scholarly journals ASAXS measurements on ferritin and apoferritin at the bioSAXS beamline P12 (PETRA III, DESY)

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
D. C. F. Wieland ◽  
M. A. Schroer ◽  
A. Yu. Gruzinov ◽  
C. E. Blanchet ◽  
C. M. Jeffries ◽  
...  
Keyword(s):  
Small Angle ◽  
Protein Solutions ◽  
Anomalous Scattering ◽  
Biological Macromolecules ◽  
X Ray ◽  
Protein Cages ◽  
Additional Information ◽  
X Ray Scattering ◽  
Structural Details ◽  
Ray Scattering

Small-angle X-ray scattering is widely utilized to study biological macromolecules in solution. For samples containing specific (e.g. metal) atoms, additional information can be obtained using anomalous scattering. Here, measuring samples at different energies close to the absorption edges of relevant elements provides specific structural details. However, anomalous small-angle X-ray scattering (ASAXS) applications to dilute macromolecular solutions are challenging owing to the overall low anomalous scattering effect. Here, pilot ASAXS experiments from dilute solutions of ferritin and cobalt-loaded apoferritin are reported. These samples were investigated near the resonance X-ray K edges of Fe and Co, respectively, at the EMBL P12 bioSAXS beamline at PETRA III, DESY. Thanks to the high brilliance of the P12 beamline, ASAXS experiments are feasible on dilute protein solutions, allowing one to extract the Fe- or Co-specific anomalous dispersion terms from the ASAXS data. The data were subsequently used to determine the spatial distribution of either iron or cobalt atoms incorporated into the ferritin/apoferritin protein cages.

scholarly journals Smaller capillaries improve the small-angle X-ray scattering signal and sample consumption for biomacromolecular solutions

2018 ◽  
Vol 25 (4) ◽  
pp. 1113-1122 ◽  
Author(s):  
Martin A. Schroer ◽  
Clement E. Blanchet ◽  
Andrey Yu. Gruzinov ◽  
Melissa A. Gräwert ◽  
Martha E. Brennich ◽  
...  
Keyword(s):  
Small Angle ◽  
A Priori ◽  
Protein Solutions ◽  
Biological Macromolecules ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
A Cell ◽  
Flow Through ◽  
Ray Scattering

Radiation damage by intense X-ray beams at modern synchrotron facilities is one of the major complications for biological small-angle X-ray scattering (SAXS) investigations of macromolecules in solution. To limit the damage, samples are typically measured under a laminar flow through a cell (typically a capillary) such that fresh solution is continuously exposed to the beam during measurement. The diameter of the capillary that optimizes the scattering-to-absorption ratio at a given X-ray wavelength can be calculated a priori based on fundamental physical properties. However, these well established scattering and absorption principles do not take into account the radiation susceptibility of the sample or the often very limited amounts of precious biological material available for an experiment. Here it is shown that, for biological solution SAXS, capillaries with smaller diameters than those calculated from simple scattering/absorption criteria allow for a better utilization of the available volumes of radiation-sensitive samples. This is demonstrated by comparing two capillary diameters d i (d i = 1.7 mm, close to optimal for 10 keV; and d i = 0.9 mm, which is nominally sub-optimal) applied to study different protein solutions at various flow rates. The use of the smaller capillaries ultimately allows one to collect higher-quality SAXS data from the limited amounts of purified biological macromolecules.

scholarly journals The new NCPSS BL19U2 beamline at the SSRF for small-angle X-ray scattering from biological macromolecules in solution

2016 ◽  
Vol 49 (5) ◽  
pp. 1428-1432 ◽  
Author(s):  
Na Li ◽  
Xiuhong Li ◽  
Yuzhu Wang ◽  
Guangfeng Liu ◽  
Ping Zhou ◽  
...  
Keyword(s):  
Data Processing ◽  
Small Angle ◽  
Dynamic Range ◽  
Silicon Crystal ◽  
High Dynamic Range ◽  
Biological Macromolecules ◽  
Shanghai Synchrotron Radiation Facility ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The beamline BL19U2 is located in the Shanghai Synchrotron Radiation Facility (SSRF) and is its first beamline dedicated to biological material small-angle X-ray scattering (BioSAXS). The electrons come from an undulator which can provide high brilliance for the BL19U2 end stations. A double flat silicon crystal (111) monochromator is used in BL19U2, with a tunable monochromatic photon energy ranging from 7 to 15 keV. To meet the rapidly growing demands of crystallographers, biochemists and structural biologists, the BioSAXS beamline allows manual and automatic sample loading/unloading. A Pilatus 1M detector (Dectris) is employed for data collection, characterized by a high dynamic range and a short readout time. The highly automated data processing pipeline SASFLOW was integrated into BL19U2, with help from the BioSAXS group of the European Molecular Biology Laboratory (EMBL, Hamburg), which provides a user-friendly interface for data processing. The BL19U2 beamline was officially opened to users in March 2015. To date, feedback from users has been positive and the number of experimental proposals at BL19U2 is increasing. A description of the new BioSAXS beamline and the setup characteristics is given, together with examples of data obtained.

