scholarly journals Evaluation of crystal quality of thin protein crystals based on the dynamical theory of X-ray diffraction

IUCrJ ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 761-766
Author(s):  
Marina Abe ◽  
Ryo Suzuki ◽  
Kenichi Kojima ◽  
Masaru Tachibana
Keyword(s):  
Imaging Techniques ◽  
Glucose Isomerase ◽  
Dynamical Theory ◽  
Protein Crystals ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Dynamical Diffraction ◽  
X Ray ◽  
Equal Thickness

Knowledge of X-ray diffraction in macromolecular crystals is important for not only structural analysis of proteins but also diffraction physics. Dynamical diffraction provides evidence of perfect crystals. Until now, clear dynamical diffraction in protein crystals has only been observed in glucose isomerase crystals. We wondered whether there were other protein crystals with high quality that exhibit dynamical diffraction. Here we report the observation of dynamical diffraction in thin ferritin crystals by rocking-curve measurement and imaging techniques such as X-ray topography. It is generally known that in the case of thin crystals it is difficult to distinguish whether dynamical diffraction occurs from only rocking-curve profiles. Therefore, our results clarified that dynamical diffraction occurs in thin protein crystals because fringe contrasts similar to Pendellösung fringes were clearly observed in the X-ray topographic images. For macromolecular crystallography, it is hard to obtain large crystals because they are difficult to crystallize. For thin crystals, dynamical diffraction can be demonstrated by analysis of the equal-thickness fringes observed by X-ray topography.

scholarly journals Analysis of oscillatory rocking curve by dynamical diffraction in protein crystals

2018 ◽  
Vol 115 (14) ◽  
pp. 3634-3639 ◽  
Author(s):  
Ryo Suzuki ◽  
Haruhiko Koizumi ◽  
Keiichi Hirano ◽  
Takashi Kumasaka ◽  
Kenichi Kojima ◽  
...  
Keyword(s):  
Glucose Isomerase ◽  
Dynamical Theory ◽  
Protein Crystals ◽  
X Ray Diffraction ◽  
High Quality ◽  
Rocking Curve ◽  
Dynamical Diffraction ◽  
High Quality Protein ◽  
Good Agreement

High-quality protein crystals meant for structural analysis by X-ray diffraction have been grown by various methods. The observation of dynamical diffraction in protein crystals is an interesting topic because dynamical diffraction generally occurs in perfect crystals such as Si crystals. However, to our knowledge, there is no report yet on protein crystals showing clear dynamical diffraction. We wonder whether the perfection of protein crystals might still be low compared with that of high-quality Si crystals. Here, we present observations of the oscillatory profile of rocking curves for protein crystals such as glucose isomerase crystals. The oscillatory profiles are in good agreement with those predicted by the dynamical theory of diffraction. We demonstrate that dynamical diffraction occurs even in protein crystals. This suggests the possibility of the use of dynamical diffraction for the determination of the structure and charge density of proteins.

Control of strain in subgrains of protein crystals by the introduction of grown-in dislocations

2021 ◽  
Vol 77 (5) ◽  
pp. 599-605
Author(s):  
Haruhiko Koizumi ◽  
Satoshi Uda ◽  
Ryo Suzuki ◽  
Masaru Tachibana ◽  
Kenichi Kojima ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Local Strain ◽  
Glucose Isomerase ◽  
Crystal Quality ◽  
Protein Crystals ◽  
Data Sets ◽  
X Ray Diffraction ◽  
X Ray ◽  
Equal Thickness

It is important to reveal the exact cause of poor diffractivity in protein crystals in order to determine the accurate structure of protein molecules. It is shown that there is a large amount of local strain in subgrains of glucose isomerase crystals even though the overall crystal quality is rather high, as shown by clear equal-thickness fringes in X-ray topography. Thus, a large stress is exerted on the subgrains of protein crystals, which could significantly lower the resistance of the crystals to radiation damage. It is also demonstrated that this local strain can be reduced through the introduction of dislocations in the crystal. This suggests that the introduction of dislocations in protein crystals can be effective in enhancing the crystal quality of subgrains of protein crystals. By exploiting this effect, the radiation damage in subgrains could be decreased, leading to the collection of X-ray diffraction data sets with high diffractivity.

