Australian Synchrotron Research Articles

Abstract 3938: Localized synchrotron radiation affects serum cytokine levels and modulates gene expression in irradiated mouse skin and in skin distant from the irradiated site

Abstract Synchrotron radiation has great potential to improve cancer radiotherapy, a major cancer treatment received by about 50% cancer patients annually. A new synchrotron-based modality, microbeam radiotherapy (MRT), has shown promise for cancer treatment. MRT utilizes high intensity X-rays collimated to planar microbeams 25 μm-wide and with 200 μm period. MRT effectively ablates tumours but causes less damage to normal tissues compared to conventional broadbeam (BB) radiotherapy techniques. Little is known about the mechanisms underlying this remarkable result. We initiated a study of systemic (“abscopal”, “distant bystander”) effects1,2 of MRT and BB irradiation in C57BL/6J mice. Skin areas (2x2 and 8x8 mm) were irradiated with 10 or 40 Gy, and blood and skin samples were collected at 24 and 96 hours post-irradiation. Serum levels of pro-inflammatory cytokines known to be induced by radiation or to mediate the bystander effect, were measured. In parallel, gene expression was measured in irradiated and non-irradiated skin using real time PCR. Statistically significant changes were identified for known radiation responsive genes in both targeted and non-targeted dermal tissue after both BB and MRT treatments. Down-regulation of some genes in distant skin that were up-regulated at the site of irradiation were identified in an apparent contrasting response between these two sets of tissues. Also, the expression for some genes showed differences between MRT and BB-treated mice. MRT-specific bystander responses were also observed in distant tissue, including gene expression of TP53 for which the protein product has a fundamental role in cell fate. Levels of various cytokines in the serum were also altered in response to both BB and MRT. In some cases, the cytokine response was different for MRT compared to BB-treated samples which could potentially explain the benefits of MRT. These results advance the understanding of the biological responses to synchrotron-generated radiation and provide a potential mechanism for MRT.

Chemical Crystallography at the Australian Synchrotron MX Beamlines

The Macromolecular Crystallography (MX) Beamlines at the Australian Synchrotron collect data on protein samples (PX) and chemical samples (CX). This broad range of sample types requires us to consider a number of experimental and data processing considerations. Protein samples have very large unit cells but diffract weakly, the chemical samples on the other hand have very small unit cell and diffract comparatively strongly. From an experimental point of view, this requires substantially different geometrical considerations which can be handled by changing the energy of the monochromated X-rays and detector distance. Another consideration is detector type, the detectors at the MX beamlines are from the Area Detector Systems Corporation (ADSC) and they have generally been used for PX data collections. This has lead to investigation regarding high incidence angle phosphor thickness corrections. As the detectors have mainly been used for PX work, the software for sample handling has also been developed with PX considerations rather than CX. For example, the software for space group determinations is set my default to assumes that your space group is only ever one of the 65 space groups that don't contain mirror, inversion or glide operations. Another area of interest is the way data scaling is handled. The data is often scaled with PX data for a number of reasons, with the most common scaling of data is due t the prevalence of radiation damage to the samples. By contrast the most common form of scaling for CX data is for sample anisotropy in strong absorbers. A discussion of the challenges faced for the chemical crystallography experiments at the Australian Synchrotron will be presented.

