Conformational distortions from local symmetry in cyclic and acyclic compounds: Crystallographic data analysis of C3CZCC3 fragments (Z = C, P, Si, N, S, O).

2Ch–2N square and hexagon interactions were extensively investigated by the combination of crystallographic data analysis and computational approaches.

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Expression, crystallization and preliminary crystallographic data analysis of PigI, a putativeL-prolyl-AMP ligase from the prodigiosin synthetic pathway inSerratia

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x14005780 ◽

2014 ◽

Vol 70 (5) ◽

pp. 624-627 ◽

Cited By ~ 1

Author(s):

Ning Han ◽

Tingting Ran ◽

Xiangdi Lou ◽

Yanyan Gao ◽

Jianhua He ◽

...

Keyword(s):

Data Analysis ◽

Catalytic Mechanism ◽

Unit Cell ◽

Crystallographic Data ◽

Biosynthesis Pathway ◽

Red Pigment ◽

Asymmetric Unit ◽

Unit Cell Parameters ◽

Solvent Content ◽

Cell Parameters

Prodigiosin, a member of the prodiginines, is a tripyrrole red pigment synthesized bySerratiaand some other microbes. A bifurcated biosynthesis pathway of prodigiosin has been proposed inSerratiain which MBC (4-methoxy-2,2′-bipyrrole-5-carbaldehyde) and MAP (2-methyl-3-N-amyl-pyrrole) are synthesized separately and then condensed by PigC to form prodigiosin. The first step for the synthesis of MBC is the activation of L-proline by PigI, but its catalytic mechanism has remained elusive. To elucidate its mechanism, recombinant PigI was purified and crystallized. Crystals obtained by the sitting-drop method belonged to space groupP1 and diffracted to 2.0 Å resolution, with unit-cell parametersa= 51.2,b= 62.8,c= 91.3 Å, α = 105.1, β = 90.1, γ = 92.2°. Matthews coefficient analysis suggested two molecules in the asymmetric unit, with aVMof 2.6 Å3 Da−1and a solvent content of 52.69%.

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Microchemical imaging in biomedical research

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100130225 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1118-1119

Author(s):

P. Ingram

Keyword(s):

Data Analysis ◽

Electron Probe ◽

The Other ◽

X Ray ◽

Cell Element ◽

Physiological Information ◽

Functional States ◽

Elemental Maps ◽

Electron Energy Loss ◽

Secondary Ion

It is well established that unique physiological information can be obtained by rapidly freezing cells in various functional states and analyzing the cell element content and distribution by electron probe x-ray microanalysis. (The other techniques of microanalysis that are amenable to imaging, such as electron energy loss spectroscopy, secondary ion mass spectroscopy, particle induced x-ray emission etc., are not addressed in this tutorial.) However, the usual processes of data acquisition are labor intensive and lengthy, requiring that x-ray counts be collected from individually selected regions of each cell in question and that data analysis be performed subsequent to data collection. A judicious combination of quantitative elemental maps and static raster probes adds not only an additional overall perception of what is occurring during a particular biological manipulation or event, but substantially increases data productivity. Recent advances in microcomputer instrumentation and software have made readily feasible the acquisition and processing of digital quantitative x-ray maps of one to several cells.

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ELNES of Iron Compounds

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100133734 ◽

1990 ◽

Vol 48 (2) ◽

pp. 28-29

Author(s):

Hiroki Kurata ◽

Kazuhiro Nagai ◽

Seiji Isoda ◽

Takashi Kobayashi

Keyword(s):

Energy Loss ◽

Metal Ions ◽

Energy Resolution ◽

Transition Metal Oxides ◽

Local Symmetry ◽

Iron Compounds ◽

Fine Structures ◽

Electron Energy Loss ◽

Fe Ions ◽

Electron Energy Loss Spectra

Electron energy loss spectra of transition metal oxides, which show various fine structures in inner shell edges, have been extensively studied. These structures and their positions are related to the oxidation state of metal ions. In this sence an influence of anions coordinated with the metal ions is very interesting. In the present work, we have investigated the energy loss near-edge structures (ELNES) of some iron compounds, i.e. oxides, chlorides, fluorides and potassium cyanides. In these compounds, Fe ions (Fe2+ or Fe3+) are octahedrally surrounded by six ligand anions and this means that the local symmetry around each iron is almost isotropic.EELS spectra were obtained using a JEM-2000FX with a Gatan Model-666 PEELS. The energy resolution was about leV which was mainly due to the energy spread of LaB6 -filament. The threshole energies of each edges were measured using a voltage scan module which was calibrated by setting the Ni L3 peak in NiO to an energy value of 853 eV.

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