scholarly journals Molecular Genetic and Crystal Structural Analysis of 1-(4-Hydroxyphenyl)-Ethanol Dehydrogenase from ‘Aromatoleum aromaticum' EbN1

2015 ◽  
Vol 25 (5) ◽  
pp. 327-339 ◽  
Author(s):  
Imke Büsing ◽  
H. Wolfgang Höffken ◽  
Michael Breuer ◽  
Lars Wöhlbrand ◽  
Bernhard Hauer ◽  
...  
Keyword(s):  
Anaerobic Degradation ◽  
Ethanol Oxidation ◽  
Molecular Genetic ◽  
Reaction Step ◽  
Structural Determinants ◽  
X Ray ◽  
Short Chain Alcohol ◽  
Ethanol Dehydrogenase ◽  
Crystal Structural

The dehydrogenation of 1-(4-hydroxyphenyl)-ethanol to 4-hydroxyacetophenone represents the second reaction step during anaerobic degradation of <i>p</i>-ethylphenol in the denitrifying bacterium ‘<i>Aromatoleum aromaticum</i>' EbN1. Previous proteogenomic studies identified two different proteins (ChnA and EbA309) as possible candidates for catalyzing this reaction [Wöhlbrand et al: J Bacteriol 2008;190:5699-5709]. Physiological-molecular characterization of newly generated unmarked <i>in-frame</i> deletion and complementation mutants allowed defining ChnA (renamed here as Hped) as the enzyme responsible for 1-(4-hydroxyphenyl)-ethanol oxidation. Hped [1-(4-hydroxyphenyl)-ethanol dehydrogenase] belongs to the ‘classical' family within the short-chain alcohol dehydrogenase/reductase (SDR) superfamily. Hped was overproduced in <i>Escherichia coli</i>, purified and crystallized. The X-ray structures of the apo- and NAD<sup>+</sup>-soaked form were resolved at 1.5 and 1.1 Å, respectively, and revealed Hped as a typical homotetrameric SDR. Modeling of the substrate 4-hydroxyacetophenone (reductive direction of Hped) into the active site revealed the structural determinants of the strict <i>(R)</i>-specificity of Hped (Phe<sup>187</sup>), contrasting the <i>(S)</i>-specificity of previously reported 1-phenylethanol dehydrogenase (Ped; Tyr<sup>93</sup>) from strain EbN1 [Höffken et al: Biochemistry 2006;45:82-93].

Synthesis, crystal structure and properties of a 2-D Cd(II) coordination polymer based on ferrocenecarboxylate and 4,4′-bipyridine ligands

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Kai-Long Zhong ◽  
Jing Quan ◽  
Xian-Xiao Pan ◽  
Wei Song ◽  
Bing-Feng Li
Keyword(s):  
Coordination Polymer ◽  
Gravimetric Analysis ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Carboxylate Oxygen ◽  
Oxygen Chain ◽  
Crystal Structural

Abstract A new cadmium(II)-based coordination polymer [Cd3(FcCOO)6(4,4′-bipy)(H2O)2] n (FcCOO = ferrocenecarboxylato and 4,4′-bipy = 4,4′-bipyridine) has been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The results of a crystal structural analysis has revealed that the title compound consists of two crystallographically unique CdII centers, one in a general position with a five-coordinated and one on an inversion center with a six-coordinated environment. The CdII centers are connected by FcCOO− units to form a metal carboxylate oxygen chain extending parallel to the [100] direction while the 4,4′-bipy ligands further act as bridging linkers of the CdII centers resulting in a layered polymer. In addition, an X-ray powder diffraction and thermal gravimetric analysis and a cyclo-voltammetric characterization of the complex have also been carried out.

Structural Characterization of a Cage Ligand Fragmentation Reaction

1994 ◽  
Vol 47 (1) ◽  
pp. 181 ◽  
Author(s):  
JM Harrowfield ◽  
AM Sargeson ◽  
BW Skelton ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Room Temperature ◽  
Fragmentation Reaction ◽  
X Ray ◽  
Nitrogen Donor ◽  
Crystal Structural

The room temperature X-ray single-crystal structural characterization of a protonated copper(II) complex of a ligand artefact, L′, of L = N-Me6sar (described in an accompanying paper) is recorded, the new ligand L′ being generated formally by elimination of a CH2CH2 bridge between a pair of nitrogen donor atoms of L. The complex, [ ClCu (H2L′) (ClO4)3.2H2O, is orthorhombic, Pccn , a 22.528(7), b 10.544(3), c 13.748(6) Ǻ, Z = 4 formula units, R being 0.053 for 1133 independent 'observed' [I > 3σ(I)] reflections. The cation, containing five-coordinate square-pyramidal ClCuN4 copper, is disposed with the Cu- Cl bond [2.458(3)Ǻ] lying on a crystallographic 2 axis; Cu-N distances are 2.094(8) and 2.093(8)Ǻ.

