scholarly journals A procedure for setting up high-throughput nanolitre crystallization experiments. II. Crystallization results

2003 ◽  
Vol 36 (2) ◽  
pp. 315-318 ◽  
Author(s):  
J. Brown ◽  
T. S. Walter ◽  
L. Carter ◽  
N. G. A. Abrescia ◽  
A. R. Aricescu ◽  
...  
Keyword(s):  
Scale Up ◽  
Data Sets ◽  
Molecular Replacement ◽  
Research Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystallization Experiments ◽  
Crystallization Conditions ◽  
Synchrotron Beamlines

An initial tranche of results from day-to-day use of a robotic system for setting up 100 nl-scale vapour-diffusion sitting-drop protein crystallizations has been surveyed. The database of over 50 unrelated samples represents a snapshot of projects currently at the stage of crystallization trials in Oxford research groups and as such encompasses a broad range of proteins. The results indicate that the nanolitre-scale methodology consistently identifies more crystallization conditions than traditional hand-pipetting-style methods; however, in a number of cases successful scale-up is then problematic. Crystals grown in the initial 100 nl-scale drops have in the majority of cases allowed useful characterization of X-ray diffraction, either in-house or at synchrotron beamlines. For a significant number of projects, full X-ray diffraction data sets have been collected to 3 Å resolution or better (either in-house or at the synchrotron) from crystals grown at the 100 nl scale. To date, five structures have been determined by molecular replacement directly from such data and a further three from scale-up of conditions established at the nanolitre scale.

scholarly journals Crystallization and preliminary X-ray characterization of MutT2, MSMEG_5148 fromMycobacterium smegmatis

2014 ◽  
Vol 70 (2) ◽  
pp. 190-192 ◽  
Author(s):  
S. M. Arif ◽  
P. B. Sang ◽  
U. Varshney ◽  
M. Vijayan
Keyword(s):  
Mycobacterium Smegmatis ◽  
Three Dimensional ◽  
Protein Molecule ◽  
Dimensional Structure ◽  
Molecular Replacement ◽  
Nudix Hydrolase ◽  
X Ray Diffraction ◽  
Orthorhombic Unit Cell ◽  
X Ray

Crystallization of MutT2, MSMEG_5148 fromMycobacterium smegmatis, has been carried out and the crystals have been characterized using X-ray diffraction. Matthews coefficient calculation suggests the possibility of one protein molecule in the asymmetric unit of the orthorhombic unit cell, space groupP21212 orP2122. Solution of the structure of the protein by molecular replacement using the known three-dimensional structure of a bacterial Nudix hydrolase is envisaged.

scholarly journals Purification and crystallographic analysis of a FAD-dependent halogenase fromStreptomycessp. JCM9888

2015 ◽  
Vol 71 (8) ◽  
pp. 972-976 ◽  
Author(s):  
Yanqun Zhao ◽  
Baohua Yan ◽  
Ting Yang ◽  
Jian Jiang ◽  
Heng Wei ◽  
...  
Keyword(s):  
Model Building ◽  
Structure Refinement ◽  
Crystallographic Analysis ◽  
Monoclinic Space Group ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Hexahistidine Tag ◽  
Crystallization Experiments

A new FAD (flavin adenine dinucleotide)-dependent halogenase HalY fromStreptomycessp. JCM9888 was reported to be involved in the regioselective halogenation of adenine. HalY is a variant B FAD-dependent halogenase that is most similar to the halogenase PltA involved in pyoluteorin biosynthesis. This study reports the overexpression and purification of HalY with an N-terminal hexahistidine tag, followed by crystallization experiments and X-ray crystallographic analysis. HalY was purified as a monomer in solution and crystallized to give X-ray diffraction to a resolution of 1.7 Å. The crystal belonged to the monoclinic space groupP21, with unit-cell parametersa= 41.4,b= 113.4,c= 47.6 Å, α = γ = 90, β = 107.4°, and contained one monomer of HalY in the asymmetric unit, with a calculated Matthews coefficient of 2.3 Å3 Da−1and a solvent content of 46%. The structure of the halogenase CndH was used as a search model in molecular replacement to obtain the initial model of HalY. Manual model building and structure refinement of HalY are in progress.

