scholarly journals Automated harvesting and processing of protein crystals through laser photoablation

2016 ◽  
Vol 72 (4) ◽  
pp. 454-466 ◽  
Author(s):  
Ulrich Zander ◽  
Guillaume Hoffmann ◽  
Irina Cornaciu ◽  
Jean-Pierre Marquette ◽  
Gergely Papp ◽  
...  

Currently, macromolecular crystallography projects often require the use of highly automated facilities for crystallization and X-ray data collection. However, crystal harvesting and processing largely depend on manual operations. Here, a series of new methods are presented based on the use of a low X-ray-background film as a crystallization support and a photoablation laser that enable the automation of major operations required for the preparation of crystals for X-ray diffraction experiments. In this approach, the controlled removal of the mother liquor before crystal mounting simplifies the cryocooling process, in many cases eliminating the use of cryoprotectant agents, while crystal-soaking experiments are performed through diffusion, precluding the need for repeated sample-recovery and transfer operations. Moreover, the high-precision laser enables new mounting strategies that are not accessible through other methods. This approach bridges an important gap in automation and can contribute to expanding the capabilities of modern macromolecular crystallography facilities.

2013 ◽  
Vol 46 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
Oliver B. Zeldin ◽  
Markus Gerstel ◽  
Elspeth F. Garman

RADDOSE-3D allows the macroscopic modelling of an X-ray diffraction experiment for the purpose of better predicting radiation-damage progression. The distribution of dose within the crystal volume is calculated for a number of iterations in small angular steps across one or more data collection wedges, providing a time-resolved picture of the dose state of the crystal. The code is highly modular so that future contributions from the community can be easily integrated into it, in particular to incorporate online methods for determining the shape of macromolecular crystals and better protocols for imaging real experimental X-ray beam profiles.


1999 ◽  
Vol 55 (10) ◽  
pp. 1718-1725 ◽  
Author(s):  
J. W. Pflugrath

X-ray diffraction images from two-dimensional position-sensitive detectors can be characterized as thick or thin, depending on whether the rotation-angle increment per image is greater than or less than the crystal mosaicity, respectively. The expectations and consequences of the processing of thick and thin images in terms of spatial overlap, saturated pixels, X-ray background andI/σ(I) are discussed. Thed*TREKsoftware suite for processing diffraction images is briefly introduced, and results fromd*TREKare compared with those from another popular package.


2014 ◽  
Vol 70 (a1) ◽  
pp. C351-C351
Author(s):  
Anna Warren ◽  
Wes Armour ◽  
Danny Axford ◽  
Mark Basham ◽  
Thomas Connolley ◽  
...  

The focus in macromolecular crystallography is moving towards even more challenging target proteins that often crystallise on much smaller scales and are frequently mounted in opaque or highly refractive materials.[1,2] It is therefore essential that X-ray beamline technology develops in parallel to accommodate such difficult samples. In this poster the use of X-ray microradiography and microtomography is reported as a tool for crystal visualisation, location and characterization on the macromolecular crystallography beamlines at the Diamond Light Source. The technique is particularly useful for microcrystals, and crystals mounted in opaque materials such as lipidic cubic phase. X-ray diffraction raster scanning can be used in combination with radiography to allow informed decision-making at the beamline prior to diffraction data collection. It is demonstrated that the X-ray dose required for a full tomography measurement is similar to a diffraction grid scan. However, for sample location and shape estimation alone, just a few radiographic projections may be required; hence reducing the dose the crystals will be exposed to prior to the diffraction data collection.[3]


2014 ◽  
Vol 70 (a1) ◽  
pp. C1735-C1735
Author(s):  
James Gorin ◽  
Shaunivan Labiuk ◽  
Julien Cotelesage ◽  
Kathryn Janzen ◽  
Michel Fodje ◽  
...  

The Canadian Macromolecular Crystallography Facility (CMCF) at the Canadian Light Source consists of two macromolecular crystallography beamlines for structure determination using x-ray diffraction. The equipment at the CMCF beamlines have undergone or will undergo changes and improvements to better meet the needs of the most challenging experiments users may present. Among these improvements are: 1) Automounter improvements; 2) Better goniometry on 08ID-1 with the addition of a Huber air-bearing goniometer; 3) Added beam size capabilities on 08ID-1 with the addition of a multiple beam defining aperture holder; 4) XAFS capability on 08B1-1; 5) Improved low energy S-SAD data collection with the addition of a Helium path; 6) Improvements to the data collection and data management software; 7) A vacuum path for scattering experiments with detector distances up to 1 m; 8) A comprehensive beamline upgrade project on the 08ID-1 beamline; and 9) Service crystallography services.