Synthesis and Crystal Structural Characterization of Mixed-Ligand Cadmium(II) Complexes of 3-Triphenylphosphoniopropanoate and N ,N ,N′ ,N′-Tetramethylethylenediamine (tmen)

1997 ◽  
Vol 50 (1) ◽  
pp. 79 ◽  
Author(s):  
Song-Lin Li ◽  
Thomas C. W. Mak
Keyword(s):  
Nitrogen Atom ◽  
Mixed Ligand ◽  
The Other ◽  
Coordination Environment ◽  
Space Group ◽  
X Ray ◽  
Distorted Octahedral ◽  
Crystal Structural ◽  
Distorted Octahedral Coordination Environment

Two mixed-ligand cadmium(II) complexes have been synthesized from the reaction of 3-triphenyl- phosphoniopropanoate, Ph3P+ (CH2)2CO2¯, and Me2N(CH2)2NMe2 (abbreviated as tmen) with Cd(ClO4)2.x H2O and CdI2, and structurally characterized by single-crystal X-ray analysis: [Cd { Ph3P(CH2)2CO2 } 2(tmen)(H2O)] (ClO4)2.2H2O (1), space group P -1 with a 13·461(5), b 13·694(5), c 18·229(4) Å, α 92·34(2), β 110·51(2), γ 117·44(2)° and Z 2; [CdI2 { Ph3P(CH2)2CO2 } (tmen)] (2), space group P 21/c with a 16·768(6), b 11·741(3), c 16·915(5) Å, β 112·28(2)° and Z 4. In complex (1), the cadmium(II) atom is in a distorted pentagonal bipyramidal environment with two chelated betaine ligands and one nitrogen atom of the chelated tmen ligand defining the equatorial plane, and an aqua ligand and the other tmen nitrogen atom occupying the axial positions. One of the betaine ligands acts in the symmetric and the other in the asymmetric chelate mode. In complex (2), the distorted octahedral coordination environment about the cadmium(II) atom involves a chelated tmen ligand, an asymmetrically chelated betaine ligand, and two cis-related iodo ligands.

Synthesis and Characterization of Nanocrystalline SnO2 Powder

2011 ◽  
Vol 675-677 ◽  
pp. 267-270
Author(s):  
Shi Min Liu ◽  
Wan Yu Ding ◽  
Wei Wei Jiang ◽  
Wei Ping Chai
Keyword(s):  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Direct Precipitation ◽  
Transmission Electron ◽  
Crystal Structural ◽  
Sno2 Powder ◽  
Direct Precipitation Method

Nanocrystalline SnO2 powder has been synthesized via direct precipitation method starting from Sn, HNO3, HCl, and NH4OH. Thermal properties, crystal structural and morphological properties of the precursor and SnO2 powder were investigated using simultaneous thermogravimetry-differential thermal analysis, X-ray diffraction and transmission electron microscopy. The results indicated that the precursor was SnO2 rather than Sn(OH)2 or Sn(OH)4. On the basis of the precursor, well crystallized SnO2 powder with 4-5 nm in diameter was obtained, after calcined at 350 °C for 2 h.

scholarly journals HDX-MS reveals structural determinants for RORγ hyperactivation by synthetic agonists

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Timothy S Strutzenberg ◽  
Ruben D Garcia-Ordonez ◽  
Scott J Novick ◽  
HaJeung Park ◽  
Mi Ra Chang ◽  
...  
Keyword(s):  
Small Molecules ◽  
Structural Dynamics ◽  
Site Directed Mutagenesis ◽  
Chemical Probes ◽  
Structural Determinants ◽  
X Ray ◽  
Synthetic Ligand ◽  
Hdx Ms

Members of the nuclear receptor (NR) superfamily regulate both physiological and pathophysiological processes ranging from development and metabolism to inflammation and cancer. Synthetic small molecules targeting NRs are often deployed as therapeutics to correct aberrant NR signaling or as chemical probes to explore the role of the receptor in physiology. Nearly half of NRs do not have specific cognate ligands (termed orphan NRs) and it’s unclear if they possess ligand dependent activities. Here we demonstrate that ligand-dependent action of the orphan RORγ can be defined by selectively disrupting putative endogenous—but not synthetic—ligand binding. Furthermore, the characterization of a library of RORγ modulators reveals that structural dynamics of the receptor assessed by HDX-MS correlate with activity in biochemical and cell-based assays. These findings, corroborated with X-ray co-crystallography and site-directed mutagenesis, collectively reveal the structural determinants of RORγ activation, which is critical for designing RORγ agonists for cancer immunotherapy.

X-ray single-crystal structural characterization of Na2MgSiO4 with cristobalite-type structure synthesised at 22 GPa and 1800 °C

2018 ◽  
Vol 30 (3) ◽  
pp. 485-489 ◽  
Author(s):  
Ekaterina A. Sirotkina ◽  
Luca Bindi ◽  
Andrey V. Bobrov ◽  
Anastasia Tamarova ◽  
Dmitry Yu. Pushcharovsky ◽  
...  
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Type Structure ◽  
X Ray ◽  
Crystal Structural
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