scholarly journals Chromohalobacter salixigens uronate dehydrogenase: Directed evolution for improved thermal stability and mutant CsUDH-inc X-ray crystal structure

2020 ◽  
Author(s):  
Kurt Wagschal ◽  
Victor J. Chan ◽  
Jose H. Pereira ◽  
Peter H. Zwart ◽  
Banumathi Sankaran
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Directed Evolution ◽  
X Ray ◽  
Uronate Dehydrogenase

Synthesis and structure of the ternary nitride Li6WN4

2005 ◽  
Vol 20 (1) ◽  
pp. 18-21 ◽  
Author(s):  
W. X. Yuan ◽  
J. W. Hu ◽  
Y. T. Song ◽  
W. J. Wang ◽  
Y. P. Xu
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
High Quality ◽  
X Ray ◽  
Cell Parameters ◽  
Tetragonal System ◽  
Ternary Nitride ◽  
Stability Measurements

The ternary nitridotungstate Li6WN4 has been synthesized via the solid state reaction of lithium subnitride, Li3N, with W under nitrogen. High quality X-ray powder diffraction data were collected for the crystal-structure determination. Li6WN4 crystallizes in the tetragonal system, space group P42∕nmc, with cell parameters a=6.6759(3) Å and c=4.9280(3) Å, Z=2. Preliminary thermal stability measurements of Li6WN4 show that it is sensitive to moisture, even at room temperature, and decomposes at high temperatures below 1000 °C under flowing nitrogen.

Synthesis and structural study from X-ray powder diffraction of Pb0.5Th2(PO4)3

1997 ◽  
Vol 12 (2) ◽  
pp. 76-80 ◽  
Author(s):  
A. El-Yacoubi ◽  
R. Brochu ◽  
A. Serghini ◽  
M. Louër ◽  
M. Alami Talbi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Structural Study ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Type ◽  
Powder Diffraction Data ◽  
Monoclinic Symmetry ◽  
X Ray ◽  
Thermal Stability Of

A new mixed lead thorium phosphate, Pb0.5Th2(PO4)3, has been isolated in the system PbO–ThO2–P2O5. Its crystal structure (monoclinic symmetry, a=17.459(1) Å, b=6.8451(4) Å, c=8.1438(5) Å, β=101.247(5)°, space group C2/c) has been determined from conventional monochromatic X-ray powder diffraction data. The structure is related to the MITh2(PO4)3 structure type. Lead atoms are located in the channels parallel to the c axis, out of the twofold axis for 0.97 Å, and are statistically distributed on a quarter of crystallographic positions. The thermal stability of this material is greater than that of the monazite-type compound PbTh(PO4)2.

scholarly journals Biochemical and Structural Characterization of the Subclass B1 Metallo-β-Lactamase VIM-4

2010 ◽  
Vol 55 (3) ◽  
pp. 1248-1255 ◽  
Author(s):  
Patricia Lassaux ◽  
Daouda A. K. Traoré ◽  
Elodie Loisel ◽  
Adrien Favier ◽  
Jean-Denis Docquier ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Thermal Stability ◽  
Pseudomonas Aeruginosa ◽  
Structural Characterization ◽  
Catalytic Efficiency ◽  
X Ray ◽  
Stabilizing Effect ◽  
Loop 2

ABSTRACTThe metallo-β-lactamase VIM-4, mainly found inPseudomonas aeruginosaorAcinetobacter baumannii, was produced inEscherichia coliand characterized by biochemical and X-ray techniques. A detailed kinetic study performed in the presence of Zn2+at concentrations ranging from 0.4 to 100 μM showed that VIM-4 exhibits a kinetic profile similar to the profiles of VIM-2 and VIM-1. However, VIM-4 is more active than VIM-1 against benzylpenicillin, cephalothin, nitrocefin, and imipenem and is less active than VIM-2 against ampicillin and meropenem. The crystal structure of the dizinc form of VIM-4 was solved at 1.9 Å. The sole difference between VIM-4 and VIM-1 is found at residue 228, which is Ser in VIM-1 and Arg in VIM-4. This substitution has a major impact on the VIM-4 catalytic efficiency compared to that of VIM-1. In contrast, the differences between VIM-2 and VIM-4 seem to be due to a different position of the flapping loop and two substitutions in loop 2. Study of the thermal stability and the activity of the holo- and apo-VIM-4 enzymes revealed that Zn2+ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure.

