scholarly journals Synthetic Peptides as Structural Maquettes of Angiotensin-I Converting Enzyme Catalytic Sites

2010 ◽  
Vol 2010 ◽  
pp. 1-13 ◽  
Author(s):  
Zinovia Spyranti ◽  
Athanassios S. Galanis ◽  
George Pairas ◽  
Georgios A. Spyroulias ◽  
Evy Manessi-Zoupa ◽  
...  
Keyword(s):  
Synthetic Peptides ◽  
Active Sites ◽  
Rational Design ◽  
Transmembrane Domain ◽  
Structural Investigations ◽  
Catalytic Sites ◽  
High Resolution Structure ◽  
Catalytic Active Sites ◽  
Hydrophobic Transmembrane Domain ◽  
Highly Hydrophobic

The rational design of synthetic peptides is proposed as an efficient strategy for the structural investigation of crucial protein domains difficult to be produced. Only after half a century since the function of ACE was first reported, was its crystal structure solved. The main obstacle to be overcome for the determination of the high resolution structure was the crystallization of the highly hydrophobic transmembrane domain. Following our previous work, synthetic peptides and Zinc(II) metal ions are used to build structural maquettes of the two Zn-catalytic active sites of the ACE somatic isoform. Structural investigations of the synthetic peptides, representing the two different somatic isoform active sites, through circular dichroism and NMR experiments are reported.

The protease MBTPS2 is an important regulator of several cellular processes, especially in health and sickness

2021 ◽  
Author(s):  
Moataz Dowaidar
Keyword(s):  
Active Sites ◽  
Peptide Bond ◽  
Cellular Processes ◽  
Disease States ◽  
Tremendous Progress ◽  
Catalytic Sites ◽  
Important Regulator ◽  
Catalytic Active Sites ◽  
Proteolytic Action ◽  
Health And Sickness

Since the identification of MBTPS2 in 1997, tremendous progress has been made in determining the protease's functions. The protease has developed from an element of the SREBP cleavage machinery to an important regulator of several cellular processes, especially in health and sickness. With this newfound information from biochemical and structural biology, S2P's proteolytic action through peptide bond hydrolysis can occur in the membrane, providing a conceptual framework for appreciating S2P's roles in other aspects, and showing that many other substrates rely on S2P for their survival. In addition, we discovered the identity of both of S2P's catalytic active sites, an essential finding as the activity of the proteolysis as well as the pathogenesis of MBTPS2-caused illnesses seems to be connected to the molecular and biochemical features of the catalytic sites. Additionally, MBTPS2 causes different diseases, possibly illustrating the pleiotropic nature of the protein. Also, while the ailments reported thus far are all due to mutations that cause MBTPS2 to lose function, other variants that cause MBTPS2 to be hyperactive have not been examined. Nevertheless, recognizing the related sickness pathomechanism is a challenge. Pursuing these challenging technical areas would most definitely enhance our understanding of MBTPS2 in disease states. MBTPS2 appears to be nearing the solution to many of the remaining fundamental questions surrounding the mechanism of its action, as well as being a therapeutic target for new therapies.

Cleaving DNA-model phosphodiester with Lewis acid–base catalytic sites in bifunctional Zr–MOFs

2019 ◽  
Vol 48 (23) ◽  
pp. 8044-8048 ◽  
Author(s):  
Ying-Hua Zhou ◽  
Zhiyan Zhang ◽  
Margaret Patrick ◽  
Fan Yang ◽  
Rangling Wei ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Active Sites ◽  
Lewis Base ◽  
Zinc Hydroxide ◽  
Acid Base ◽  
Enhanced Activity ◽  
Nitrophenyl Phosphate ◽  
Catalytic Sites ◽  
Catalytic Active Sites ◽  
Hydrolysis Of

UiO-67-bpydc-Zn with isolated multi-catalytic active sites was fabricated as a catalyst for the hydrolysis of bis(p-nitrophenyl) phosphate as a DNA model. The enhanced activity may likely be attributed to the cooperation effects between the Lewis acid from the zirconium center at the node and the zinc hydroxide Lewis base in the linkers.

scholarly journals Insights on forming N,O-coordinated Cu single-atom catalysts for electrochemical reduction CO2 to methane

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yanming Cai ◽  
Jiaju Fu ◽  
Yang Zhou ◽  
Yu-Chung Chang ◽  
Qianhao Min ◽  
...  
Keyword(s):  
Energy Barrier ◽  
Active Sites ◽  
Theoretical Calculations ◽  
High Energy ◽  
Single Atom ◽  
Faradaic Efficiency ◽  
High Energy Barrier ◽  
Catalytic Sites ◽  
Electron Reduction ◽  
First Time