scholarly journals Crystallization and X-ray diffraction studies of arginine kinase from the white Pacific shrimpLitopenaeus vannamei

2012 ◽  
Vol 68 (7) ◽  
pp. 783-785 ◽  
Author(s):  
Alonso A. Lopez-Zavala ◽  
Rogerio R. Sotelo-Mundo ◽  
Karina D. Garcia-Orozco ◽  
Felipe Isac-Martinez ◽  
Luis G. Brieba ◽  
...  
Keyword(s):  
Arginine Kinase ◽  
Homology Model ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
The Pacific ◽  
Crystallization Conditions ◽  
Reported Data

Crystals of an unligated monomeric arginine kinase from the Pacific whiteleg shrimpLitopenaeus vannamei(LvAK) were successfully obtained using the microbatch method. Crystallization conditions and preliminary X-ray diffraction analysis to 1.25 Å resolution are reported. Data were collected at 100 K on NSLS beamline X6A. The crystals belonged to space groupP212121, with unit-cell parametersa= 56.5,b= 70.2,c= 81.7 Å. One monomer per asymmetric unit was found, with a Matthews coefficient (VM) of 2.05 Å3 Da−1and 40% solvent content. Initial phases were determined by molecular replacement using a homology model ofLvAK as the search model. Refinement was performed withPHENIX, with finalRworkandRfreevalues of 0.15 and 0.19, respectively. Biological analysis of the structure is currently in progress.

Potential use of ultrasound to promote protein crystallization

2010 ◽  
Vol 43 (6) ◽  
pp. 1419-1425 ◽  
Author(s):  
Rosa Crespo ◽  
Pedro M. Martins ◽  
Luís Gales ◽  
Fernando Rocha ◽  
Ana M. Damas
Keyword(s):  
Protein Crystallization ◽  
Crystal Formation ◽  
Data Sets ◽  
Resolution Limit ◽  
X Ray Diffraction ◽  
Promoting Effect ◽  
X Ray ◽  
X Ray Crystallography ◽  
Egg White Lysozyme ◽  
Crystallization Experiments

This work shows promising applications of ultrasound in promoting protein crystallization, which is important for structure determination by X-ray crystallography. It was observed that ultrasound can be used as a nucleation promoter as it decreases the energy barrier for crystal formation. Crystallization experiments on egg-white lysozyme were carried out with and without ultrasonic irradiation using commercial crystallization plates placed in temperature-controlled water baths. The nucleation-promoting effect introduced by ultrasound is illustrated by the reduction of the metastable zone width, as measured by the isothermal microbatch technique. The same effect was confirmed by the increased number of conditions leading to the formation of crystals when vapour diffusion techniques were carried out in the presence of ultrasound. By inducing faster nucleation, ultrasound leads to protein crystals grown at low supersaturation levels, which are known to have better diffraction properties. In fact, X-ray diffraction data sets collected using 13 lysozyme crystals (seven grown with ultrasound and six without) show an average 0.1 Å improvement in the resolution limit when ultrasound was used (p< 0.10). Besides the immediate application of ultrasound in nucleation promotion, the preliminary diffraction results also suggest a promising application in crystal quality enhancement.

scholarly journals Crystallization and preliminary X-ray analysis of a novel type of lipolytic hydrolase fromBacillus licheniformis

2014 ◽  
Vol 70 (4) ◽  
pp. 473-475
Author(s):  
Hansol Ju ◽  
Ramesh Pandian ◽  
Kyungmin Kim ◽  
Kyeong Kyu Kim ◽  
T. Doohun Kim
Keyword(s):  
Structure Refinement ◽  
Molecular Replacement ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Peg 4000 ◽  
Replacement Solution ◽  
Increasing Demand ◽  
Identification And Characterization

