scholarly journals Crystallization and preliminary X-ray diffraction studies of melibiose permease

2020 ◽  
Author(s):  
Yibin Lin
Keyword(s):  
Critical Factor ◽  
Resolution Limit ◽  
X Ray Diffraction ◽  
Protein Preparation ◽  
X Ray ◽  
Transporter Protein ◽  
Crystallization Experiment ◽  
Crystallization Conditions ◽  
Efficient Screening ◽  
Type Crystal

AbstractOur work presented here showed that MelB can be crystallized in the conditions as similar as that of other membrane transporter protein of known structure. To identify a rigid protein by modifying the protein structure is the critical factor for facilitating MelB crystallization. It is necessary to perform extensive crystallization screens to obtain crystals. MelB-MelB interaction in the DDM containing solution will be affect by protein preparation, which may lead to reduce in reproducibility of crystallization experiment. Using a detergent mixture is essential for improve protein contact in the crystals, then improve crystallizability. R149C MelB crystal can be obtained in DDM, but these crystals were only diffracted to about 8Å resolution limit. MelB wide type crystal also can be obtained from the condition as that of R149C mutant, but the resolution is weaker than that of mutant. Although MelB and other transporters of known structure share common feature of the crystallization, the emphasis was as much on the protein itself, as it was on detergent type or efficient screening and refinement of the crystallization conditions.

The Crystal Behaviors of Shortenings Made from Lard and Palm Oil

2011 ◽  
Vol 236-238 ◽  
pp. 2683-2687 ◽  
Author(s):  
Su Xi Wu ◽  
Rui Xin Liu ◽  
Hui Li ◽  
Min Ji
Keyword(s):  
Crystal Structure ◽  
Palm Oil ◽  
Palm Olein ◽  
Diffraction Method ◽  
Palm Stearin ◽  
X Ray Diffraction ◽  
High Quality ◽  
X Ray ◽  
Crystallization Conditions ◽  
Type Crystal

The crystal behaviors of lard- based and palm oil-based shortenings manufactured under different crystallization conditions were studied and compared, by using X-ray diffraction method, in order to decide whether lard can be replaced with cheaper palm oil for the production of shortening. The results showed that lard-based shortenings all exhibited β-type of crystal structure under tested crystallization conditions, whereas those shortenings based on the palm oil or the blend of palm stearin with palm olein presented β-type crystals under the maturation temperature of 20°C and β’-type crystals under the maturation temperature of 25°C～28°C. This study demonstrated that lard-based shorternings do not have β’-type crystal structure, a key character for the production of high quality shortening, and palm oil (including palm stearin and palm olein) is more suitable than lard when used as a solid fat material for the manufacture of shortenings.

Polyhedral characteristics of the cosalite-type crystal structures

2019 ◽  
Vol 57 (5) ◽  
pp. 647-662
Author(s):  
Sabina Kovač ◽  
Predrag Dabić ◽  
Aleksandar Kremenović ◽  
Aleksandar Pačevski ◽  
Ljiiljana Karanović ◽  
...  
Keyword(s):  
Crystal Data ◽  
Chemical Formula ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Area Detector ◽  
Octahedral Sites ◽  
Distorted Octahedral ◽  
Cation Substitutions ◽  
Type Crystal

Abstract The crystal structure of cosalite from the Trepča orefield was refined in the orthorhombic space group Pnma [a = 23.7878 (9), b = 4.0566 (3), c = 19.1026 (8) Å, V = 1843.35 (17) Å3, Z = 2] from single-crystal data (MoKα X-ray diffraction, CCD area detector) to the conventional R1 factor 0.031 for 1516 unique reflections with I > 2σ(I). The chemical formula (Cu0.15Ag0.24)+(Fe0.19Pb7.20)2+(Bi7.06Sb1.06)3+S20, calculated on the basis of 20 S atoms per formula unit, was determined by WDX. The unit cell contains 18 + 2 symmetrically nonequivalent atomic sites: 10 occupied by S; two by pure Pb (Pb3 and Pb4); one by pure Bi (Bi1); two by a combination of Bi and small amounts of Sb (Bi2/Sb2, Bi4/Sb3); two by Pb and Bi, and in one of these also by a small amount of Ag [Me1 = Pb2 >> Bi5 > Ag1, Me3 = Pb1 >> Bi3]; and finally one site, Me2 (Bi6 >> □), is partly occupied by Bi and partly split into an additional two adjacent trigonal planar “interstitial positions”, Cu1 and Cu2, where small amounts of Cu, Ag, and Fe can be situated. All atoms are at 4c special positions at y = 0.25 or 0.75. The structure consists of slightly to moderately distorted MeS6 octahedra sharing edges, bicapped trigonal PbS8 coordination prisms, and fairly distorted Cu1S6 and Cu2S4 polyhedra. The effects of the cation substitutions, bond valence sums, and the polyhedral characteristics are compared with other published cosalite-type structures. Among known cosalite-type structures, the largest volume contraction is shown by sample 4 (Altenberg) and involves the replacement of large cations (Bi3+ and Pb2+) by the smaller Sb3+, as well as Cu+ and Ag+. These replacements are reflected in the variations of individual Me–S bond distances, which are accompanied by variations in average Me–S distances. The degree of polyhedral distortion, Δ, progressively increases for the four Bi-hosting sites of nine cosalite-type structures: Me2 < Bi2 < Bi1 < Bi4. The Bi4 and Me3 are the most and the Me1 and Me2 are the least distorted octahedral sites of the nine cosalite-type structures.

