A simple technique to control macromolecular crystal nucleation efficiently using a standard vapour-diffusion setup

2000 ◽  
Vol 33 (3) ◽  
pp. 988-989 ◽  
Author(s):  
Luca Jovine
Keyword(s):  
Data Collection ◽  
Diffraction Analysis ◽  
Vapour Pressure ◽  
Simple Technique ◽  
Crystal Nucleation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vapour Diffusion ◽  
Discrete Amount ◽  
Set Up

Excessive nucleation often leads to a large number of small macromolecular crystals that are not useful for X-ray diffraction analysis. Crystals with dimensions suitable for data collection can be reproducibly obtained by releasing, for a discrete amount of time, the vapour pressure in both hanging- and sitting-drop experiments, set up at lower precipitant concentrations than those required for crystallization.

Overproduction, purification, crystallization and preliminary X-ray diffraction studies of the human spliceosomal protein U5-15kD

1999 ◽  
Vol 55 (4) ◽  
pp. 888-890 ◽  
Author(s):  
Klaus Reuter ◽  
Ralf Ficner
Keyword(s):  
Escherichia Coli ◽  
Data Collection ◽  
Diffusion Method ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Gene Coding ◽  
Vapour Diffusion ◽  
Spliceosomal Protein

The gene coding for the human spliceosomal U5 snRNP-specific 15 kDa protein (U5-15kD) was overexpressed in Escherichia coli, its product purified to homogeneity and crystallized. Well diffracting single crystals were obtained by the vapour-diffusion method in hanging drops and subsequent macroseeding. The crystals belong to the orthorhombic space group P21212 with a = 62.3, b = 65.7, c = 37.1 Å. They diffract to at least 3.0 Å and contain one molecule in the asymmetric unit. A selenomethionine derivative of the protein was prepared and crystallized for multiwavelength anomalous diffraction (MAD) data collection.

scholarly journals A simple technique to reduce evaporation of crystallization droplets by using plate lids with apertures for adding liquids

2014 ◽  
Vol 70 (12) ◽  
pp. 1707-1713 ◽  
Author(s):  
Lauren E. Zipper ◽  
Xavier Aristide ◽  
Dylan P. Bishop ◽  
Ishita Joshi ◽  
Julia Kharzeev ◽  
...  
Keyword(s):  
Droplet Size ◽  
Simple Technique ◽  
X Ray Diffraction ◽  
X Ray ◽  
Air Movement ◽  
Design Changes ◽  
Crystallization Experiments ◽  
Low Volume ◽  
Set Up ◽  
Rate Of Evaporation

A method is described for using plate lids to reduce evaporation in low-volume vapor-diffusion crystallization experiments. The plate lids contain apertures through which the protein and precipitants were added to different crystallization microplates (the reservoir was filled before fitting the lids). Plate lids were designed for each of these commonly used crystallization microplates. This system minimizes the dehydration of crystallization droplets containing just a few nanolitres of protein and precipitant, and results in more reproducible diffraction from the crystals. For each lid design, changes in the weight of the plates were used to deduce the rate of evaporation under different conditions of temperature, air movement, droplet size and precipitant. For comparison, the state of dehydration was also visually assessed throughout the experiment. Finally, X-ray diffraction methods were used to compare the diffraction of protein crystals that were conventionally prepared against those that were prepared on plates with plate lids. The measurements revealed that the plate lids reduced the rate of evaporation by 63–82%. Crystals grown in 5 nl drops that were set up with plate lids diffracted to higher resolution than similar crystals from drops that were set up without plate lids. The results demonstrate that plate lids can be instrumental for improving few-nanolitre crystallizations.

scholarly journals Paragenesis Prospek Endapan Bijih Besi Daerah Tanjung Kecamatan Bontocani Kabupaten Bone, Sulawesi Selatan

