Functional analyses for tRNase Z variants: An aspartate and a histidine in the active site are essential for the catalytic activity

Novel flower-shaped C-dots/Co3O4{111} with dual-reaction centers were constructed to improve the Fenton-like reaction activity and peroxymonosulfate (PMS) conversion to sulfate radicals. Due to the exposure of a high surface area and Co3O4{111} facets, flower-shaped C-dots/Co3O4{111} could provide more Co(II) for PMS activation than traditional spherical Co3O4{110}. Meanwhile, PMS was preferred for adsorption on Co3O4{111} facets because of a high adsorption energy and thereby facilitated the electron transfer from Co(II) to PMS. More importantly, the Co–O–C linkage between C-dots and Co3O4{111} induced the formation of the dual-reaction center, which promoted the production of reactive organic radicals (R•). PMS could be directly reduced to SO4−• by R• over C-dots. On the other hand, electron transferred from R• to Co via Co–O–C linkage could accelerate the redox of Co(II)/(III), avoiding the invalid decomposition of PMS. Thus, C-dots doped on Co3O4{111} improved the PMS conversion rate to SO4−• over the single active site, resulting in high turnover numbers (TONs). In addition, TPR analysis indicated that the optimal content of C-dots doped on Co3O4{111} is 2.5%. More than 99% of antibiotics and dyes were degraded over C-dots/Co3O4{111} within 10 min. Even after six cycles, C-dots/Co3O4{111} still remained a high catalytic activity.

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Dehydration of n-Butanol on Phosphate-Modified Carbon Nanotubes: Active Site and Intrinsic Catalytic Activity

Catalysis Science & Technology ◽

10.1039/d1cy00426c ◽

2021 ◽

Author(s):

Fan Li ◽

Xueya Dai ◽

Xingyu Lu ◽

Chao Wang ◽

Wei Qi

Keyword(s):

Carbon Nanotubes ◽

Catalytic Activity ◽

Active Site ◽

Efficient Utilization ◽

Reaction Route ◽

Modified Carbon Nanotubes

Dehydration of n-butanol (nB) to corresponding olefins (butene) is an important reaction route to realize the efficient utilization of bulk bio-alcohols. In this work, a novel phosphate modified oxidized multi-walled...

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A possible connection between phosphate tungsten bronzes properties and Briggs-Rauscher oscillatory reaction response

Science of Sintering ◽

10.2298/sos2102223m ◽

2021 ◽

Vol 53 (2) ◽

pp. 223-235

Author(s):

Tijana Maksimovic ◽

Jelena Maksimovic ◽

Pavle Tancic ◽

Nebojsa Potkonjak ◽

Zoran Nedic ◽

...

Keyword(s):

Catalytic Activity ◽

Calcium Phosphate ◽

Active Site ◽

Unit Cell Volume ◽

Tungsten Bronze ◽

Reaction Dynamics ◽

Unit Cell ◽

Oscillatory Reaction ◽

Innovative Method ◽

Cell Volumes

The calcium phosphate tungsten bronze (Ca-PWB) has been synthesized and characterized (TGA, DSC, XRPD, FTIR, SEM). The influence of solid insoluble materials Ca- PWB, as well as lithium doped (Li-PWB) and cation free phosphate tungsten (PWB) bronzes on the oscillatory Briggs-Rauscher (BR) reaction dynamics, is compared. The results show that doping with Li and Ca reduces sensitivity of the BR reaction towards bronzes addition. These findings suggest the usage of the BR reaction as an innovative method for testing of different properties of bronze material. The behavior of PWB in the BR reaction is significantly changed with divalent cation (Ca2+) doping. The reasons for the different bronzes behavior were found in their calculated unit cell volumes. Namely, the compressed Ca-PWB unit cell volume indicates the difficult availability of the active site for heterogeneous catalysis. Hence, the linear correlation (slope) of the BR oscillogram?s length (?osc) vs. mass of bronze in BR reaction might be considered as a new parameter for the evaluation of the bronzes catalytic activity.

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Understanding the Catalytic Activity of Microporous and Mesoporous Zeolites in Cracking by Experiments and Simulations

Catalysts ◽

10.3390/catal11091114 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1114

Author(s):

Shih-Cheng Li ◽

Yen-Chun Lin ◽

Yi-Pei Li

Keyword(s):

Catalytic Activity ◽

Active Site ◽

Petrochemical Industry ◽

Molecular Level ◽

Shape Selectivity ◽

Zeolite Catalysts ◽

Hydrocarbon Cracking ◽

Mesoporous Zeolites ◽

Secondary Reactions ◽

Pros And Cons

Porous zeolite catalysts have been widely used in the industry for the conversion of fuel-range molecules for decades. They have the advantages of higher surface area, better hydrothermal stability, and superior shape selectivity, which make them ideal catalysts for hydrocarbon cracking in the petrochemical industry. However, the catalytic activity and selectivity of zeolites for hydrocarbon cracking are significantly affected by the zeolite topology and composition. The aim of this review is to survey recent investigations on hydrocarbon cracking and secondary reactions in micro- and mesoporous zeolites, with the emphasis on the studies of the effects of different porous environments and active site structures on alkane adsorption and activation at the molecular level. The pros and cons of different computational methods used for zeolite simulations are also discussed in this review.