Quality control of protein standards for molecular mass determinations by small-angle X-ray scattering

2010 ◽  
Vol 43 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Shuji Akiyama
Keyword(s):  
Quality Control ◽  
Molecular Mass ◽  
Small Angle ◽  
Biological Macromolecules ◽  
Average Deviation ◽  
Saxs Data ◽  
X Ray ◽  
X Ray Scattering ◽  
Standard Quality ◽  
Ray Scattering

Small-angle X-ray scattering (SAXS) is a powerful technique with which to evaluate the size and shape of biological macromolecules in solution. Forward scattering intensity normalized relative to the particle concentration,I(0)/c, is useful as a good measure of molecular mass. A general method for deducing the molecular mass from SAXS data is to determine the ratio ofI(0)/cof a target protein to that of a standard protein with known molecular mass. The accuracy of this interprotein calibration is affected considerably by the monodispersity of the prepared standard, as well as by the precision in estimating its concentration. In the present study, chromatographic fractionation followed by hydrodynamic characterization is proposed as an effective procedure by which to prepare a series of monodispersed protein standards. The estimation of molecular mass within an average deviation of 8% is demonstrated using monodispersed bovine serum albumin as a standard. The present results demonstrate the importance of protein standard quality control in order to take full advantage of interprotein calibration.

Recent developments in small-angle X-ray scattering and hybrid method approaches for biomacromolecular solutions

2018 ◽  
Vol 2 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Martin A. Schroer ◽  
Dmitri I. Svergun
Keyword(s):  
Small Angle ◽  
Scattering Data ◽  
Quality Data ◽  
Biological Macromolecules ◽  
Ambient Conditions ◽  
X Ray ◽  
X Ray Scattering ◽  
Analysis Methods ◽  
Recent Developments ◽  
Ray Scattering

Small-angle X-ray scattering (SAXS) has become a streamline method to characterize biological macromolecules, from small peptides to supramolecular complexes, in near-native solutions. Modern SAXS requires limited amounts of purified material, without the need for labelling, crystallization, or freezing. Dedicated beamlines at modern synchrotron sources yield high-quality data within or below several milliseconds of exposure time and are highly automated, allowing for rapid structural screening under different solutions and ambient conditions but also for time-resolved studies of biological processes. The advanced data analysis methods allow one to meaningfully interpret the scattering data from monodisperse systems, from transient complexes as well as flexible and heterogeneous systems in terms of structural models. Especially powerful are hybrid approaches utilizing SAXS with high-resolution structural techniques, but also with biochemical, biophysical, and computational methods. Here, we review the recent developments in the experimental SAXS practice and in analysis methods with a specific focus on the joint use of SAXS with complementary methods.

Small-angle energy-dispersive X-ray scattering using a laboratory-based diffractometer with a conventional source

2007 ◽  
Vol 40 (2) ◽  
pp. 218-231 ◽  
Author(s):  
Giuseppe Portale ◽  
Alessandro Longo ◽  
Lucio D'Ilario ◽  
Andrea Martinelli ◽  
Ruggero Caminiti ◽  
...  
Keyword(s):  
Small Angle ◽  
Energy Dispersive ◽  
Protein Solutions ◽  
X Rays ◽  
Catalytic Systems ◽  
X Ray ◽  
X Ray Scattering ◽  
Angle Scattering ◽  
Ray Patterns ◽  
Ray Scattering

The use of polychromaticBremsstrahlungX-rays generated by commercial tubes for energy-dispersive small-angle scattering measurements has not been extensively discussed in the literature, mainly because of some difficulties associated with it. If a suitable experimental setup is chosen and concomitant phenomena are taken into account for correcting the observed X-ray patterns, energy-dispersive small-angle X-ray scattering (SAXS) may become an interesting alternative to conventional measurements based on monochromatic beams. Energy-dispersive SAXS experiments carried out on protein solutions, micelles, semicrystalline polymers and catalytic systems are discussed to illustrate the new opportunities offered by this technique as well as its limitations.

Sign in / Sign up

Export Citation Format

Share Document