Thermal expansion of monoclinic natrojarosite

Jarosites and related minerals are of great interest to a range of mineral processing and research applications. In some industrial settings jarosite formation is encouraged; for example to aid the removal of iron species from solutions in hydrometallurgical processes. In other environments such as bioleaching, jarosite formation can hinder the process by creating a kinetic barrier, in the form of a passivation layer, to the desired reaction. Jarosites are a major component of acidic soils and are present in significant amounts in acid mine drainage environments. There has been a recent resurgence in interest in jarosite minerals since their detection on Mars by the MER rover Opportunity. In this context, the presence of jarosite has been recognised as a likely indicator of the presence of water on Mars in the past. It is hoped that study of their formation mechanisms, stability and thermoelastic properties will provide insight into the environmental history of Mars as well as informing terrestrial industrial concerns. To this end we are engaged in a program to study jarosites and their formation and stability behaviour over a range of conditions. This contribution describes in situ powder diffraction experiments to determine the thermal expansion of a deuterated natrojarosite. Data were collected on the HRPD beamline at the ISIS spallation source where the natrojarosite sample was heated from 10–700K, and at the powder diffraction beamline at the Australian synchrotron where the sample was heated from 80-700K. Isothermal neutron and synchrotron datasets were refined simultaneously. Analysis of the lattice parameter variation with temperature shows that all cell edges increase smoothly to ~500 K where there is a discontinuity. This discontinuity represents the initially non-stoichiometric monoclinic jarosite converting to a stoichiometric, rhombohedral phase, shortly after which FeOHSO4 peaks become visible. Thermal expansion coefficients have been fitted from 10-470K and show that there is most variation in the monoclinic c-axis. This direction is normal to the layers of sulphate tetrahedra and iron octahedra within the jarosite structure and contains more flexible hydrogen bond linkages which more easily accommodate expansion than the more rigid polyhedra. Details of the combined neutron-synchrotron diffraction approach will also be discussed.

Structural characterisation of retromer complexes

Retromer is a peripheral membrane protein complex that plays a critical role in a broad range of physiological, developmental and pathological processes including Wnt signalling, toxin transport and amyloid production in Alzheimer's disease. The classical mammalian retromer complex consists of a core heterotrimeric cargo recognition sub-complex (VPS26, VPS29 and VPS35) associated with a dimer of proteins from the SNX–BAR sorting nexin family that drives membrane deformation and tubulation. By recruiting the cargo-selective sub-complex to the forming tubules, the SNX–BAR coat complex mediates the retrograde transport of proteins from endosomes to the trans-Golgi network. Recent studies, however, have highlighted the molecular and functional diversity of retromer and the identification of new interacting proteins has revealed that the role of retromer extends to aspects of endosome-to-plasma membrane sorting and regulation of signalling events. Emerging evidence indicates that cargo specificity is mediated by specific sorting nexins. These include SNX3, involved in the trafficking of the Wntless/MIG-14 protein, and SNX27, a PX-FERM protein that mediates the retrieval of the β2-adrenergic receptor.Using the MX and SAXS/WAXS beamlines at the Australian Synchrotron, we have acquired crystallographic and small angle scattering data to determine how the core cargo recognition sub-complex assembles and to characterise the retromer-associated sorting nexins. We are using this structural information in combination with biochemical and biological studies in a synergistic approach to understand retromer-mediated endosomal protein sorting and how this fascinating protein complex contributes to a diverse set of cellular processes. The retromer complex is conserved across all eukaryotes. We are also currently exploring the structure of these proteins in the thermophilic fungus Chaetomium thermophilum and initial crystallisation experiments have produced some promising results.

Rubrerythrin from Trichomonas vaginalis- structural insights into its mechanism of action

Trichomoniasis is a common STD with an estimated prevalence of 4 million infections in the United States. The organism that causes trichomoniasis, Trichomonas vaginalis, is essentially anaerobic and contains proteins such as peroxidases that help detoxify reactive oxygen species in its environment. A unique non-heme peroxidase called rubrerythrin, found in this organism, is homologous to bacterial peroxidases, and is markedly upregulated during oxidative stress. It could represent a target for therapeutic intervention given the importance of an anaerobic environment for this organism's survival. Using protein crystallography, we have determined the three-dimensional structure of two forms of this enzyme, the wild-type rubrerythrin which is reddish in colour and a mutant protein, T48A, which is purple. The genes were cloned and expressed in E. coli and purified using liquid chromatography. Crystallization was carried out using vapor diffusion methods. Following optimization, data sets were collected to 2.2Å at the Australian Synchrotron in Melbourne. The phase problem was solved using molecular replacement. Subsequent refinement in Space Group P21212 has yielded a structure with an Rwork/Rfree of 20.6 and 27.3 respectively. The resulting rubrerythrin structure is a dimer of four-helix bundles each containing two metal centers in a geometry and fold very similar to bacterial orthologs. Kinetic studies indicate that it can function as an efficient peroxidase, but only if all sites are occupied by iron. The key to the purple color of the T48A mutant rubrerythrin appears to involve the serendipitous formation of a charge-transfer complex involving the diiron site and a tyrosine, which is facilitated by this mutation. This is the first structure reported of a eukaryotic non-haem iron peroxidase. It is a potentially important virulence factor in T. vaginalis and will serve as a basis for further work to characterize its function within the organism.

