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Crystallographic Study (crystallographic + study)
Kinds of Crystallographic Study Selected AbstractsStructure Investigation of Bridgehead Aziridine: Synthesis, Theoretical, and Crystallographic Study of 2,4,6-Triphenyl-1,3-diazabicyclo[3.1.0]hex-3-eneHELVETICA CHIMICA ACTA, Issue 2 2006Giuseppe Bruno Abstract A one-pot three-component procedure to efficiently create the 1,3-diazabicyclo[3.1.0]hex-3-ene system is reported. The molecular structure of 2,4,6-triphenyl-1,3-diazabicyclo[3.1.0]hex-3-ene (3) was studied by X-ray diffraction and compared to ab initio and density-functional-theory (DFT) calculations restricted to the core moiety. Geometry optimizations for structural isomers and tautomeric forms of this aziridine fragment, taken as simplified models, were carried out at high calculation levels. Moreover, the same methods were utilized to evaluate the proton affinity of two crucial aziridine tautomers. [source] ChemInform Abstract: Synthesis, Characterization, and Crystallographic Study of the PbO,Bi2O3,V2O5 System: Pb3-xBi2x/3V2O8 (0.20 , x , 0.50).CHEMINFORM, Issue 35 2010Prangya Parimita Sahoo Abstract The new title solid solution is synthesized by solid state reaction of stoichiometric mixtures of PbO, Bi2O3, and V2O5 (650 °C, 2 d). [source] Spectroscopic, Magnetochemical, and Crystallographic Study of Cesium Iron Phosphate Hexahydrate: Characterization of the Electronic Structure of the Iron(II) Hexa-aqua Cation in a Quasicubic Environment.CHEMINFORM, Issue 35 2006Graham Carver Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Crystallographic study of wild-type carbonic anhydrase ,CA1 from Chlamydomonas reinhardtiiACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2010Kaoru Suzuki Carbonic anhydrases (CAs) are ubiquitously distributed and are grouped into three structurally independent classes (,CA, ,CA and ,CA). Most ,CA enzymes are monomeric, but ,CA1 from Chlamydomonas reinhardtii is a dimer that is uniquely stabilized by disulfide bonds. In addition, during maturation an internal peptide of 35 residues is removed and three asparagine residues are glycosylated. In order to obtain insight into the effects of these structural features on CA function, wild-type C. reinhardtii,CA1 has been crystallized in space group P65, with unit-cell parameters a = b = 134.3, c = 120.2,Å. The crystal diffracted to 1.88,Å resolution and a preliminary solution of its crystal structure has been obtained by the MAD method. [source] Crystallographic study of G178S mutant of human proliferating cell nuclear antigenACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2008Asami Hishiki Proliferating cell nuclear antigen (PCNA) is an evolutionarily conserved protein that forms a ring-shaped homotrimer that functions as a sliding clamp for DNA replication. The rev6-1 mutation of Saccharomyces cerevisiae, which inactivates both translesion DNA synthesis and damage-avoidance pathways while having little effect on normal cell growth, has a G178S substitution in the PCNA protein. Human PCNA protein carrying the G178S substitution was crystallized. Two crystal forms were obtained under similar conditions. Crystal forms I and II belong to space groups P21, with unit-cell parameters a = 84.1, b = 130.2, c = 97.8,Å, , = 113.4°, and P212121, with unit-cell parameters a = 68.1, b = 100.2, c = 131.2,Å, respectively. Structural analyses by molecular replacement are now in progress. [source] Synthesis and Characterization of MoOI2(PMe3)3 and Use of MoOX2(PMe3)3 (X = Cl, I) in Controlled Radical PolymerizationEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2006José A. Mata Abstract Complex MoOCl2(PMe3)3 smoothly reacts with NaI in acetone to produce MoOI2(PMe3)3 in good yields. The geometry of the compound is mer - cis octahedral, that is, identical to that of the dichloride precursor, as shown by NMR spectroscopy and by an X-ray crystallographic study. Electrochemical investigations of MoOX2(PMe3)3 show irreversible oxidation waves at Ep,a = +0.18 and +0.39 V for X = Cl and I, respectively. A study of the halide exchange between MoOCl2(PMe3)3 and NaI, or between MoOI2(PMe3)3 and Bu4NCl, shows two equilibrated isomers for the mixed halide intermediate MoOICl(PMe3)3. The diiodide complex rapidly exchanges the iodo ligands with chloride upon dissolution in chloroform at room temperature, and with bromide from (1-bromoethyl)benzene (BEB) under more forcing conditions. The equilibrium favors the softer halide (I) on C and the harder one (Cl or Br) on MoIV. Both oxido compounds catalyze the atom transfer radical polymerization (ATRP) of styrene in combination with the BEB initiator, yielding polymers with quite narrow molecular weight distributions (down to 1.11). The apparent polymerization rate constant is approximately doubled in the presence of 1 equiv. of the Al(OiPr)3 cocatalyst. On the other hand, the system is not capable of efficiently controlling the radical chain growth for methyl acrylate polymerization. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Novel Bonding Modes between Tetrathiafulvalenes (TTFs) and Transition Metal Centers: ,-Bonding and Covalent TTFSiMe2,MLn Coordination to PlatinumEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2004Mathuresh N. Jayaswal Abstract Two novel strategies for coordinating TTF to transition metal centers have been developed. The reaction of tetrathiafulvalene (TTF) or 3,4-dimethyltetrathiafulvalene (o -Me2TTF) with [Pt(,2 -C2H4)(PPh3)2] leads to the , complexes [Pt(,2 -TTF)(PPh3)2] (1) and [Pt(,2 - o -Me2TTF)(PPh3)2] (2), respectively. An X-ray crystallographic study performed on 2 confirmed, that TTFs act as a , acidic ligand. NMR studies revealed the existence, in solution, of an equilibrium between free and complexed TTF. Dilithiation of o -Me2TTF and subsequent silylation with ClSiMe2H afforded 3,4-dimethyl-3,,4,-(dimethylsilyl)tetrathiafulvalene (3), which has been structurally characterized. 3 reacts by oxidative addition across [Pt(,2 -C2H4)(PPh3)2] to give [Pt{,2 - o -(SiMe2)2TTFMe2}(PPh3)2] (4), in which the TTF ligand is covalently ligated to platinum via SiMe2 bridges. The redox properties of 3 and 4 have been investigated by cyclic voltammetry. Strong cathodic shifts of the two redox processes were observed for 4, implying the TTF core. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] Structure determination and conformation analysis of symmetrical dimersMAGNETIC RESONANCE IN CHEMISTRY, Issue 3 2005Alexei V. Buevich Abstract Conformational and stereochemical analysis of six new symmetrical dimers was performed using proton,proton vicinal coupling measured from 1H NMR and 13C satellites of 1H NMR signals, natural abundance 13C-edited nuclear overhauser effect (NOE) experiments, comprehensive NOE analysis and molecular modeling. The 13C satellite analysis and 13C-edited NOE experiments were carried out to extract spectral information between equivalent protons. Molecular modeling was applied for estimations of three-dimensional parameters of the studied dimers, which were subsequently used to generate a set of theoretical NOE for each possible conformation. The J -coupling, 13C-edited NOE and quantitative NOE analyses showed the predominance of gauche conformation for three dimers, whereas a mixture of gauche and anti conformations (45:55) for three other dimers was established by quantitative NOE analysis. X-ray crystallographic study confirmed the stereochemistry of one of the dimers and revealed a discrepancy in conformation stability between liquid and solid states. Copyright © 2004 John Wiley & Sons, Ltd. [source] Change in electronic structure in a six-coordinate copper(II) complex accompanied by an anion order/disorder transitionACTA CRYSTALLOGRAPHICA SECTION B, Issue 2 2010Colin A. Kilner A variable-temperature crystallographic study of [Cu(LOH)2][ClO4]2·2(CH3)2CO [LOH = 2,6-bis(hydroxyiminomethyl)pyridine] between 30 and 300,K is presented. The complex exhibits an unusual electronic structure at room temperature with a {}1 ground state, corresponding to an axially compressed ligand coordination geometry about the copper ion. This reflects a suppression of the pseudo-Jahn,Teller distortion that is normally shown by copper(II) compounds with this ligand geometry [Halcrow et al. (2004). New J. Chem.28, 228,233]. On cooling the compound undergoes an abrupt structural change at 157,±,3,K, that does not involve a change in the space group (P), but causes significant changes to c and the unit-cell angles. This reflects a conformational rearrangement of the complex dication, towards a more typical pseudo-Jahn,Teller elongated coordination geometry. This occurs concurrently with a crystallographic ordering of one of the two perchlorate anions, and a significant displacement of the two lattice acetone molecules. The transformation involves displacements of up to 0.5,Å in the non-H atoms of the structure at 30,K, compared with