2013 ◽  
Vol 69 (7) ◽  
pp. 1252-1259 ◽  
Author(s):  
Anna J. Warren ◽  
Wes Armour ◽  
Danny Axford ◽  
Mark Basham ◽  
Thomas Connolley ◽  
...  

The focus in macromolecular crystallography is moving towards even more challenging target proteins that often crystallize on much smaller scales and are frequently mounted in opaque or highly refractive materials. It is therefore essential that X-ray beamline technology develops in parallel to accommodate such difficult samples. In this paper, the use of X-ray microradiography and microtomography is reported as a tool for crystal visualization, location and characterization on the macromolecular crystallography beamlines at the Diamond Light Source. The technique is particularly useful for microcrystals and for crystals mounted in opaque materials such as lipid cubic phase. X-ray diffraction raster scanning can be used in combination with radiography to allow informed decision-making at the beamline prior to diffraction data collection. It is demonstrated that the X-ray dose required for a full tomography measurement is similar to that for a diffraction grid-scan, but for sample location and shape estimation alone just a few radiographic projections may be required.


2015 ◽  
Vol 71 (10) ◽  
pp. 2079-2088 ◽  
Author(s):  
Anna J. Warren ◽  
Adam D. Crawshaw ◽  
Jose Trincao ◽  
Pierre Aller ◽  
Simon Alcock ◽  
...  

The measurement of diffraction data from macromolecular crystal samples heldin vacuoholds the promise of a very low X-ray background and zero absorption of incident and scattered beams, leading to better data and the potential for accessing very long X-ray wavelengths (>3 Å) for native sulfur phasing. Maintaining the hydration of protein crystals under vacuum is achieved by the use of liquid jets, as with serial data collection at free-electron lasers, or is side-stepped by cryocooling the samples, as implemented at new synchrotron beamlines. Graphene has been shown to protect crystals from dehydration by creating an extremely thin layer that is impermeable to any exchanges with the environment. Furthermore, owing to its hydrophobicity, most of the aqueous solution surrounding the crystal is excluded during sample preparation, thus eliminating most of the background caused by liquid. Here, it is shown that high-quality data can be recorded at room temperature from graphene-wrapped protein crystals in a rough vacuum. Furthermore, it was observed that graphene protects crystals exposed to different relative humidities and a chemically harsh environment.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1440-C1440 ◽  
Author(s):  
Luis Fuentes-Montero ◽  
James Parkhurst ◽  
Graeme Winter ◽  
David Waterman ◽  
Richard Gildea ◽  
...  

DIALS is a collaborative initiative to produce an open source software toolbox encompassing all aspects of diffraction data analysis, with an initial focus on X-ray diffraction data from synchrotrons and free-electron lasers for macromolecular crystallography. DIALS [1] has been developed as a modular plug-in framework that permits flexibility not only in the development of new methods and algorithms but also in the application of these methods to data analysis. DIALS builds on the cctbx [2] in addition to its own dedicated tool-kits. We will present the ideas behind DIALS and give examples of its versatility in permitting the use of several spot-finding and indexing schemes, global refinement and both two and three dimensional integration methods.


Crystals ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 273 ◽  
Author(s):  
José Brandão-Neto ◽  
Leonardo Bernasconi

Macromolecular crystallography at cryogenic temperatures has so far provided the majority of the experimental evidence that underpins the determination of the atomic structures of proteins and other biomolecular assemblies by means of single crystal X-ray diffraction experiments. One of the core limitations of the current methods is that crystal samples degrade as they are subject to X-rays, and two broad groups of effects are observed: global and specific damage. While the currently successful approach is to operate outside the range where global damage is observed, specific damage is not well understood and may lead to poor interpretation of the chemistry and biology of the system under study. In this work, we present a phenomenological model in which specific damage is understood as the result of a single process, the steady excitation of crystal electrons caused by X-ray absorption, which acts as a trigger for the bulk effects that manifest themselves in the form of global damage and obscure the interpretation of chemical information from XFEL and synchrotron structural research.


1982 ◽  
Vol 126 (3) ◽  
pp. 307-316 ◽  
Author(s):  
W. A. P. Nicholson ◽  
W. H. Biddlecombe ◽  
H. Y. Elder
Keyword(s):  
X Ray ◽  

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