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Active site engineering by surface sulfurization for a highly efficient oxygen evolution reaction: a case study of Co3O4 electrocatalysts

Journal of Materials Chemistry A ◽

10.1039/c8ta08211a ◽

2018 ◽

Vol 6 (45) ◽

pp. 22497-22502 ◽

Cited By ~ 23

Author(s):

Ying Pan ◽

Hangjuan Ren ◽

Haiwei Du ◽

Fuyang Cao ◽

Yifeng Jiang ◽

...

Keyword(s):

Catalytic Activity ◽

Oxygen Evolution ◽

Active Site ◽

Oxygen Evolution Reaction ◽

Highly Efficient

Enhanced catalytic activity of Co3O4@CoSx through surface sulfurization.

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The effect of ionic liquid on the structure of active site pocket and catalytic activity of a β-glucosidase from Halothermothrix orenii

Journal of Molecular Liquids ◽

10.1016/j.molliq.2020.112879 ◽

2020 ◽

Vol 306 ◽

pp. 112879 ◽

Cited By ~ 1

Author(s):

Sukanya Konar ◽

Sushant K. Sinha ◽

Supratim Datta ◽

Pradip Kr. Ghorai

Keyword(s):

Ionic Liquid ◽

Catalytic Activity ◽

Active Site ◽

Active Site Pocket

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The interactome of 2-Cys peroxiredoxins in Plasmodium falciparum

Scientific Reports ◽

10.1038/s41598-019-49841-3 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Christina Brandstaedter ◽

Claire Delahunty ◽

Susanne Schipper ◽

Stefan Rahlfs ◽

John R. Yates ◽

...

Keyword(s):

Plasmodium Falciparum ◽

Active Site ◽

Cellular Protein ◽

Mitochondrial Proteins ◽

Target Proteins ◽

Cellular Processes ◽

Mixed Disulfide ◽

Functional Analyses ◽

Cell Proteome ◽

Active Site Mutants

Abstract Peroxiredoxins (Prxs) are crucially involved in maintaining intracellular H2O2 homeostasis via their peroxidase activity. However, more recently, this class of proteins was found to also transmit oxidizing equivalents to selected downstream proteins, which suggests an important function of Prxs in the regulation of cellular protein redox relays. Using a pull-down assay based on mixed disulfide fishing, we characterized the thiol-dependent interactome of cytosolic Prx1a and mitochondrial Prx1m from the apicomplexan malaria parasite Plasmodium falciparum (Pf). Here, 127 cytosolic and 20 mitochondrial proteins that are components of essential cellular processes were found to interact with PfPrx1a and PfPrx1m, respectively. Notably, our data obtained with active-site mutants suggests that reducing equivalents might also be transferred from Prxs to target proteins. Initial functional analyses indicated that the interaction with Prx can strongly impact the activity of target proteins. The results provide initial insights into the interactome of Prxs at the level of a eukaryotic whole cell proteome. Furthermore, they contribute to our understanding of redox regulatory principles and thiol-dependent redox relays of Prxs in subcellular compartments.

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3-D Structure of Serum Paraoxonase 1 Sheds Light on Its Activity, Stability, Solubility and Crystallizability

Archives of Industrial Hygiene and Toxicology ◽

10.2478/v10004-007-0028-0 ◽

2007 ◽

Vol 58 (3) ◽

pp. 347-353 ◽

Cited By ~ 20

Author(s):

Michal Harel ◽

Boris Brumshtein ◽

Ran Meged ◽

Hay Dvir ◽

Raimond Ravelli ◽

...

Keyword(s):

Crystal Structure ◽

Catalytic Activity ◽

High Density Lipoprotein ◽

Active Site ◽

Density Lipoprotein ◽

Paraoxonase 1 ◽

Hydrolytic Activities ◽

Wide Range ◽

The Stability ◽

Serum Paraoxonase

3-D Structure of Serum Paraoxonase 1 Sheds Light on Its Activity, Stability, Solubility and CrystallizabilitySerum paraoxonases (PONs) exhibit a wide range of physiologically important hydrolytic activities, including drug metabolism and detoxification of nerve gases. PON1 and PON3 reside on high-density lipoprotein (HDL) (the "good cholesterol"), and are involved in the alleviation of atherosclerosis. Members of the PON family have been identified not only in mammals and other vertebrates, but also in invertebrates. We earlier described the first crystal structure of a PON family member, a directly-evolved variant of PON1, at 2.2 Å resolution. PON1 is a 6-bladed beta-propeller with a unique active-site lid which is also involved in binding to HDL. The 3-D structure, taken together with directed evolution studies, permitted analysis of mutations which enhanced the stability, solubility and crystallizability of this PON1 variant. The structure permits a detailed description of PON1's active site and suggests possible mechanisms for its catalytic activity on certain substrates.

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