their positions at 300,K. The change in coordination geometry of the complex around 157,K is reflected in a small reduction in its magnetic moment near that temperature. [source] Inhibitory properties and X-ray crystallographic study of the binding of AR-101, AR-102 and iclaprim in ternary complexes with NADPH and dihydrofolate reductase from Staphylococcus aureusACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2009Christian Oefner Iclaprim is a novel dihydrofolate reductase (DHFR) inhibitor belonging to the 2,4-diaminopyrimidine class of antibiotics, of which trimethoprim (TMP) is the most well known representative. Iclaprim exhibits potent bactericidal activity against major Gram-positive pathogens, notably methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) phenotypes, including TMP-resistant strains. The inhibition properties of racemic iclaprim and of the two enantiomers, termed AR-101 and AR-102, towards S. aureus wild-type DHFR and TMP-resistant F98Y mutant DHFR were determined and compared. Similar to TMP, AR-101, AR-102 and iclaprim are all competitive inhibitors with respect to the substrate dihydrofolate. Iclaprim, AR-101 and AR-102 demonstrated little or no difference in activity towards these enzymes and were significantly more potent than TMP. The crystal structures of S. aureus DHFR and F98Y mutant DHFR were determined as ternary complexes with NADPH and either AR-101, AR-102 or iclaprim. The binding modes of the inhibitors were analysed and compared. The X-ray crystallographic data explain the binding modes of all molecules well and can be used to rationalize the equipotent affinity of AR-101, AR-102 and iclaprim, which is also reflected in their antibacterial properties. [source] Crystallization and preliminary X-ray crystallographic study of leucyl-tRNA synthetase from the archaeon Pyrococcus horikoshiiACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2004Ryuya Fukunaga The leucyl-tRNA synthetase (LeuRS) from the archaeon Pyrococcus horikoshii was overexpressed in a C-terminally truncated form in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitant. The crystals belong to the rhombohedral space group R3, with unit-cell parameters a = b = 186.20, c = 91.43,Å, , = , = 90, , = 120°. The asymmetric unit contains one molecule of LeuRS, with a corresponding crystal volume per protein weight of 3.2,Å3,Da,1 and a solvent content of 60.7%. A data set diffracting to 2.2,Å resolution was collected from a single crystal at 100,K. Selenomethionine-substituted protein crystals were prepared in order to solve the structure by the SAD phasing method. [source] Expression, refolding, crystallization and preliminary crystallographic study of MHC H-2Kk complexed with octapeptides and nonapeptidesACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2004Christine Kellenberger Major histocompatibility complex (MHC) molecules are heterodimeric cell-surface receptors that play a crucial role in the cellular immune response by presenting epitope peptides to T-cell antigen receptors (TCR). Although the structural basis of the peptide,MHC binding mechanism is becoming better understood, it is still difficult to predict a binding mode for an MHC of unknown structure. Therefore, as the first stage of a TCR,MHC interaction study, the crystal structures of the mouse H-2Kk molecule in complex with both an octapeptide from Influenza A virus and a nonapeptide from simian virus SV40 were solved. Here, the expression, refolding, purification and crystallization of the two complexes are reported. For the H-2Kk,HA(259,266) complex, crystals were obtained via an extensive screen using a nanodrop-dispensing robot and diffracted to 2.5,Å resolution. For the H-2Kk,SV40(560,568) complex, microscopic needles were initially obtained and their size was improved by macroseeding and a stepwise increase in precipitant concentration. Diffraction data to a resolution of 3.0,Å were collected at a synchrotron facility. [source] Crystallization and preliminary crystallographic study of the functional form of the Bacillus thuringiensis mosquito-larvicidal Cry4Aa mutant toxinACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2004Panadda Boonserm The 65,kDa functional form of the mosquito-larvicidal Cry4Aa-R235Q mutant toxin has been crystallized. The crystals belong to space group C2221, with unit-cell parameters a = 91.2, b = 202.1, c = 98.7,Å, and contain one molecule per asymmetric unit. The crystals diffract to ,2.9,Å using