Battery research using synchrotron powder X-ray diffraction

Research and development of rechargeable batteries is critical to meet the worldwide demand for clean and sustainable energy collection and storage. A vital part of this research is to get clear understanding of how the crystal structures of electrode materials affect the the resulting properties of the batteries. As structural changes in both the anode and cathode materials play an important role in overall battery performance, synchrotron powder X-ray diffraction (PXRD), with high beam flux and resolution, is an extremely useful tool for studying the battery both in-situ and ex-situ. Several simple in-situ cell designs have been designed for synchrotron PXRD measurement. The cell is available for researchers in the field of battery research. The effectiveness and simplicity of the cell design have been demonstrated at Powder Diffraction Beamline at Australian Synchrotron for several user groups. Case studies of analysis of the lithium insertion reaction for Li0.18Sr0.66Ti0.5Nb0.5O3 defect perovskite [1], crystal structure of Li4Ti5O12–xBrx electrode material [2] and LiNi1/3Mn1/3Co1/3O2 (NMC) as a new synthesized cathode material [3] will be discussed, respectively.

Wing wettability of Odonata species as a function of quantity of epicuticular waxes

Dragonflies have gained much attention due to their sophisticated wing surface structure, and their associated superhydrophobic, self-cleaning and bactericidal properties. In this work, we compared and contrasted the chemical composition and surface morphology of the wing membranes of four species of dragonfly and damselfly from the Odonata family collected in 1970s (Diplacodes melanopsis and Xanthagrion erythroneurum) and 2011 (Diplacodes bipunctata, and Ischnura heterosticta). Diplacodes species are dragonflies, whilst Xanthagrion and Ischnura are damselflies. Fourier-transform infrared spectroscopy data obtained from the Australian Synchrotron were used to classify the fundamental components of all four of the insect species’ wings. The spectra of all species were dominated by CH stretching, amide I and amide II and OH stretch absorbance indicating the presence of a similar membrane composition of chitin, protein and wax in all four species. Although the samples were collected 40 years apart, there was no evidence of degradation having taken place during this time. Despite the overall similarities in spectral profile, species-specific differences were observed, most notably in the intensity of the νCH2 peaks, which in part reflected the amount of waxes present on the wings, which appeared to be different between individual species. The surface topography also contained minor differences in the diameter and the spacial distribution of its nanopillars. It is postulated that the differences in surface wettability of the wings could be attributed to these minor differences in surface chemistry and surface topography. For example, X. erythroneurum presented the highest water contact angle (WCA) of 160° whilst the D. melanopsis wings exhibited the lowest WCA (138°), and the wettability of their wings was found to directly correlate with the intensity of hydrocarbon peaks found in their respective IR specta.

Rovibrational constants of the ground and ν12 = 1 states of C2D4 by high-resolution synchrotron FTIR spectroscopy

The Fourier transform infrared (FTIR) absorption spectrum of the ν12 fundamental band of ethylene-d4 (C2D4) was recorded in the 1000–1150cm−1 region with a resolution of 0.00096cm−1 using the THz/far-infrared beamline of the Australian Synchrotron. Upper state (ν12=1) rovibrational constants consisting of three rotational constants and up to five quartic constants were improved by assigning and fitting 3950 rovibrational transitions using Watson’s A-reduced and S-reduced Hamiltonians in the Ir representation. The band centres of the unperturbed A-type ν12 band are found to be 1076.984958(14) cm−1 and 1076.984813(14) cm−1 for A-reduced and S-reduced Hamiltonians respectively. The present analysis, covering a wider wavenumber range and higher J and Kc values (up to 58) than previous studies, yielded upper state constants including the band centre which are more accurate than previously reported. The rms deviation of the upper state (ν12=1) fit is 0.00040cm−1 in the A-reduction and 0.00041cm−1 in the S-reduction. Improved ground state rovibrational constants were also determined from the fit of 3151 ground state combination differences (GSCD) from the presently-assigned transitions of the ν12 band of C2D4 using Watson’s A-reduced and S-reduced Hamiltonians in the Ir representation. The rms deviation of the GSCD fit is 0.00036cm−1 in the A-reduction and 0.00035cm−1 in the S-reduction. The ground state constants of C2D4 derived from the experimental GSCD fit are in good agreement with those from theoretical calculations using the B3LYP/cc-pVTZ, MP2/cc-pVTZ, and CSSD/cc-pVTZ levels, up to five quartic constants.

