High electrocatalytic activity of W18O49 nanowires for cobalt complex and ferrocenium redox mediators

RSC Advances ◽  
2014 ◽  
Vol 4 (79) ◽  
pp. 42190-42196 ◽  
Author(s):  
Huawei Zhou ◽  
Yantao Shi ◽  
Qingshun Dong ◽  
Liang Wang ◽  
Hong Zhang ◽  
...  
Keyword(s):  
Electrocatalytic Activity ◽  
Rational Design ◽  
Catalytic Properties ◽  
Cobalt Complex ◽  
Redox Mediators ◽  
Catalytic Processes ◽  
The Relationship

Understanding the relationship between the surface of electrocatalysts and the catalytic properties of different redox mediators is beneficial to the rational design of efficient catalysts for use in practical catalytic processes.

scholarly journals Cryo-EM structure of mycobacterial cytochrome bd reveals two oxygen access channels

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Weiwei Wang ◽  
Yan Gao ◽  
Yanting Tang ◽  
Xiaoting Zhou ◽  
Yuezheng Lai ◽  
...  
Keyword(s):  
Rational Design ◽  
Pathogenic Bacteria ◽  
Structural Topology ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
Cytochrome Bd ◽  
Cryo Electron Microscopy ◽  
Functional Mechanisms ◽  
The Relationship ◽  
Potential Oxygen

AbstractCytochromes bd are ubiquitous amongst prokaryotes including many human-pathogenic bacteria. Such complexes are targets for the development of antimicrobial drugs. However, an understanding of the relationship between the structure and functional mechanisms of these oxidases is incomplete. Here, we have determined the 2.8 Å structure of Mycobacterium smegmatis cytochrome bd by single-particle cryo-electron microscopy. This bd oxidase consists of two subunits CydA and CydB, that adopt a pseudo two-fold symmetrical arrangement. The structural topology of its Q-loop domain, whose function is to bind the substrate, quinol, is significantly different compared to the C-terminal region reported for cytochromes bd from Geobacillus thermodenitrificans (G. th) and Escherichia coli (E. coli). In addition, we have identified two potential oxygen access channels in the structure and shown that similar tunnels also exist in G. th and E. coli cytochromes bd. This study provides insights to develop a framework for the rational design of antituberculosis compounds that block the oxygen access channels of this oxidase.

scholarly journals Saturation Mutagenesis for Phenylalanine Ammonia Lyases of Enhanced Catalytic Properties

Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 838 ◽  
Author(s):  
Raluca Bianca Tomoiagă ◽  
Souad Diana Tork ◽  
Ilka Horváth ◽  
Alina Filip ◽  
Levente Csaba Nagy ◽  
...  
Keyword(s):  
Rational Design ◽  
Stereoselective Synthesis ◽  
Catalytic Properties ◽  
Catalytic Efficiency ◽  
High Specificity ◽  
Saturation Mutagenesis ◽  
Petroselinum Crispum ◽  
Natural Substrate ◽  
Whole Cells ◽  
Pal Activity

Phenylalanine ammonia-lyases (PALs) are attractive biocatalysts for the stereoselective synthesis of non-natural phenylalanines. The rational design of PALs with extended substrate scope, highlighted the substrate specificity-modulator role of residue I460 of Petroselinum crispum PAL. Herein, saturation mutagenesis at key residue I460 was performed in order to identify PcPAL variants of enhanced activity or to validate the superior catalytic properties of the rationally explored I460V PcPAL compared with the other possible mutant variants. After optimizations, the saturation mutagenesis employing the NNK-degeneracy generated a high-quality transformant library. For high-throughput enzyme-activity screens of the mutant library, a PAL-activity assay was developed, allowing the identification of hits showing activity in the reaction of non-natural substrate, p-MeO-phenylalanine. Among the hits, besides the known I460V PcPAL, several mutants were identified, and their increased catalytic efficiency was confirmed by biotransformations using whole-cells or purified PAL-biocatalysts. Variants I460T and I460S were superior to I460V-PcPAL in terms of catalytic efficiency within the reaction of p-MeO-Phe. Moreover, I460T PcPAL maintained the high specificity constant of the wild-type enzyme for the natural substrate, l-Phe. Molecular docking supported the favorable substrate orientation of p-MeO-cinnamic acid within the active site of I460T variant, similarly as shown earlier for I460V PcPAL (PDB ID: 6RGS).