2021 ◽  
Vol 9 (2) ◽  
pp. 179-186
Author(s):  
Hasbi Bakri ◽  
Harwan Harwan ◽  
Alam Budiman Thamsi ◽  
Irzal Nur ◽  
Firdaus F ◽  
...  
Keyword(s):  
Data Collection ◽  
Diffraction Analysis ◽  
Iron Ore ◽  
Laboratory Analysis ◽  
Field Conditions ◽  
Mineral Deposits ◽  
X Ray Diffraction ◽  
X Ray ◽  
Random Samples ◽  
Data Collection Technique

Iron ore is the second most abundant metal on earth. The characteristics of this iron ore usually consist of iron ore carrier minerals associated with other minerals. One area that has iron ore prospects is the Tanjung area, Bontocani District, Bone Regency. The purpose of this study was to determine the types of iron ore carrier minerals and their associations, mineralization characteristics and paragenesis of iron ore carrier minerals. The data collection technique is carried out directly in the field by taking random samples in the field according to field conditions. Laboratory analysis uses mineragraphic analysis to determine iron ore carrier minerals and their associated minerals and X-Ray Diffraction analysis to determine iron ore carrier minerals that are not identified by mineragraphic analysis. From the results of the study found iron ore carrier minerals magnetite, goethite and hematite and their associated minerals in the form of sulfide minerals in the form of pyrite, covelite and braunite. The iron ore textures found are replacement and intergrowth textures. Paragenesis of mineral deposits formed successively are magnetite, hematite, pyrite, cuprite, braunite and goethite.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Ten-Vertex Polyhedral Monocarbaborane Chemistry. The Novel High-Yield Formation of the Ten-Vertex closo Compound [6-(PMe2Ph)-closo-1-CB9H9] from the Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11]

1993 ◽  
Vol 58 (12) ◽  
pp. 2924-2935 ◽  
Author(s):  
Jane H. Jones ◽  
Bohumil Štíbr ◽  
John D. Kennedy ◽  
Mark Thornton-Pett
Keyword(s):  
Nmr Spectroscopy ◽  
Diffraction Analysis ◽  
High Yield ◽  
Monoclinic Space Group ◽  
The Novel ◽  
X Ray Diffraction ◽  
Metal Centre ◽  
X Ray ◽  
Yield Formation ◽  
Boiling Toluene

Thermolysis of [8,8-(PMe2Ph)2-nido-8,7-PtCB9H11] in boiling toluene solution results in an elimination of the platinum centre and cluster closure to give the ten-vertex closo species [6-(PMe2Ph)-closo-1-CB9H9] in 85% yield as a colourles air stable solid. The product is characterized by NMR spectroscopy and single-crystal X-ray diffraction analysis. Crystals (from hexane-dichloromethane) are monoclinic, space group P21/c, with a = 903.20(9), b = 1 481.86(11), c = 2 320.0(2) pm, β = 97.860(7)° and Z = 8, and the structure has been refined to R(Rw) = 0.045(0.051) for 3 281 observed reflections with Fo > 2.0σ(Fo). The clean high-yield elimination of a metal centre from a polyhedral metallaborane or metallaheteroborane species is very rare.

Bis(μ-carboxylato)dienerhodium(I) Complexes - Synthesis, Characterization and Catalytic Activity

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1205-1221 ◽  
Author(s):  
Jiří Zedník ◽  
Jan Sedláček ◽  
Jan Svoboda ◽  
Jiří Vohlídal ◽  
Dmitrij Bondarev ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Diffraction Analysis ◽  
Spectroscopic Methods ◽  
X Ray Diffraction ◽  
X Ray

Dinuclear rhodium(I) η2:η2-cycloocta-1,5-diene (series a) and η2:η2-norborna-2,5-diene (series b) complexes with μ-RCOO- ligands, where R is linear C21H43 (complexes 1a, 1b), CH2CMe3 (2a, 2b), 1-adamantyl (3a, 3b) and benzyl (4a, 4b), have been prepared and characterized by spectroscopic methods. Structures of complexes 2b, 3a and 4a were determined by X-ray diffraction analysis. Complexes prepared show low to moderate catalytic activity in polymerization of phenylacetylene in THF giving high-cis-transoid polymers, but they show only oligomerization activity in dichloromethane.

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