Qualitative spectroscopic characterization of the matrix–silane coupling agent interface across metal fibre reinforced ion exchange resin composite membranes

The characterization of novel metal reinforced electro-dialysis ion exchange membranes, for water desalination, by attenuated total reflectance Fourier transform infrared spectroscopy mapping is presented in this paper. The surface of the porous stainless steel fibre meshes was treated in order to enhance the amount of surface oxide groups and increase the material hydrophilicity. Then, the metal membranes were functionalized through a sol–gel reaction with silane coupling agents to enhance the affinity with the ion exchange resins and avoid premature metal oxidation due to redox reactions at the metal–polymer interface. Polished cross sections of the composite membranes embedded into an epoxy resin revealed interfaces between metallic frameworks and the silane layer at the interface with the ion exchange material. The morphology of the metal–polymer interface was investigated with scanning electron microscopy and Fourier transform infrared micro-spectroscopy. Fourier transform infrared mapping of the interfaces was performed using the attenuated total reflectance mode on the polished cross-sections at the Australian Synchrotron. The nature of the interface between the metal framework and the ion exchange resin was shown to be homogeneous and the coating thickness was found to be around 1μm determined by Fourier transform infrared micro-spectroscopy mapping. The impact of the coating on the properties of the membranes and their potential for water desalination by electro-dialysis are also discussed.

Gra ianite, MnBi2S4, a new mineral from the Baia Bihor skarn, Romania

The new mineral graţianite, MnBi 2 S 4 , is described from the Bǎia Bihor skarn deposit, Bihor County, Romania. Graţianite occurs as thin lamellae, intimately intergrown with cosalite and bismuthinite, or as flower-shaped blebs within chalcopyrite, where it is associated with cosalite and tetradymite. Graţianite displays weak to modest bireflectance in air and oil, respectively, and strong anisotropy. The mean empirical composition based on 20 electron probe microanalyses is: (Mn 0.541 Fe 0.319 Pb 0.070 Cu 0.040 Cd 0.009 Ag 0.001 ) S0.980 (Bi 1.975 Sb 0.018 ) S1.993 (S 4.008 Se 0.012 Te 0.007 ) S4.027 , corresponding to the ideal formula MnBi 2 S 4 . Graţianite crystallizes in the monoclinic system (space group C 2/ m ). Single-crystal X-ray studies of material extracted by the focused ion beam-scanning electron microscopy (FIB-SEM) technique, and carried out on the MX2 macromolecular beamline of the Australian Synchrotron determined the following cell dimensions: a = 12.6774(25) A, b = 3.9140(8) A, c = 14.7581(30) A, b = 115.31(3)°, V = 662.0(2) A 3 , and Z = 4. The six strongest X-ray reflections and their relative intensities are: 3.448 A (100), 2.731 A (77), 2.855 A (64), 3.637 A (55), 3.644 A (54), and 3.062 A (51). Graţianite is the monoclinic analog of berthierite (FeSb 2 S 4 ), garavellite [Fe(Bi,Sb) 2 S 4 ] and clerite [Mn(Sb,As) 2 S 4 ] (Nickel-Strunz class 02.HA.20). It is isostructural with synthetic sulfides and selenides in the MnBi 2 S 4 –MnSb 2 S 4 and MnBi 2 Se 4 –MnSb 2 Se 4 series, and with grumiplucite (HgBi 2 S 4 ) and kudriavite, [(Cd,Pb)Bi 2 S 4 ], 3 P members of the pavonite homologous series. The mineral is named for Graţian Cioflica (1927–2002), formerly Professor in Mineralogy and Ore Deposits at the University of Bucharest, Romania. The Baia Bihor skarn, like others within the same belt, is geochemically complex. The availability of Cu, Zn, and Pb, but also Ag, Bi, Mo, and B, as well as a wide range of minor elements, has created an environment allowing for crystallization of an unusually diverse range of discrete minerals. Graţianite is part of the peculiar associations of Bi–Pb-sulfosalts and Bi-chalcogenides that are genetically related to Au-enrichment. This study demonstrates the versatility of FIB-SEM techniques for in situ extraction of small volumes of well-characterized material, coupled with single-crystal X-ray analysis using synchrotron radiation, for the characterization of new minerals.