Optimization of Structure of Soft Block for Design of Adaptive Polyurethanes

2020 ◽  
Vol 869 ◽  
pp. 273-279
Author(s):  
Marina A. Gorbunova ◽  
Denis V. Anokhin ◽  
Valentina A. Lesnichaya ◽  
Alexander A. Grishchuk ◽  
Elmira R. Badamshina
Keyword(s):  
Mutual Influence ◽  
Glycol Adipate ◽  
Mass Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystallization Conditions ◽  
Crystalline Domains ◽  
Kinetics Of

A synthesis of new di-and triblock polyurethane thermoplastic copolymers containing different mass ratio of two crystallizing blocks - poly (1,4-butylene glycol) adipate and poly-ε-caprolactone diols was developed. Using combination of danamometric analysis, IR-spectroscopy, differential scanning calorimetry and X-ray diffraction, the effect of the soft block composition and crystallization conditions on crystal structure and thermal behavior of the obtained polymers have been studied. For the triblock copolymers we have shown a possibility of control the kinetics of material hardening and final mechanical characteristics due to the mutual influence of polydiols during crystallization. In the result, the second crystallizing component allows to control amount, structure and quality of crystalline domains in polyurethanes by variation of crystallization conditions.

Diffraction apparatus and procedure in tomography X-ray diffraction imaging for biological cells at cryogenic temperature using synchrotron X-ray radiation

2018 ◽  
Vol 25 (6) ◽  
pp. 1803-1818 ◽  
Author(s):  
Amane Kobayashi ◽  
Yuki Takayama ◽  
Koji Okajima ◽  
Mao Oide ◽  
Takahiro Yamamoto ◽  
...  
Keyword(s):  
Dimensional Structure ◽  
Cyanidioschyzon Merolae ◽  
Specimen Preparation ◽  
Biological Cells ◽  
Cryogenic Temperatures ◽  
Resolution Limit ◽  
X Ray Diffraction ◽  
Experimental Conditions ◽  
X Ray ◽  
Diffraction Imaging

X-ray diffraction imaging is a technique for visualizing the structure of biological cells. In X-ray diffraction imaging experiments using synchrotron radiation, cryogenic conditions are necessary in order to reduce radiation damage in the biological cells. Frozen-hydrated biological specimens kept at cryogenic temperatures are also free from drying and bubbling, which occurs in wet specimens under vacuum conditions. In a previous study, the diffraction apparatus KOTOBUKI-1 [Nakasako et al. (2013), Rev. Sci. Instrum. 84, 093705] was constructed for X-ray diffraction imaging at cryogenic temperatures by utilizing a cryogenic pot, which is a cooling device developed in low-temperature physics. In this study a new cryogenic pot, suitable for tomography experiments, has been developed. The pot can rotate a biological cell over an angular range of ±170° against the direction of the incident X-ray beam. Herein, the details and the performance of the pot and miscellaneous devices are reported, along with established experimental procedures including specimen preparation. The apparatus has been used in tomography experiments for visualizing the three-dimensional structure of a Cyanidioschyzon merolae cell with an approximate size of 5 µm at a resolution of 136 nm. Based on the experimental results, the necessary improvements for future experiments and the resolution limit achievable under experimental conditions within a maximum tolerable dose are discussed.

