Crystallization of high-quality protein crystals using an external electric field

2015 ◽  
Vol 48 (5) ◽  
pp. 1507-1513 ◽  
Author(s):  
H. Koizumi ◽  
S. Uda ◽  
K. Fujiwara ◽  
M. Tachibana ◽  
K. Kojima ◽  
...  
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Applied Field ◽  
Local Strain ◽  
Protein Crystal ◽  
X Ray Diffraction ◽  
High Quality Protein ◽  
Hen Egg White ◽  
Lysozyme Crystals

The effect of a 20 kHz external electric field on the quality of tetragonal hen egg white (HEW) lysozyme crystals was investigated using X-ray diffraction rocking-curve measurements. The full width at half-maximum was found to be larger for high-order reflections but smaller for low-order reflections. In particular, it was revealed that a large amount of local strain is accumulated in tetragonal HEW lysozyme crystals grown under an applied field at 20 kHz. Comparison with previous results obtained for crystals grown with an applied field at 1 MHz [Koizumi, Uda, Fujiwara, Tachibana, Kojima & Nozawa (2013).J. Appl. Cryst.46, 25–29] indicated that improvement of the protein crystal quality could be achieved by selection of an appropriate frequency for the applied electric field, which has a significant effect on the growth of the solid.

Lateral deformations of a crystal of potassium acid phthalate in an external electric field

2021 ◽  
Vol 54 (5) ◽  
pp. 1317-1326
Author(s):  
Arsen Petrenko ◽  
Nataliya Novikova ◽  
Alexander Blagov ◽  
Anton Kulikov ◽  
Yury Pisarevskii ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Electric Field ◽  
External Electric Field ◽  
Applied Field ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

The anisotropy of deformations in potassium acid phthalate crystals arising under the action of an external electric field up to 1 kV mm−1 applied along the [001] polar axis was studied using X-ray diffraction methods at room temperature. Electrical conductivity was measured and rocking curves for reflections 400, 070 and 004 were obtained by time-resolved X-ray diffractometry in Laue and Bragg geometries. Two saturation processes were observed from the time dependences of the electrical conductivity. A shift in the diffraction peaks and a change in their intensity were found, which indicated a deformation of the crystal structure. Rapid piezoelectric deformation and reversible relaxation-like deformation, kinetically similar to the electrical conductivity of a crystal, were revealed. The deformation depended on the polarity and strength of the applied field. The deformation was more noticeable in the [100] direction and was practically absent in the [001] direction of the applied field. X-ray diffraction analysis revealed a disordered arrangement of potassium atoms, i.e. additional positions and vacancies. The heights of potential barriers between the positions of K+ ions and the paths of their possible migration in the crystal structure of potassium acid phthalate were determined. The data obtained by time-resolved X-ray diffractometry and X-ray structure analysis, along with additional electrophysical measurements, allow the conclusion that the migration of charge carriers (potassium cations) leads to lateral deformation of the crystal structure of potassium phthalate in an external electric field.

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.

scholarly journals Technique for High-Quality Protein Crystal Growth by Control of Subgrain Formation under an External Electric Field

Crystals ◽  
2016 ◽  
Vol 6 (8) ◽  
pp. 95 ◽  
Author(s):  
Haruhiko Koizumi ◽  
Satoshi Uda ◽  
Kozo Fujiwara ◽  
Masaru Tachibana ◽  
Kenichi Kojima ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Electric Field ◽  
External Electric Field ◽  
Protein Crystal ◽  
High Quality ◽  
High Quality Protein ◽  
Protein Crystal Growth ◽  
Subgrain Formation

Use of an External Electric Field to Convert the Paraelectric Phase to the Ferroelectric Phase in Ultra-thin Copolymer Films of P(VDF-TrFE)

2000 ◽  
Vol 655 ◽  
Author(s):  
Matt Poulsen ◽  
S. Adenwalla ◽  
Stephen Ducharme ◽  
V.M. Fridkin ◽  
S.P. Palto ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electric Field ◽  
External Electric Field ◽  
Ferroelectric Phase ◽  
Paraelectric Phase ◽  
Continuous Process ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
Layer Spacing ◽  
X Ray

AbstractX-ray diffraction was used to probe the structural changes associated with the conversion of the paraelectric phase to the ferroelectric phase that results from the application of a large external electric field. The samples under study are ultrathin (150 to 250 Å) Langmuir-Blodgett films of the copolymer vinylidene fluoride (70%) with trifluoroethylene (30%) deposited on aluminum-coated silicon. Theta-2theta X-ray diffraction was used to measure the change in inter-layer spacing perpendicular to the film surface. Upon heating at zero external electric field, the crystalline films undergo a structural phase transition, at 100± 5°C, from the all-trans ferroelectric phase to the trans-gauche paraelectric phase. [1,2] Above the phase transition temperature, the non-polar paraelectric phase can be converted back to the polar ferroelectric phase, in a smooth continuous process, using a large external electric field (∼1 GV/m). For example, at 100° C the ferroelectric phase first appears above 0.2 GV/m and increases steadily in proportion while the paraelectric phase decreases until complete conversion to the ferroelectric phase is achieved at approximately 0.6 GV/m.

Numerical Analysis of the Diffusive Field around a Growing Protein Crystal in Microgravity

2012 ◽  
Vol 323-325 ◽  
pp. 565-569 ◽  
Author(s):  
Koji Inaka ◽  
Hiroaki Tanaka ◽  
Sachiko Takahashi ◽  
Satoshi Sano ◽  
Masaru Sato ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Kinetic Constant ◽  
Protein Crystal ◽  
Microgravity Environment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microgravity Experiments ◽  
Space Agency ◽  
Filtration Effect

t is believed that a microgravity environment may maintain ideal depletion zones of protein (PDZ) and impurity (IDZ) around growing crystals and may contribute to growing high-quality crystals. This can lead to an X-ray diffraction data collection of higher resolution with lower mosaicity, because of the better internal order and fewer defects in the crystals when compared to ground-grown crystals. The extent of these depletion zones are dependent on a competition between the diffusion of the molecules in the solution (indexed by the diffusion coefficient, D) and the adsorption of those into the growing crystal (indexed by the kinetic constant, β). If we use the D/β value as an index of the extent of PDZ and IDZ, a lower D/β value is ideal for maintaining PDZ and IDZ. Using experimental results, we could easily obtain the D/β value. When we combined the D/β value with the quality of protein crystals obtained in microgravity experiments provided by Japanese Space Agency (JAXA), we found that the effects of microgravity contributed to obtaining superior crystals especially if the D/β value was less than 3 mm. The numerical analysis of the PDZ and IDZ shows that the radius of the crystal (R) is also related to the PDZ and the IDZ. If the Rβ/D value is large, both the PDZ and the IDZ provide a filtration effect, but if the Rβ/D value is small, only the IDZ does.

scholarly journals X-ray diffraction study of chemical bonds under external electric field

2006 ◽  
Vol 62 (a1) ◽  
pp. s171-s171
Author(s):  
S. Gorfman ◽  
O. Schmidt ◽  
M. Schmidt ◽  
H. Borrmann ◽  
Y. Grin ◽  
...  
Keyword(s):  
Electric Field ◽  
Diffraction Study ◽  
External Electric Field ◽  
Chemical Bonds ◽  
X Ray Diffraction ◽  
X Ray
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