With increasing demand in biotechnological applications, the identification and characterization of novel lipolytic enzymes are of great importance. The crystallization and preliminary X-ray crystallographic study of a novel type of hydrolase fromBacillus licheniformis(BL28) are described here. Recombinant BL28 protein containing a C-terminal His tag was overproduced inEscherichia coliand purified to homogeneity. BL28 was crystallized using 0.2 Mammonium acetate, 0.1 Msodium citrate tribasic dihydrate pH 5.6, 30%(w/v) PEG 4000 as a crystallizing solution. X-ray diffraction data were collected to a resolution of 1.67 Å with anRmergeof 5.8%. The BL28 crystals belonged to the tetragonal space groupP41212, with unit-cell parametersa=b= 57.89,c= 167.25 Å. A molecular-replacement solution was obtained and structure refinement of BL28 is in progress.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

High Resolution Replication of Organoclay Surfaces

1982 ◽  
Vol 40 ◽  
pp. 576-577
Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys
Keyword(s):  
Clay Mineral ◽  
Organic Molecule ◽  
Organic Molecules ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Naturally Occurring ◽  
Silicate Layers ◽  
Mineral Identification

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.

Synthesis and characterization of TiN / Ti / AISI 410 coatings

2018 ◽  
Vol 2 (1) ◽  
pp. 7
Author(s):  
S Chirino ◽  
Jaime Diaz ◽  
N Monteblanco ◽  
E Valderrama
Keyword(s):  
Synthesis And Characterization ◽  
Photoemission Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Columnar Grains ◽  
Tin Thin Films ◽  
Steel Aisi ◽  
Interacting Surfaces ◽  
Stainless Steel Aisi

The synthesis and characterization of Ti and TiN thin films of different thicknesses was carried out on a martensitic stainless steel AISI 410 substrate used for tool manufacturing. The mechanical parameters between the interacting surfaces such as thickness, adhesion and hardness were measured. By means of the scanning electron microscope (SEM) the superficial morphology of the Ti/TiN interface was observed, finding that the growth was of columnar grains and by means of EDAX the existence of titanium was verified.  Using X-ray diffraction (XRD) it was possible to observe the presence of residual stresses (~ -3.1 GPa) due to the different crystalline phases in the coating. Under X-ray photoemission spectroscopy (XPS) it was possible to observe the molecular chemical composition of the coating surface, being Ti-N, Ti-N-O and Ti-O the predominant ones.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

New Coordination Compounds of Fe(III) with Organic Ligands

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Mihaela Flondor ◽  
Ioan Rosca ◽  
Doina Sibiescu ◽  
Mihaela-Aurelia Vizitiu ◽  
Daniel-Mircea Sutiman ◽  
...  
Keyword(s):  
Chemical Analysis ◽  
Complex Compounds ◽  
Organic Ligands ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Chemical Analysis ◽  
Structural Formulae ◽  
Paramagnetic Properties

In this paper the synthesis and the study of some complex compounds of Fe(III) with ligands derived from: 2-(4-chloro-phenylsulfanyl)-1-(2-hydroxy-3,5-diiodo-phenyl)-ethanone (HL1), 1-(3,5-dibromo-2-hydroxy-phenyl)-2-phenylsulfanyl-ethanone(HL2), and 2-(4-chloro-phenylsulfanyl)-1-(3,5-dibromo-2-hydroxy-phenyl)-ethanone (HL3) is presented. The characterization of these complexes is based on method as: the elemental chemical analysis, IR and ESR spectroscopy, M�ssbauer, the thermogravimetric analysis and X-ray diffraction. Study of the IR and chemical analysis has evidenced that the precipitates form are a complexes and the combination ratio of M:L is 1:2. The central atoms of Fe(III) presented paramagnetic properties and a octaedric hybridization. Starting from this precipitation reactions, a method for the gravimetric determination of Fe(III) with this organic ligands has been possible. Based on the experimental data on literature indications, the structural formulae of the complex compounds are assigned.

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