synchrotron radiation and a complete native data set has been collected. The structure has been solved using a molecular-replacement method with the Cry4Ba toxin protein as a search model. [source] Crystallization and preliminary X-ray crystallographic study on a xyloglucan-specific exo-,-glycosidase, oligoxyloglucan reducing-end specific cellobiohydrolaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2003Katsuro Yaoi A novel xyloglucan-specific exo-,-glycosidase, oligoxyloglucan reducing-end specific cellobiohydrolase (OXG-RCBH), recognizes the reducing end of oligoxyloglucan and releases two glucosyl residue segments from the main chain. OXG-RCBH was crystallized by the hanging-drop vapour-diffusion method with polyethylene glycol 3000 and polyethylene glycol 400,as precipitants. The crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 61.0, b = 146.9, c = 211.9,Å. The crystals diffract to a resolution of 2.2,Å and are suitable for X-ray structure analysis. [source] Structural genomics of the SARS coronavirus: cloning, expression, crystallization and preliminary crystallographic study of the Nsp9 proteinACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2003Valérie Campanacci The aetiologic agent of the recent epidemics of Severe Acute Respiratory Syndrome (SARS) is a positive-stranded RNA virus (SARS-CoV) belonging to the Coronaviridae family and its genome differs substantially from those of other known coronaviruses. SARS-CoV is transmissible mainly by the respiratory route and to date there is no vaccine and no prophylactic or therapeutic treatments against this agent. A SARS-CoV whole-genome approach has been developed aimed at determining the crystal structure of all of its proteins or domains. These studies are expected to greatly facilitate drug design. The genomes of coronaviruses are between 27 and 31.5,kbp in length, the largest of the known RNA viruses, and encode 20,30 mature proteins. The functions of many of these polypeptides, including the Nsp9,Nsp10 replicase-cleavage products, are still unknown. Here, the cloning, Escherichia coli expression, purification and crystallization of the SARS-CoV Nsp9 protein, the first SARS-CoV protein to be crystallized, are reported. Nsp9 crystals diffract to 2.8,Å resolution and belong to space group P61/522, with unit-cell parameters a = b = 89.7, c = 136.7,Å. With two molecules in the asymmetric unit, the solvent content is 60% (VM = 3.1,Å3,Da,1). [source] Preliminary crystallographic study of Thermus aquaticus glycerol kinaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 7 2001Hua-Shan Huang Glycerol kinase (GlpK) is an important enzyme which catalyzes the rate-limiting step in a central biochemical pathway involving glycerol metabolism. GlpK from the thermophile Thermus aquaticus has been overexpressed in glpK -deficient Escherichia coli and crystallized by the hanging-drop method. The crystal belongs to the cubic space group I23, with unit-cell parameters a = b = c = 163.94,(3),Å. Native data were collected to 2.87,Å resolution on a Cu,K, rotating-anode X-ray source. [source] Crystallization and preliminary X-ray diffraction analysis of a rat biliverdin reductaseACTA CRYSTALLOGRAPHICA SECTION D, Issue 9 2000Danyu Sun Biliverdin reductase (BVR) catalyzes the final step of haem degradation and converts biliverdin to bilirubin using NAD(P)H as an electron donor. This paper deals with the first crystallization and preliminary crystallographic study of recombinant rat BVR expressed in Escherichia coli. Crystals of BVR were obtained by the sitting-drop vapour-diffusion method. Using synchrotron radiation at station BL44B2 of SPring-8, Japan, BVR diffraction data were collected to 1.6,Å resolution. Crystals belong to the orthorhombic space group P212121, with unit-cell parameters a = 58.89, b = 70.41, c = 87.76,Å. The complete determination of the crystallographic structure is currently in progress using MAD (multiwavelength anomalous diffraction) data from an Ir-derivative crystal. [source] Crystallization and preliminary crystallographic study of triple-helical DNAACTA CRYSTALLOGRAPHICA SECTION D, Issue 1 2000Zong-Jin Han Single crystals of d(CTCCTSCCGCGCG)·d(CGCGCGGAG) have been grown by the vapor-diffusion method using 2-methyl-2,4-pentanediol as a precipitant. The crystals are tetragonal, space group P42, with unit-cell parameters a = b = 53.8, c = 43.1,Å, and diffract to 1.8,Å resolution at a synchrotron X-ray beamline. In the crystal, the asymmetric