CdTe Films Grown on InSb Substrates by Organometallic Epitaxy

1986 ◽  
Vol 90 ◽  
Author(s):  
I. B. Bhat ◽  
N. R. Taskar ◽  
J. Ayers ◽  
K. Patel ◽  
S. K. Ghandhi
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Organometallic Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Rocking Curve ◽  
X Ray ◽  
Cdte Films ◽  
Secondary Ion ◽  
Cdte Growth

ABSTRACTCadmium telluride layers were grown on InSb substrates by organometallic vapor phase epitaxy and examined using secondary ion mass spectrometry (SIMS), photoluminescence (Pb) and double crystal x-ray diffraction (DCD). The substrate temperature and the nature of the surface prior to growth are shown to be the most important parameters which influence the quality of CdTe layers. Growth on diethyltelluride (DETe) stabilized InSb substrates resulted in CdTe growth with a misorientation of about 4 minutes of arc with respect to the substrates. On the other hand, the grown layers followed the orientation of the substrates when a dimethylcadmium (DMCd) stabilized InSb was used. Growth at 350°C resulted in the smallest x-ray rocking curve (DCRC) full width at half maximum (FWHM) of about 20 arc seconds.

scholarly journals Comparison of the Quality of Protein Crystals Grown by CLPC Seeds Method

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 501 ◽  
Author(s):  
Li ◽  
Yan ◽  
Liu ◽  
Wu ◽  
Liu ◽  
...  
Keyword(s):  
Diffraction Data ◽  
Protein Crystal ◽  
Protein Crystals ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
High Quality Protein

We present a systematic quality comparison of protein crystals obtained with and without cross-linked protein crystal (CLPC) seeds. Four proteins were used to conduct the experiments, and the results showed that crystals obtained in the presence of CLPC seeds exhibited a better morphology. In addition, the X-ray diffraction data showed that the CLPC seeds method is a powerful tool to obtain high-quality protein crystals. Therefore, we recommend the use of CLPC seeds in preparing high-quality diffracting protein crystals.

{224} Plane X-Ray Diffraction Study of GaAs on Si Wafers Using a Conventional Double Crystal Diffractometer

1987 ◽  
Vol 91 ◽  
Author(s):  
J.W. Lee ◽  
D.K. Bowen ◽  
J.P. Salerno
Keyword(s):  
Incident Angle ◽  
Wafer Surface ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Near Surface ◽  
Rocking Curve ◽  
X Ray ◽  
Gaas On Si ◽  
Plane Diffraction

ABSTRACTIn an effort to evaluate the near surface crystal quality of GaAs on Si wafers, {224} plane diffraction were investigated using a conventional double crystal x-ray diffractometer without any high intensity radiation source. The x-ray incident angle to wafer surface varied from 3.6 to 9.6 degrees for different {224} planes due to the substrate tilt angle of 3 degrees. The GaAs to Si rocking curve intensity ratio increased significantly as the incident angle decreased. For the diffraction with 3.6 degree incident angle, only the GaAs peak was detected from the 3.5 um thick GaAs on Si wafer and the GaAs peak became narrower. These indicates that this conventional x-ray diffraction technique is applicable for the near surface quality evaluation of GaAs on Si wafers.

Non-contact Current Transfer Induces the Formation and Improves the X-ray Diffraction Quality of Protein Crystals

2014 ◽  
Vol 14 (9) ◽  
pp. 4347-4354 ◽  
Author(s):  
Ilias Boltsis ◽  
George Lagoumintzis ◽  
Demetra S.M. Chatzileontiadou ◽  
Petros Giastas ◽  
Socrates J. Tzartos ◽  
...  
Keyword(s):  
Protein Crystals ◽  
Current Transfer ◽  
X Ray Diffraction ◽  
X Ray

Studies of Crystalunity for Sputter Deposited Bi-Based Oxide Films

1992 ◽  
Vol 275 ◽  
Author(s):  
Koichi Mizuno ◽  
Yo Ichikawa ◽  
Kentaro Setsune
Keyword(s):  
Thin Films ◽  
Oxide Films ◽  
Full Width ◽  
Half Maximum ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Ion Channeling ◽  
Sputter Deposited

ABSTRACTCrystalline quality of Bi-based oxide films has been evaluated by means of X-ray diffraction (XRD) and ion-channeling on the Rutherford backscattering (RBS). The films were sputter deposited 2201-phase Bi2Sr2Cu1O8-δ (BSCO) and 2212-phase Bi2Sr2Ca1Cu2O8-δ (BSCCO). They were prepared on MgO(100) and SrTiO3(100) substrates at the low temperature of 650°C during the deposition. The best quality, however thin films had poor crystallinity compared to single crystals, was obtained with the 2201-phase BSCO film that was deposited on a SrTiO3(100) substrate. The full width at half maximum (FWHM) value of the rocking curve on XRD for the film was estimated as 1560 (arc sec).