Maia X-ray fluorescence imaging: Capturing detail in complex natural samples

Motivated by the challenge of capturing complex hierarchical chemical detail in natural material from a wide range of applications, the Maia detector array and integrated realtime processor have been developed to acquire X-ray fluorescence images using X-ray Fluorescence Microscopy (XFM). Maia has been deployed initially at the XFM beamline at the Australian Synchrotron and more recently, demonstrating improvements in energy resolution, at the P06 beamline at Petra III in Germany. Maia captures fine detail in element images beyond 100 M pixels. It combines a large solid-angle annular energy-dispersive 384 detector array, stage encoder and flux counter inputs and dedicated FPGA-based real-time event processor with embedded spectral deconvolution. This enables high definition imaging and enhanced trace element sensitivity to capture complex trace element textures and place them in a detailed spatial context. Maia hardware and software methods provide per pixel correction for dwell, beam flux variation, dead-time and pileup, as well as off-line parallel processing for enhanced throughput. Methods have been developed for real-time display of deconvoluted SXRF element images, depth mapping of rare particles and the acquisition of 3D datasets for fluorescence tomography and XANES imaging using a spectral deconvolution method that tracks beam energy variation.

The multi-modal Australian ScienceS Imaging and Visualization Environment (MASSIVE) high performance computing infrastructure: applications in neuroscience and neuroinformatics research.

The Multi-modal Australian ScienceS Imaging and Visualization Environment (MASSIVE) is a national imaging and visualization facility established by Monash University, the Australian Synchrotron, the Commonwealth Scientific Industrial Research Organization (CSIRO), and the Victorian Partnership for Advanced Computing (VPAC), with funding from the National Computational Infrastructure and the Victorian Government. The MASSIVE facility provides hardware, software, and expertise to drive research in the biomedical sciences, particularly advanced brain imaging research using synchrotron x-ray and infrared imaging, functional and structural magnetic resonance imaging (MRI), x-ray computer tomography (CT), electron microscopy and optical microscopy. The development of MASSIVE has been based on best practice in system integration methodologies, frameworks, and architectures. The facility has: (i) integrated multiple different neuroimaging analysis software components, (ii) enabled cross-platform and cross-modality integration of neuroinformatics tools, and (iii) brought together neuroimaging databases and analysis workflows. MASSIVE is now operational as a nationally distributed and integrated facility for neuroinfomatics and brain imaging research.

IR Band Profiling of Dichlorodifluoromethane in the Greenhouse Window: High-Resolution FTIR Spectroscopy of ν2 and ν8

The IR spectrum of dichlorodifluoromethane (i.e., R12 or Freon-12) is central to its role as a major greenhouse contributor. In this study, high-resolution (0.000 96 cm(-1)) Fourier transform infrared spectra have been measured for R12 samples either cooled to around 150 K or at ambient temperature using facilities on the infrared beamline of the Australian Synchrotron. Over 14,000 lines of C(35)Cl2F2 and C(35)Cl(37)ClF2 were assigned to the b-type ν2 band centered around 668 cm(-1). For the c-type ν8 band at 1161 cm(-1), over 10,000 lines were assigned to the two isotopologues. Rovibrational fits resulted in upper state constants for all these band systems. Localized avoided crossings in the ν8 system of C(35)Cl2F2, resulting from both a direct b-axis Coriolis interaction with ν3 + ν4 + ν7 and an indirect interaction with ν3 + ν4 + ν9, were treated. An improved set of ground state constants for C(35)Cl(37)ClF2 was obtained by a combined fit of IR ground state combination differences and previously published millimeter wave lines. Together these new sets of constants allow for accurate prediction of these bands and direct comparison with satellite data to enable accurate quantification.