unit contains one copy of the construct. The two halves of the structure are related by non-crystallographic twofold symmetry. These observations are consistent with the conclusion that the sequences of the 12-mer and 9-mer oligonucleotides form a duplex DNA at one end and a triplex DNA at the other end. [source] Preliminary crystallographic study of the Streptococcus agalactiae sortases, sortase A and sortase C1ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2010Baldeep Khare Sortases are cysteine transpeptidases that are essential for the assembly and anchoring of cell-surface adhesins in Gram-positive bacteria. In Streptococcus agalactiae (GBS), the pilin-specific sortase SrtC1 catalyzes the polymerization of pilins encoded by pilus island 1 (PI-1) and the housekeeping sortase SrtA is necessary for cell-wall anchoring of the resulting pilus polymers. These sortases are known to utilize different substrates for pilus polymerization and cell-wall anchoring; however, the structural correlates that dictate their substrate specificity have not yet been clearly defined. This report presents the expression, purification and crystallization of SrtC1 (SAG0647) and SrtA (SAG0961) from S. agalactiae strain 2603V/R. The GBS SrtC1 has been crystallized in three crystal forms and the GBS SrtA has been crystallized in one crystal form. [source] Crystallization and preliminary X-ray crystallographic study of GenX, a lysyl-tRNA synthetase paralogue from Escherichia coli, in complex with translation elongation factor PACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2010Tomomi Sumida GenX, a lysyl-tRNA synthetase paralogue from Escherichia coli, was overexpressed in E. coli, purified by three chromatographic steps and cocrystallized with a lysyl adenylate analogue (LysAMS) by the hanging-drop vapour-diffusion method using PEG 4000 as a precipitant. The GenX,LysAMS crystals belonged to the triclinic space group P1, with unit-cell parameters a = 54.80, b = 69.15, c = 94.08,Å, , = 95.47, , = 106.51, , = 90.46°, and diffracted to 1.9,Å resolution. Furthermore, GenX was cocrystallized with translation elongation factor P (EF-P), which is believed to be a putative substrate of GenX, and LysAMS using PEG 4000 and ammonium sulfate as precipitants. The GenX,EF-P,LysAMS crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 105.93, b = 102.96, c = 119.94,Å, , = 99.4°, and diffracted to 2.5,Å resolution. Structure determination of the E. coli GenX,LysAMS and GenX,EF-P,LysAMS complexes by molecular replacement was successful and structure refinements are now in progress. [source] Expression, crystallization and preliminary crystallographic study of mouse hepatitis virus (MHV) nucleocapsid protein C-terminal domainACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2010Xiaohang Tong Mouse hepatitis virus (MHV) belongs to the group II coronaviruses. The virus produces nine genes encoding 11 proteins that could be recognized as structural proteins and nonstructural proteins and are crucial for viral RNA synthesis. The nucleocapsid (N) protein, one of the structural proteins, interacts with the 30.4,kb virus genomic RNA to form the helical nucleocapsid and associates with the membrane glycoprotein via its C-terminus to stabilize virion assembly. Here, the expression and crystallization of the MHV nucleocapsid protein C-terminal domain are reported. The crystals diffracted to 2.20,Å resolution and belonged to space group P422, with unit-cell parameters a = 66.6, c = 50.8,Å. Assuming the presence of two molecules in the asymmetric unit, the solvent content is 43.0% (VM = 2.16,Å3,Da,1). [source] Expression, crystallization and preliminary X-ray crystallographic study of ethanolamine ammonia-lyase from Escherichia coliACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 6 2010Naoki Shibata Ethanolamine ammonia-lyase (EAL) catalyzes the adenosylcobalamin-dependent conversion of ethanolamine to acetaldehyde and ammonia. The wild-type enzyme shows a very low solubility. N-terminal truncation of the Escherichia coli EAL ,-subunit dramatically increases the solubility of the enzyme without altering its catalytic properties. Two deletion mutants of the enzyme [EAL(,,4,30) and EAL(,,4,43)] have been overexpressed, purified and crystallized using the sitting-drop vapour-diffusion method. Crystals of EAL(,,4,30) and EAL(,,4,43) diffracted to approximately 8.0 and 2.1,Å resolution, respectively. [source] Crystallization and preliminary X-ray studies of azoreductases from Bacillus sp.ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2010Azoreductases from Bacillus sp. B29 are NADH-dependent flavoenzymes which contain a flavin mononucleotide (FMN) as a prosthetic group and exist as homodimers composed of 23,kDa subunits. These enzymes catalyze the reductive degradation of various azo compounds by a ping-pong mechanism. In order to determine the structure,function relationship of the azo-dye reduction mechanism, an X-ray crystallographic study of azoreductases was performed. Selenomethionine-labelled AzrA (SeMet-AzrA) and AzrC were crystallized by the hanging-drop vapour-diffusion method. A crystal of SeMet-AzrA diffracted to 2.0,Å resolution and was determined to belong to space group P212121, with unit-cell parameters a = 56.9, b = 69.0, c = 105.4,Å. The native crystals of AzrC belonged to space group C2, with unit-cell parameters a = 192.0, b = 56.6, c = 105.5,Å, , = 115.7°, and diffracted to 2.21,Å resolution. [source] A preliminary crystallographic study of recombinant NicX, an Fe2+ -dependent 2,5-dihydroxypyridine dioxygenase from Pseudomonas putida KT2440ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2010José Ignacio Jiménez NicX from Pseudomonas putida KT2440 is an Fe2+ -dependent dioxygenase that is involved in the aerobic degradation of nicotinic acid. The enzyme converts 2,5-dihydroxypyridine to N -formylmaleamic acid when overexpressed in Escherichia coli. Biophysical characterization of NicX by analytical gel-filtration chromatography revealed that it behaves as an oligomeric assembly in solution, with an apparent molecular weight that is consistent with a hexameric species. NicX was crystallized by the hanging-drop vapour-diffusion method at 291,K. Diffraction data were collected to a resolution of 2.0,Å at the ESRF. The crystals most probably belong to the orthorhombic space group C222 or C2221. The estimated Matthews coefficient was 2.4,Å3,Da,1, corresponding to 50% solvent content, which is consistent with the presence of three protein molecules in the asymmetric unit. Analysis of the crystal data together with chromatographic results supports NicX being a hexameric assembly composed of two cyclic trimers. Currently, crystallization of recombinant selenomethionine-containing NicX is in progress. [source] Preliminary X-ray crystallographic study of the receptor-binding domain of the D/C mosaic neurotoxin from Clostridium botulinumACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2010Nipawan Nuemket Botulinum toxin (BoNT) from Clostridium botulinum OFD05, isolated from bovine botulism, is a D/C mosaic-type BoNT. BoNTs possess binding, translocation and catalytic domains. The BoNT/OFD05 binding domain exhibits significant sequence identity to BoNT/C, which requires a single ganglioside as a binding receptor on neuronal cells, while BoNT/A and BoNT/B require two receptors for specific binding. To determine the binding mechanism of BoNT/OFD05 and its ganglioside receptors on neuronal cells, recombinant BoNT/OFD05 receptor-binding domain has been expressed, purified and crystallized. Native and SeMet-derivative crystals showed X-ray diffraction to 2.8 and 3.1,Å resolution, respectively. The crystals belonged to space group P212121. [source] Crystallization and preliminary X-ray crystallographic study of 1-deoxy- d -xylulose 5-phosphate reductoisomerase from Plasmodium falciparumACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Tomonobu Umeda The nonmevalonate pathway of isoprenoid biosynthesis present in Plasmodium falciparum is known to be an effective target for antimalarial drugs. The second enzyme of the nonmevalonate pathway, 1-deoxy- d -xylulose 5-phosphate reductoisomerase (DXR), catalyzes the transformation of 1-deoxy- d -xylulose 5-phosphate (DXP) to 2- C -methyl- d -erythritol 4-phosphate (MEP). For crystallographic studies, DXR from the human malaria parasite P. falciparum (PfDXR) was overproduced in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method in the presence of NADPH. X-ray diffraction data to 1.85,Å resolution were collected from a monoclinic crystal form belonging to space group C2 with unit-cell parameters a = 168.89, b = 59.65, c = 86.58,Å, , = 117.8°. Structural analysis by molecular replacement is in progress. [source] Crystallization and preliminary X-ray crystallographic study of phosphoglucose isomerase from Plasmodium falciparumACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 3 2010Ken-ichi