scholarly journals Rational Design and Testing of Anti-Knock Additives

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4923
Author(s):  
Andrew D. Ure ◽  
Manik K. Ghosh ◽  
Maria Rappo ◽  
Roland Dauphin ◽  
Stephen Dooley
Keyword(s):  
Rational Design ◽  
Reaction Pathway ◽  
Cetane Number ◽  
Research Octane Number ◽  
Ignition Quality ◽  
Ignition Quality Tester ◽  
Generic Design ◽  
The Relationship ◽  
Design And Testing

An innovative and informed methodology for the rational design and testing of anti-knock additives is reported. Interaction of the additives with OH● and HO2● is identified as the key reaction pathway by which non-metallic anti-knock additives are proposed to operate. Based on this mechanism, a set of generic design criteria for anti-knock additives is outlined. It is suggested that these additives should contain a weak X-H bond and form stable radical species after hydrogen atom abstraction. A set of molecular structural, thermodynamic, and kinetic quantities that pertain to the propensity of the additive to inhibit knock by this mechanism are identified and determined for a set of 12 phenolic model compounds. The series of structural analogues was carefully selected such that the physical thermodynamic and kinetic quantities could be systematically varied. The efficacy of these molecules as anti-knock additives was demonstrated through the determination of the research octane number (RON) and the derived cetane number(DCN), measured using an ignition quality tester (IQT), of a RON 95 gasoline treated with 1 mole % of the additive. The use of the IQT allows the anti-knock properties of potential additives to be studied on one tenth of the scale, compared to the analogous RON measurement. Using multiple linear regression, the relationship between DCN/RON and the theoretically determined quantities is studied. The overall methodology reported is proposed as an informed alternative to the non-directed experimental screening approach typically adopted in the development of fuel additives.

Controllable synthesis of Ni nanotube arrays and their structure-dependent catalytic activity toward dye degradation

CrystEngComm ◽  
2014 ◽  
Vol 16 (21) ◽  
pp. 4406-4413 ◽  
Author(s):  
Xiang-Zi Li ◽  
Kong-Lin Wu ◽  
Yin Ye ◽  
Xian-Wen Wei
Keyword(s):  
Catalytic Activity ◽  
Catalytic Properties ◽  
Dye Degradation ◽  
Nanotube Arrays ◽  
Nanorod Arrays ◽  
Growth Mechanisms ◽  
Controllable Synthesis ◽  
Catalytic Activities ◽  
One Step ◽  
The Relationship

Ni nanotube (nanorod) arrays are controllably fabricated by a one-step approach, the GDDATG and DDCG growth mechanisms are introduced. The Ni nanostructures present higher catalytic activities for dye degradation, the relationship between structures and catalytic properties is also studied.

The relationship between RNA catalytic processes

1988 ◽  
Vol 18 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Robert Cedergren ◽  
B. Franz Lang ◽  
Denis Gravel
Keyword(s):  
Catalytic Processes ◽  
The Relationship

scholarly journals Synthesis, Spectroscopic, Thermal, and Catalytic Properties of Eight New Complexes of Metal(II) Formates or Propionates with Imidazole, Relationship between the Carbon Chain Length and Catalytic Activity

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 142
Author(s):  
Bartłomiej Rogalewicz ◽  
Tomasz Maniecki ◽  
Radosław Ciesielski ◽  
Agnieszka Czylkowska
Keyword(s):  
Fourier Transform ◽  
Catalytic Activity ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Chain Length ◽  
Catalytic Properties ◽  
Absorption Spectrometry ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
The Relationship

In one of our previously published articles, we reported the synthesis, spectroscopic, thermal, and catalytic properties of four new M(II) acetate (where M = Co, Ni, Cu, Zn) complexes with imidazole. Presented compounds exhibited activity in the reaction on catalytic oxidation of styrene. In this study we have synthesized and investigated properties of analogous compounds, however using formates or propionates of mentioned metal cations instead of acetates. Such an approach allowed us to draw valuable conclusions concerning the relationship between the carbon chain length and catalytic activity, which is an important factor for catalyst modeling. Synthesized compounds have been thoroughly investigated using appropriate analytic techniques: AAS (Atomic Absorption Spectrometry), FTIR (Fourier-Transform Infrared Spectroscopy), and TGA (Thermogravimetric Analysis). Catalytic properties have been studied under the same previous conditions, using GC-FID (GC-chromatograph equipped with FID detector).

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