Quantified, whole section trace element mapping of carbonaceous chondrites by Synchrotron X-ray Fluorescence Microscopy: 1. CV meteorites

We present the application of a new synchrotron-based technique for rapid mapping of trace element distributions across large areas of the CV3 meteorites Allende and Vigarano. This technique utilizes the Australian Synchrotron X-ray Fluorescence Microscopy (XFM) beam line with its custom designed and built X-ray detector array called Maia. XFM with Maia allows data to be collected using a 2μm spot size at very low dwell times (∼0.1–0.5ms), resulting in maps of entire thin sections in ∼5h. Maia is an energy dispersive detector system with a large collection solid-angle, which allows full spectral acquisition and high sensitivity. Hence, there is no need to constrain the elements of interest a priori.We collected whole section maps (∼2cm×1cm) from 3 thick sections of Allende and a single map (2cm×1.5cm) from a thick section of Vigarano. Our experimental conditions provide data for elements with 20⩽Z⩽40 (K-shell, Ca through Zr) and the L-emissions of Os, Ir, Pt, Au, and Pb. We illustrate the unique capabilities of this technique by presenting observations across myriad length scales, from the centimeter-scale down to the detection of sub-micrometer particles within these objects. Our initial results show the potential of this technique to help decipher spatial and textural variations in trace element chemistry between CAIs, chondrules, matrix, and other chondritic components. We also illustrate how these datasets can be applied to understanding both nebular and parent-body processes within meteorites.

Crystallization and preliminary X-ray diffraction analysis of the Fab portion of the Alzheimer's disease immunotherapy candidate bapineuzumab complexed with amyloid-β.

Bapineuzumab (AAB-001) and its derivative (AAB-003) are humanized versions of the anti-Aβ murine antibody 3D6 and are immunotherapy candidates in Alzheimer's disease. The common Fab fragment of these immunotherapies has been expressed, purified and crystallized in complex with β-amyloid peptides (residues 1-8 and 1-28). Diffraction data at high resolution were acquired from crystals of Fab-Aβ8 (2.0 Å) and Fab-Aβ28 (2.2 Å) complexes at the Australian Synchrotron. Both crystal forms belonged to the primitive orthorhombic space group P21221.

Feasibility study of propagation-based phase-contrast X-ray lung imaging on the Imaging and Medical beamline at the Australian Synchrotron

Propagation-based phase-contrast X-ray imaging (PB-PCXI) using synchrotron radiation has achieved high-resolution imaging of the lungs of small animals both in real time and in vivo. Current studies are applying such imaging techniques to lung disease models to aid in diagnosis and treatment development. At the Australian Synchrotron, the Imaging and Medical beamline (IMBL) is well equipped for PB-PCXI, combining high flux and coherence with a beam size sufficient to image large animals, such as sheep, due to a wiggler source and source-to-sample distances of over 137 m. This study aimed to measure the capabilities of PB-PCXI on IMBL for imaging small animal lungs to study lung disease. The feasibility of combining this technique with computed tomography for three-dimensional imaging and X-ray velocimetry for studies of airflow and non-invasive lung function testing was also investigated. Detailed analysis of the role of the effective source size and sample-to-detector distance on lung image contrast was undertaken as well as phase retrieval for sample volume analysis. Results showed that PB-PCXI of lung phantoms and mouse lungs produced high-contrast images, with successful computed tomography and velocimetry also being carried out, suggesting that live animal lung imaging will also be feasible at the IMBL.

Expression, purification, crystallization and preliminary X-ray analysis of the PaaI-like thioesterase SAV0944 from Staphylococcus aureus.