Aoki Phosphoglucose isomerase (PGI) is a key enzyme in glycolysis and glycogenesis that catalyses the interconversion of glucose 6-phosphate (G6P) and fructose 6-phosphate (F6P). For crystallographic studies, PGI from the human malaria parasite Plasmodium falciparum (PfPGI) was overproduced in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data to 1.5,Å resolution were collected from an orthorhombic crystal form belonging to space group P212121 with unit-cell parameters a = 103.3, b = 104.1, c = 114.6,Å. Structural analysis by molecular replacement is in progress. [source] Cloning, expression, purification, crystallization and preliminary X-ray crystallographic study of the putative SAICAR synthetase (PH0239) from Pyrococcus horikoshii OT3ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2010Kavyashree Manjunath The study of proteins involved in de novo biosynthesis of purine nucleotides is central in the development of antibiotics and anticancer drugs. In view of this, a protein from the hyperthermophile Pyrococcus horikoshii OT3 was isolated, purified and crystallized using the microbatch method. Its primary structure was found to be similar to that of SAICAR synthetase, which catalyses the seventh step of de novo purine biosynthesis. A diffraction-quality crystal was obtained using Hampton Research Crystal Screen II condition No. 34, consisting of 0.05,M cadmium sulfate hydrate, 0.1,M HEPES buffer pH 7.5 and 1.0,M sodium acetate trihydrate, with 40%(v/v) 1,4-butanediol as an additive. The crystal belonged to space group P31, with unit-cell parameters a = b = 95.62, c = 149.13,Å. Assuming the presence of a hexamer in the asymmetric unit resulted in a Matthews coefficient (VM) of 2.3,Å3,Da,1, corresponding to a solvent content of about 46%. A detailed study of this protein will yield insights into structural stability at high temperatures and should be highly relevant to the development of antibiotics and anticancer drugs targeting the biosynthesis of purine nucleotides. [source] Purification, crystallization and preliminary crystallographic study of haemoglobin from camel (Camelus dromedarius): a high oxygen-affinity lowland speciesACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2009M. Balasubramanian Haemoglobin is a prototypical allosteric protein that is mainly involved in the transportation of oxygen from the lungs to tissues and of carbon dioxide back to the lungs in an intrinsically coordinated manner to maintain the viability of cells. Haemoglobin from Camelus dromedarius provides an interesting case study of adaptation to life in deserts at extremely high temperatures. An ambition to unravel the integrated structural and functional aspects of the casual survival of this animal at high temperatures led us to specifically work on this problem. The present work reports the preliminary crystallographic study of camel haemoglobin. Camel blood was collected and the haemoglobin was purified by anion-exchange chromatography and crystallized using the hanging-drop vapour-diffusion method under buffered high salt concentration using PEG 3350 as a precipitant. Intensity data were collected using a MAR 345 dtb image-plate detector system. Camel haemoglobin crystallized in the monoclinic space group P21, with one whole biological molecule (,2,2) in the asymmetric unit and unit-cell parameters a = 52.759, b = 116.782, c = 52.807,Å, , = 120.07°. [source] Preliminary joint neutron and X-ray crystallographic study of human carbonic anhydrase IIACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2009S. Z. Fisher Carbonic anhydrases catalyze the interconversion of CO2 to HCO3,, with a subsequent proton-transfer (PT) step. PT proceeds via a proposed hydrogen-bonded water network in the active-site cavity that is stabilized by several hydrophilic residues. A joint X-ray and neutron crystallographic study has been initiated to determine the specific water network and the protonation states of the hydrophilic residues that coordinate it in human carbonic anhydrase II. Time-of-flight neutron crystallographic data have been collected from a large (,1.2,mm3) hydrogen/deuterium-exchanged crystal to 2.4,Å resolution and X-ray crystallographic data have been collected from a similar but smaller crystal to 1.5,Å resolution. Obtaining good-quality neutron data will contribute to the understanding of the catalytic mechanisms that utilize water networks for PT in protein environments. [source] | |||||||||||||||||||||||||