Investigations on electrical conduction properties and crystallization conditions of V2O5-P2O5 glass based semiconductors

2013 ◽  
Vol 1494 ◽  
pp. 215-219
Author(s):  
Akifumi Matsuda ◽  
Takuya Aoyagi ◽  
Takashi Naito ◽  
Tadashi Fujieda ◽  
Kenjiro Ikejiri ◽  
...  
Keyword(s):  
High Vacuum ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
Melt Quenching ◽  
X Ray ◽  
Heat Treated ◽  
Crystallization Conditions ◽  
Quenching Method ◽  
Vanadate Glasses ◽  
Conduction Properties

ABSTRACTWe studied the electrical properties of thermally treated V2O5-CuO-Fe2O3-P2O5 (vanadate) glasses under reducing high-vacuum conditions. The glasses were prepared by using a melt-quenching method and then applied on Al2O3 substrates as ∼40μm-thick films. The glass films were then heat treated at 375−550°C under a vacuum of 10−6 Pa. Powder X-ray diffraction showed the formation of complex oxides of both MxV2O5 (M = Cu, Fe; x = 0.12−1.3) and vanadium oxides (VOx; x = 1.5−2.5). The resistivity of the glass film crystallized at 550°C measured at 50°C and 300°C were 1.8 × 100 Ωcm and 2.8 × 10−1 Ωcm, respectively, which was 10 times lower than that of the film crystallized in air. The Seebeck coefficient was −132 μV/K at 50°C and −130 μV/K at 300°C. These results show that the vanadate glasses crystallized under the appropriate condition become potential candidate materials for semiconductor and thermoelectric application.

scholarly journals Crystallization and preliminary X-ray diffraction analysis of the homing endonuclease I-CvuI fromChlorella vulgarisin complex with its target DNA

2014 ◽  
Vol 70 (2) ◽  
pp. 256-259 ◽  
Author(s):  
Pilar Redondo ◽  
Nekane Merino ◽  
Maider Villate ◽  
Francisco J. Blanco ◽  
Guillermo Montoya ◽  
...  
Keyword(s):  
Diffraction Analysis ◽  
Homing Endonuclease ◽  
Homing Endonucleases ◽  
Resolution Limit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Strand Breaks ◽  
X Ray ◽  
Cell Parameters ◽  
Wide Range

Homing endonucleases are highly specific DNA-cleaving enzymes that recognize long stretches of DNA. The engineering of these enzymes provides novel instruments for genome modification in a wide range of fields, including gene targeting, by inducing specific double-strand breaks. I-CvuI is a homing endonuclease from the green algaChlorella vulgaris. This enzyme was purified after overexpression inEscherichia coli. Crystallization experiments of I-CvuI in complex with its DNA target in the presence of Mg2+yielded crystals suitable for X-ray diffraction analysis. The crystals belonged to the orthorhombic space groupP212121, with unit-cell parametersa= 62.83,b= 83.56,c= 94.40 Å. The self-rotation function and the Matthews coefficient suggested the presence of one protein–DNA complex per asymmetric unit. The crystals diffracted to a resolution limit of 1.9 Å using synchrotron radiation.

X-ray diffraction data and Rietveld refinement of CuGaxIn1-xSe2 (x=0.15 and 0.50)

2010 ◽  
Vol 25 (3) ◽  
pp. 253-257 ◽  
Author(s):  
E. J. Friedrich ◽  
R. Fernández-Ruiz ◽  
J. M. Merino ◽  
M. León
Keyword(s):  
Rietveld Refinement ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zinc Blende ◽  
Metal Atoms ◽  
Tetragonal Crystal ◽  
Unit Cells ◽  
Type Crystal

X-ray powder diffraction data for CuGa0.15In0.85Se2 and CuGa0.50In0.50Se2 are reported. Indexing of the X-ray diffraction powder pattern and the Rietveld refinement confirmed that these compounds crystallize in the tetragonal crystal system, with space group I-42d (No. 122) and lattice parameters of a=5.7528(2) Å and c=11.5225(3) Å for CuGa0.15In0.85Se2 and a=5.6847(1) Å and c=11.2817(1) Å for CuGa0.50In0.50Se2. The CuGaxIn1−xSe2 system presents the chalcopyrite type crystal structure (CuFeS2) and corresponds to two stacked zinc-blende unit cells. The metal atoms Cu, In, and Ga are regularly ordered in the unit cell. Every Se atom is tetrahedrally bonded to two Cu and two In and Ga atoms.

scholarly journals Crystallization via tubing microfluidics permits both in situ and ex situ X-ray diffraction

2017 ◽  
Vol 73 (10) ◽  
pp. 574-578 ◽  
Author(s):  
Charline J. J. Gerard ◽  
Gilles Ferry ◽  
Laurent M. Vuillard ◽  
Jean A. Boutin ◽  
Leonard M. G. Chavas ◽  
...  
Keyword(s):  
Ex Situ ◽  
X Ray Diffraction ◽  
Microfluidic Platform ◽  
X Ray ◽  
Crystallization Conditions

A microfluidic platform was used to address the problems of obtaining diffraction-quality crystals and crystal handling during transfer to the X-ray diffractometer. Crystallization conditions of a protein of pharmaceutical interest were optimized and X-ray data were collected both in situ and ex situ.

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