Staphylococcus aureus is the causative agent of many diseases, including meningitis, bacteraemia, pneumonia, food poisoning and toxic shock syndrome. Structural characterization of the PaaI-like thioesterase SAV0944 (SaPaaI) from S. aureus subsp. aureus Mu50 will aid in understanding its potential as a new therapeutic target by knowledge of its molecular details and cellular functions. Here, the recombinant expression, purification and crystallization of SaPaaI thioesterase from S. aureus are reported. This protein initially crystallized with the ligand coenzyme A using the hanging-drop vapour-diffusion technique with condition No. 40 of Crystal Screen from Hampton Research at 296 K. Optimal final conditions consisting of 24% PEG 4000, 100 mM sodium citrate pH 6.5, 12% 2-propanol gave single diffraction-quality crystals. These crystals diffracted to beyond 2 Å resolution at the Australian Synchrotron and belonged to space group P12(1)1, with unit-cell parameters a = 44.05, b = 89.05, c = 60.74 Å, β = 100.5°. Initial structure determination and refinement gave an R factor and R(free) of 17.3 and 22.0%, respectively, confirming a positive solution in obtaining phases using molecular replacement.

Kröhnkite-Type Na2Fe(SO4)2·2H2O as a Novel 3.25 V Insertion Compound for Na-Ion Batteries

Structural characterization X-ray diffraction patterns of polycrystalline powder samples were acquired by a Rigaku RINT-TTR III powder diffractometer equipped with a Cu-K radiation source (1 = 1.5405 A, 2 = 1.5443 A) operating at 50 kV and 300 mA. Typical scans were performed in the 2 range of 8~90 (step size = 0.028.s). Synchrotron X-ray diffraction (S-XRD) was conducted on the Powder Diffraction beamline at BL-10 of the Australian Synchrotron (Clayton, Australia) using radiation source of wavelength ( = 0.82550 A, calibrated against a LaB6 standard). For S-XRD, the powder samples were loaded inside glass capillaries ( = 0.3 mm) inside an Ar-filled glovebox. Rietveld analysis 1 of the SXRD data was performed using the GSAS program 2 with EXPGUI front-end 3 , taking into account the zero-shifts, scale factors, background corrections and pseudo-Voigt peak shape parameters.

Purification, crystallization and preliminary X-ray diffraction analysis of the N-acetyltransferase SAV0826 from Staphylococcus aureus.

Staphylococcus aureus is a prevalent microorganism that is capable of causing a wide range of infections and diseases. Several strains of this bacterial species have developed antibiotic resistance to methicillin and vancomycin, and higher death rates are still being reported each year owing to multidrug-resistant strains. Certain GCN5-related N-acetyltransferases (GNATs) exhibit a broad substrate range, including aminoglycosides, histones, other proteins and serotonin, and have been implicated in antibiotic drug resistance. Here, the expression, purification, crystallization and preliminary X-ray diffraction analysis of a GNAT from S. aureus (SaNAT) are reported. SaNAT was recombinantly expressed and crystallized by the hanging-drop vapour-diffusion method at 296 K, and the crystals diffracted to 1.7 Å resolution on the MX2 beamline at the Australian Synchrotron. The crystals belonged to space group P43212, with unit-cell parameters a = b = 84.86, c = 49.06 Å, α = β = γ = 90°. A single molecule is likely to be present in the asymmetric unit. A full structural and functional analysis is currently being undertaken to provide novel insights into the protein function, which in turn may provide a basis for drug design.

Crystallization and preliminary X-ray diffraction analysis of FabG from Yersinia pestis.

The type II fatty-acid biosynthesis pathway of bacteria provides enormous potential for antibacterial drug development owing to the structural differences between this and the type I fatty-acid biosynthesis system found in mammals. β-Ketoacyl-ACP reductase (FabG) is responsible for the reduction of the β-ketoacyl group linked to acyl carrier protein (ACP), and is essential for the formation of fatty acids and bacterial survival. Here, the cloning, expression, purification, crystallization and diffraction of FabG from Yersinia pestis (ypFabG), the highly virulent causative agent of plague, are reported. Recombinant FabG was expressed, purified to homogeneity and crystallized via the hanging-drop vapour-diffusion technique. Diffraction data were collected at the Australian Synchrotron to 2.30 Å resolution. The crystal displayed P2(1)2(1)2(1) symmetry, with unit-cell parameters a = 68.22, b = 98.68, c = 169.84 Å, and four ypFabG molecules in the asymmetric unit.