Crystal Structure, Thermoanalytical Properties and Infrared Spectra of Double Magnesium Selenates

1996 ◽  
Vol 61 (9) ◽  
pp. 1295-1306 ◽  
Author(s):  
Zdeněk Mička ◽  
Lucie Prokopová ◽  
Ivana Císařová ◽  
David Havlíček
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Salts ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Thermoanalytical Studies ◽  
Thermal Stability Of

Magnesium selenates double salts K2Mg(SeO4)2.6H2O, Rb2Mg(SeO4)2.6H2O, Cs2Mg(SeO4)2.6H2O, and (NH4)2Mg(SeO4)2.6H2O have been studied by means of X-ray diffraction methods, thermoanalytical methods, and infrared spectroscopy. The basic building units of these compounds are slightly deformed tetrahedra of selenate anions and octahedra of hexaaquamagnesium(II) cations interconnected by a system of hydrogen bonds. The investigation of IR spectra has been used in the discussion of X-ray diffraction results in the field of description of the hydrogen bond system and deformation of the basic polyhedra of selenate anion and hexaaquamagnesium cation. The thermoanalytical studies are used in evaluating the effects of hydrogen bonds and polarization influence of M+ cations on thermal stability of the compounds studied.

Lanthanide(III) complex metal-organic frameworks with a phenanthroline-carboxylate derivate and 2,5-thiophenedicarboxylate coligand: hydrothermal synthesis, crystal structure, and high thermostability

2018 ◽  
Vol 73 (5) ◽  
pp. 311-317
Author(s):  
Zhao Xu ◽  
Fengqin An ◽  
Xiaohui Ma ◽  
Huiliang Zhou ◽  
Weiming Song ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Metal Organic Frameworks ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Organic ◽  
3D Networks ◽  
Point Symbol

AbstractBased on 2-(4-carboxyphenyl)imidazo[4,5-f]-1,10-phenanthroline (HNCP) and 2,5-thiophenedicarboxylate (TDC2−) ligands, three new lanthanide-containing (Sm, Nd, and Pr) compounds, [Sm(NCP)(TDC)]n (1), [Nd(NCP)(TDC)]n·2n(H2O)0.5 (2), and [Pr(NCP)(TDC)]n·n(H2O)0.5 (3), have been synthesized using the hydrothermal method and structurally characterized using single-crystal X-ray diffraction. Structural analyses have revealed that compounds 1–3 are 3D isostructural metal-organic frameworks in which the [Ln2(COO)4] dimers can be regarded as 6-connecting nodes, and the TDC2− and NCP− ligands are simplified as connectors to achieve the double interspersed 3D networks with the point symbol {412·63}. Thermogravimetric analysis has illustrated that the rigid architecture contributes to superior thermal stability with a thermal decomposition temperature of more than 400°C for the resulting metal-organic frameworks.

scholarly journals A New 3D Coordination Polymer of Bismuth with Nicotinic AcidN-Oxide

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Farzin Marandi ◽  
Ingo Pantenburg ◽  
Gerd Meyer
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Coordination Polymer ◽  
Three Dimensional ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Thermal Stability Of

The new three-dimensional coordination polymer {[Bi(NNO)2(NO3)]·1.5H2O}n(1, NNO−= nicotinateN-oxide) was synthesized and characterized by elemental analysis, IR and1H-NMR spectroscopy, as well as single-crystal X-ray diffraction analysis.1crystallizes in the monoclinic space group C2/c. The crystal structure consists of a rectangular-shaped grid constructed with NNO linkers. Cavities of a diameter of 7.9–8.3 Å2are filled with disordered water molecules. The thermal stability of the compound was evaluated by thermogravimetric analysis.

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