AbstractSingle-atom catalysts (SACs) are promising candidates to catalyze electrochemical CO2 reduction (ECR) due to maximized atomic utilization. However, products are usually limited to CO instead of hydrocarbons or oxygenates due to unfavorable high energy barrier for further electron transfer on synthesized single atom catalytic sites. Here we report a novel partial-carbonization strategy to modify the electronic structures of center atoms on SACs for lowering the overall endothermic energy of key intermediates. A carbon-dots-based SAC margined with unique CuN2O2 sites was synthesized for the first time. The introduction of oxygen ligands brings remarkably high Faradaic efficiency (78%) and selectivity (99% of ECR products) for electrochemical converting CO2 to CH4 with current density of 40 mA·cm-2 in aqueous electrolytes, surpassing most reported SACs which stop at two-electron reduction. Theoretical calculations further revealed that the high selectivity and activity on CuN2O2 active sites are due to the proper elevated CH4 and H2 energy barrier and fine-tuned electronic structure of Cu active sites.

scholarly journals Facile Synthesis of Uniform Mesoporous Nb2O5 Micro-Flowers for Enhancing Photodegradation of Methyl Orange

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3783
Author(s):  
Jian-Qing Qiu ◽  
Huan-Qing Xie ◽  
Ya-Hao Wang ◽  
Lan Yu ◽  
Fang-Yuan Wang ◽  
...  
Keyword(s):  
Methyl Orange ◽  
Active Sites ◽  
High Performance ◽  
Diffuse Reflectance Spectroscopy ◽  
X Ray Diffraction ◽  
Flower Structure ◽  
Electron Microscopies ◽  
Bet Method ◽  
One Step ◽  
Catalytic Active Sites

The removal of organic pollutants using green environmental photocatalytic degradation techniques urgently need high-performance catalysts. In this work, a facile one-step hydrothermal technique has been successfully applied to synthesize a Nb2O5 photocatalyst with uniform micro-flower structure for the degradation of methyl orange (MO) under UV irradiation. These nanocatalysts are characterized by transmission and scanning electron microscopies (TEM and SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) method, and UV-Vis diffuse reflectance spectroscopy (DRS). It is found that the prepared Nb2O5 micro-flowers presents a good crystal phases and consist of 3D hierarchical nanosheets with 400–500 nm in diameter. The surface area is as large as 48.6 m2 g−1. Importantly, the Nb2O5 micro-flowers exhibit superior catalytic activity up to 99.9% for the photodegradation of MO within 20 mins, which is about 60-fold and 4-fold larger than that of without catalysts (W/O) and commercial TiO2 (P25) sample, respectively. This excellent performance may be attributed to 3D porous structure with abundant catalytic active sites.

scholarly journals Phase-selective active sites on ordered/disordered titanium dioxide enable exceptional photocatalytic ammonia synthesis

2021 ◽  
Author(s):  
Jinsun Lee ◽  
Xinghui Liu ◽  
Ashwani Kumar ◽  
Yosep Hwang ◽  
Eunji Lee ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Active Sites ◽  
Rational Design ◽  
Ammonia Synthesis ◽  
Reduction Reaction ◽  
Band Structures ◽  
Electronic Band ◽  
Defect Sites ◽  
Electronic Band Structures ◽  
Reaction Routes

This work highlights the importance of a rational design for more energetically suitable nitrogen reduction reaction routes and mechanisms by regulating the electronic band structures with phase-selective defect sites.

scholarly journals NaBr Poisoning of Au/TiO2 Catalysts: Effects on Kinetics, Poisoning Mechanism, and Estimation of the Number of Catalytic Active Sites

ACS Catalysis ◽  
2012 ◽  
Vol 2 (4) ◽  
pp. 684-694 ◽  
Author(s):  
Bert D. Chandler ◽  
Shane Kendell ◽  
Hieu Doan ◽  
Rachel Korkosz ◽  
Lars C. Grabow ◽  
...  
Keyword(s):  
Active Sites ◽  
Catalytic Active Sites

scholarly journals Engineering single-atomic ruthenium catalytic sites on defective nickel-iron layered double hydroxide for overall water splitting

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Panlong Zhai ◽  
Mingyue Xia ◽  
Yunzhen Wu ◽  
Guanghui Zhang ◽  
Junfeng Gao ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Water Splitting ◽  
Layered Double Hydroxide ◽  
Hydrogen Evolution Reaction ◽  
Active Sites ◽  
Density Functional ◽  
Rational Design ◽  
Single Atom ◽  
Nickel Iron ◽  
Double Hydroxide

AbstractRational design of single atom catalyst is critical for efficient sustainable energy conversion. However, the atomic-level control of active sites is essential for electrocatalytic materials in alkaline electrolyte. Moreover, well-defined surface structures lead to in-depth understanding of catalytic mechanisms. Herein, we report a single-atomic-site ruthenium stabilized on defective nickel-iron layered double hydroxide nanosheets (Ru1/D-NiFe LDH). Under precise regulation of local coordination environments of catalytically active sites and the existence of the defects, Ru1/D-NiFe LDH delivers an ultralow overpotential of 18 mV at 10 mA cm−2 for hydrogen evolution reaction, surpassing the commercial Pt/C catalyst. Density functional theory calculations reveal that Ru1/D-NiFe LDH optimizes the adsorption energies of intermediates for hydrogen evolution reaction and promotes the O–O coupling at a Ru–O active site for oxygen evolution reaction. The Ru1/D-NiFe LDH as an ideal model reveals superior water splitting performance with potential for the development of promising water-alkali electrocatalysts.

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