High Epitaxial Growth Rate of 4H-SiC Using Horizontal Hot-Wall CVD

2006 ◽  
Vol 527-529 ◽  
pp. 187-190 ◽  
Author(s):  
Rachael L. Myers-Ward ◽  
Y. Shishkin ◽  
Olof Kordina ◽  
I. Haselbarth ◽  
Stephen E. Saddow
Keyword(s):  
Growth Rate ◽  
Epitaxial Growth ◽  
Growth Process ◽  
Structural Quality ◽  
Growth Time ◽  
Film Morphology ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray

A 4H-SiC epitaxial growth process has been developed in a horizontal hot-wall CVD reactor using a standard chemistry of silane-propane-hydrogen, producing repeatable growth rates up to 32 μm/h. The growth rate was studied as a function of pressure, silane flow rate, and growth time. The structural quality of the films was determined by X-ray diffraction. A 65 μm thick epitaxial layer was grown at the 32 μm/h rate, resulting in a smooth, specular film morphology with occasional carrot-like and triangular defects. The film proved to be of high structural quality with an X-ray rocking curve FWHM value of the (0004) peak of 11 arcseconds.

Exotic X-ray back-diffraction: a path toward a soft inelastic X-ray scattering spectrometer

2014 ◽  
Vol 47 (5) ◽  
pp. 1658-1665 ◽  
Author(s):  
Marcelo Goncalves Hönnicke ◽  
Raymond Conley ◽  
Cesar Cusatis ◽  
Edson Massayuki Kakuno ◽  
Juan Zhou ◽  
...  
Keyword(s):  
Dynamical Theory ◽  
Extreme Condition ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
X Ray ◽  
Magnetic Imaging ◽  
X Ray Scattering ◽  
Low Energies ◽  
Different Temperatures ◽  
Ray Scattering

In this work, soft X-ray back-diffraction (XBD; X-ray diffraction at angles near and exactly equal to 90°) is explored. The experiment was conducted at the SXS beamline at Laboratorio Nacional de Luz Sincrotron, Brazil, at ∼3.2 keV. A high-resolution Si(220) multi-bounce back-diffraction monochromator was designed and constructed for this experiment. An ultra-thin Si(220) crystal (5 µm thick) was used as the sample. This ultra-thin crystal was characterized by profilometry, rocking-curve measurements and X-ray topography prior to the XBD measurements. It is shown that the measured forward-diffracted beam (o-beam) profiles, taken at different temperatures, are in close agreement with profiles predicted by the extended dynamical theory of X-ray diffraction, with the absence of multiple-beam diffraction (MBD). This is an important result for future studies on the basic properties of back-diffracted X-ray beams at energies slightly above the exact XBD condition (extreme condition where XBD is almost extinguished). Also, the results presented here indicate that stressed crystals behave like ideal strain-free crystals when used for low-energy XBD. This is mainly due to the large widths of XBD profiles, which lead to a low strain sensitivity in the detection of defects. This result opens up new possibilities for mounting spherical analyzers without degrading the energy resolution, at least for low energies. This is a path that may be used to construct a soft inelastic X-ray scattering spectrometer where different applications such as element-specific magnetic imaging tools could be explored.

scholarly journals A generic protocol for protein crystal dehydration using the HC1b humidity controller

2016 ◽  
Vol 72 (5) ◽  
pp. 629-640 ◽  
Author(s):  
Carina M. C. Lobley ◽  
James Sandy ◽  
Juan Sanchez-Weatherby ◽  
Marco Mazzorana ◽  
Tobias Krojer ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Relative Humidity ◽  
Glucose Isomerase ◽  
Protein Crystal ◽  
X Ray Diffraction ◽  
Extended Study ◽  
X Ray ◽  
Experimental Crystal ◽  
The Impact

Dehydration may change the crystal lattice and affect the mosaicity, resolution and quality of X-ray diffraction data. A dehydrating environment can be generated around a crystal in several ways with various degrees of precision and complexity. This study uses a high-precision crystal humidifier/dehumidifier to provide an airstream of known relative humidity in which the crystals are mounted: a precise yet hassle-free approach to altering crystal hydration. A protocol is introduced to assess the impact of crystal dehydration systematically applied to nine experimental crystal systems. In one case, that of glucose isomerase, dehydration triggering a change of space group fromI222 toP21212 was observed. This observation is supported by an extended study of the behaviour of the glucose isomerase crystal structure during crystal dehydration.

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