation around ω and consists of four linear positioners working synchronously to achieve x, y, z translations and χ rotation (0-90°), followed by a φ stage (0-360°) for rotation around the sample holder axis. Owing to the use of piezo linear positioners and active correction, PRIGo features spheres of confusion of <1 μm, <7 μm and <10 μm for ω, χ and φ, respectively, and is therefore very well suited for micro-crystallography. PRIGo enables optimal strategies for both native and experimental phasing crystallographic data collection. Herein, PRIGo hardware and software, its calibration, as well as applications in macromolecular crystallography are described. © 2015 International Union of Crystallography.

Rajendran C.,Paul Scherrer Institute | Dworkowski F.S.N.,Paul Scherrer Institute | Wang M.,Paul Scherrer Institute | Schulze-Briese C.,Paul Scherrer Institute | Schulze-Briese C.,Dectris Ltd
Journal of Synchrotron Radiation | Year: 2011

The first study of room-temperature macromolecular crystallography data acquisition with a silicon pixel detector is presented, where the data are collected in continuous sample rotation mode, with millisecond read-out time and no read-out noise. Several successive datasets were collected sequentially from single test crystals of thaumatin and insulin. The dose rate ranged between ∼1320 Gy s-1 and ∼8420 Gy s-1 with corresponding frame rates between 1.565 Hz and 12.5 Hz. The data were analysed for global radiation damage. A previously unreported negative dose-rate effect is observed in the indicators of global radiation damage, which showed an approximately 75% decrease in D1/2 at sixfold higher dose rate. The integrated intensity decreases in an exponential manner. Sample heating that could give rise to the enhanced radiation sensitivity at higher dose rate is investigated by collecting data between crystal temperatures of 298 K and 353 K. UV-Vis spectroscopy is used to demonstrate that disulfide radicals and trapped electrons do not accumulate at high dose rates in continuous data collection. © 2011 International Union of Crystallography Printed in Singapore - all rights reserved.

Wright G.S.A.,Institute of Integrative Biology | Lee H.C.,Institute of Integrative Biology | Schulze-Briese C.,Dectris Ltd | Grossmann J.G.,Institute of Integrative Biology | And 2 more authors.
Journal of Synchrotron Radiation | Year: 2013

This study analyses the potential for laboratory-based size-exclusion chromatography (SEC) integrated small-angle X-ray scattering (SAXS) instrumentation to characterize protein complexes. Using a high-brilliance home source in conjunction with a hybrid pixel X-ray detector, the efficacy of SAXS data collection at pertinent protein concentrations and exposure times has been assessed. Scattering data from SOD1 and from the complex of SOD1 with its copper chaperone, using 10 min exposures, provided data quality in the range 0.03 < q < 0.25 Å-1 that was sufficient to accurately assign radius of gyration, maximum dimension and molecular mass. These data demonstrate that a home source with integrated SEC-SAXS technology is feasible and would enable structural biologists studying systems containing transient protein complexes, or proteins prone to aggregation, to make advanced preparations in-house for more effective use of limited synchrotron beam time. © 2013 International Union of Crystallography.

Pompidor G.,Paul Scherrer Institute | Dworkowski F.S.N.,Paul Scherrer Institute | Thominet V.,Paul Scherrer Institute | Schulze-Briese C.,DECTRIS Ltd. | Fuchs M.R.,Paul Scherrer Institute
Journal of Synchrotron Radiation | Year: 2013

The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years. © 2013 International Union of Crystallography Printed in Singapore-all rights reserved.

Owen R.L.,Diamond Light Source | Paterson N.,Diamond Light Source | Axford D.,Diamond Light Source | Aishima J.,Diamond Light Source | And 6 more authors.
Acta Crystallographica Section D: Biological Crystallography | Year: 2014

A departure from a linear or an exponential intensity decay in the diffracting power of protein crystals as a function of absorbed dose is reported. The observation of a lag phase raises the possibility of collecting significantly more data from crystals held at room temperature before an intolerable intensity decay is reached. A simple model accounting for the form of the intensity decay is reintroduced and is applied for the first time to high frame-rate room-temperature data collection. © 2014 International Union of Crystallography.

Trueb P.,DECTRIS Ltd | Sobott B.A.,University of Melbourne | Schnyder R.,DECTRIS Ltd | Loeliger T.,DECTRIS Ltd | And 5 more authors.
Journal of Synchrotron Radiation | Year: 2012

The PILATUS detector system is widely used for X-ray experiments at third-generation synchrotrons. It is based on a hybrid technology combining a pixelated silicon sensor with a CMOS readout chip. Its single-photon-counting capability ensures precise and noise-free measurements. The counting mechanism introduces a short dead-time after each hit, which becomes significant for rates above 10 6 photons s -1 pixel -1. The resulting loss in the number of counted photons is corrected for by applying corresponding rate correction factors. This article presents the results of a Monte Carlo simulation which computes the correction factors taking into account the detector settings as well as the time structure of the X-ray beam at the synchrotron. The results of the simulation show good agreement with experimentally determined correction factors for various detector settings at different synchrotrons. The application of accurate rate correction factors improves the X-ray data quality acquired at high photon fluxes. Furthermore, it is shown that the use of fast detector settings in combination with an optimized time structure of the X-ray beam allows for measurements up to rates of 10 7 photons s -1 pixel -1. © 2012 International Union of Crystallography.

Donath T.,DECTRIS Ltd. | Rissi M.,DECTRIS Ltd. | Billich H.,Paul Scherrer Institute
Synchrotron Radiation News | Year: 2013

A two-day workshop on beamline integration and data formatting (HDF5/NeXus) of the EIGER detector was held in Baden, Switzerland, January 24-25, 2013. Its aim was to discuss the technical challenges inherent with the next generation of high-frame-rate, high-resolution X-ray imaging detectors, and specifically with the EIGER detector. EIGER is a photon-counting hybrid pixel detector developed at the Paul Scherrer Institute (PSI) and DECTRIS Ltd. With even higher spatial resolution and frame rates than its predecessor, the PILATUS detector, it will be able to continuously produce up to 3000 images per second. The corresponding extreme data rates generated by this and future detectors present a significant challenge for beamline integration of the detectors, for data handling by the users, and for data processing software. Efficient data flow, storage, and processing must be achieved to handle the huge data sets that will be produced in seconds by these devices. © 2013 Copyright Taylor and Francis Group, LLC.

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