PubAg

Main content area

You searched for: Subject "active sites" Remove constraint Subject: "active sites"
Start Over

Search

12,599  Search Results

« Previous | 1 - 20 of 12,599 |
Number of results to display per page

Search Results

1. Syntheses and biological evaluation of BE-43547A2 analogues modified at O35 ester and C15-OH sites

Author:
Sun, Yuanjun; Zhou, Ruifei; Xu, Honglei; Wang, Dehong; Su, Xiuwen; Wang, Chao; Ding, Yahui; Wang, Liang; Chen, Yue
Source:
Tetrahedron 2019 v.75 no.12 pp. 1808-1818
ISSN:
0040-4020
Subject:
active sites,   etc   ; organic compounds; oxidation;     Show all 3 Subjects
Abstract:
... Total syntheses of 6 BE-43547A2 analogues modified at O35 and C15 sites are reported. Late stage oxidation of 15-deoxy-BE-43547A2 delivered 15-epi-BE-43547A2, which verified the proposition that the C15 is an active site for late stage oxidation. The N35 and C15-F of analogues 1b and 1d were synthesized. Cellular level tests indicated O35 is a prohibitive site for modification and substitution of ...
DOI:
10.1016/j.tet.2018.12.053

2. Can laccase-assisted processing conditions influence the structure of reaction products?

Author:
Su, Jing; Fu, Jiajia; Silva, Carla; Cavaco-Paulo, Artur
Source:
Trends in biotechnology 2019
ISSN:
0167-7799
Subject:
active sites,   etc   ; catechol; geometry; laccase;     Show all 4 Subjects
Abstract:
... Laccase is a promiscuous enzyme known to catalyse a wide range of phenolic substrates. Several poly(catechol) products can be obtained when processing modified enzymes or different reactors are used. The differentiated reaction products may be attributed to changes on the enzyme active site geometry induced by different environmental reaction settings. ...
DOI:
10.1016/j.tibtech.2019.03.006

3. Tuning the fill percentage in the hydrothermal synthesis process to increase catalyst performance for ozone decomposition

Author:
Yang, Li; Ma, Jinzhu; Li, Xiaotong; He, Guangzhi; Zhang, Changbin; He, Hong
Source:
Journal of environmental sciences (China) 2020 v.87 pp. 60-70
ISSN:
1001-0742
Subject:
active sites,   etc   ; X-ray photoelectron spectroscopy; catalysts; cerium; ions; manganese; oxygen; ozone;     Show all 8 Subjects
Abstract:
... The performance of Ce-OMS-2 catalysts was improved by tuning the fill percentage in the hydrothermal synthesis process to increase the oxygen vacancy density. The Ce-OMS-2 samples were prepared with different fill percentages by means of a hydrothermal approach (i.e. 80%, 70%, 50% and 30%). Ce-OMS-2 with 80% fill percentage (Ce-OMS-2-80%) showed ozone conversion of 97%, and a lifetime experiment c ...
DOI:
10.1016/j.jes.2019.06.007

4. Dinickel catalyzed carbonylation reactions using metal carbonyl reagents as CO sources

Author:
Adolph, Colby M.; Lee, Seul Ah; Zeller, Matthias; Uyeda, Christopher
Source:
Tetrahedron 2019 v.75 no.24 pp. 3336-3340
ISSN:
0040-4020
Subject:
active sites,   etc   ; chemical reactions; organic compounds;     Show all 3 Subjects
Abstract:
... Dinickel complexes promote stoichiometric Pauson–Khand reactions of enynes and CO (g). However, catalytic turnover is precluded by the strong binding of CO to the Ni2 active site. This article describes the use of M(CO)x reagents as stoichiometric CO precursors in Ni2-catalyzed carbonylation reactions. As part of these studies, well-defined heterotrinuclear Ni2Fe, Ni2Co, and Ni2Mn carbonyl cluster ...
DOI:
10.1016/j.tet.2019.04.064

5. Strategy for stabilizing noble metal nanoparticles without sacrificing active sites

Author:
Ji, Weikang; Wang, Xuyu; Tang, Minni; Yang, Le; Rui, Zebao; Tong, Yexiang; Lin, Jerry Y. S.
Source:
Chemical communications 2019 v.55 no.48 pp. 6846-6849
ISSN:
1364-548X
Subject:
active sites,   etc   ; nanoparticles; oxidation; titanium dioxide; toluene;     Show all 5 Subjects
Abstract:
... We report a facile surface fluorination strategy for restricting Pt nanoparticle sintering through providing anchoring sites on the TiO₂ support and enhancing metal–support interaction via improved electronic interaction without sacrificing the active sites. The fluorine-tailored Pt/TiO₂ exhibits excellent sintering resistance and significant activity enhancement in the catalytic oxidation of tolu ...
DOI:
10.1039/c9cc03066b

6. Architecture and Performance of the Novel Sulfur Host Material Based on Ti₂O₃ Microspheres for Lithium–Sulfur Batteries

Author:
Zeng, Peng; Chen, Manfang; Jiang, Shouxin; Li, Yongfang; Xie, Xin; Liu, Hong; Hu, Xinyu; Wu, Chun; Shu, Hongbo; Wang, Xianyou
Source:
ACS applied materials & interfaces 2019 v.11 no.25 pp. 22439-22448
ISSN:
1944-8252
Subject:
active sites,   etc   ; absorption; electrochemistry; microparticles; sulfur;     Show all 5 Subjects
Abstract:
... Lithium–sulfur batteries are considered as promising next-generation green secondary batteries. Irrespective of the enhancement of the cycling stability or the suppression of polysulfide species shuttle, although much progress has recently been achieved, improving the conductivity of host materials and capturing the sulfide species as far as possible are still hot topics in the research of lithium ...
DOI:
10.1021/acsami.9b05874

7. The broad-specificity chitinases: their origin, characterization, and potential application

Author:
Zhou, Jie; Chen, Jianhao; Xu, Ning; Zhang, Alei; Chen, Kequan; Xin, Fengxue; Zhang, Wenming; Ma, Jiangfeng; Fang, Yan; Jiang, Min; Dong, Weiliang
Source:
Applied microbiology and biotechnology 2019 v.103 no.8 pp. 3289-3295
ISSN:
0175-7598
Subject:
active sites,   etc   ; biotechnology; catalytic activity; chitin; chitinase;     Show all 5 Subjects
Abstract:
... Chitinases are hydrolases that catalyze the cleavage of the β-1,4-O-glycosidic linkages in chitin, a polysaccharide abundantly found in nature. Although numerous chitinolytic enzymes have been studied in detail, relatively little is known about chitinases capable of broad specificity. Broad-specificity chitinases are a sort of novel chitinases possessing two or three different catalytic activities ...
DOI:
10.1007/s00253-019-09718-x

8. Selenium vacancy-rich CoSe₂ ultrathin nanomeshes with abundant active sites for electrocatalytic oxygen evolution

Author:
Zhang, Yixin; Zhang, Chao; Guo, Yamei; Liu, Dali; Yu, Yifu; Zhang, Bin
Source:
Journal of materials chemistry A 2019 v.7 no.6 pp. 2536-2540
ISSN:
2050-7496
Subject:
active sites,   etc   ; electrolytes; engineering; oxygen production; selenium;     Show all 5 Subjects
Abstract:
... CoSe₂ is a promising electrocatalyst for the oxygen evolution reaction (OER), benefiting from its suitable electronic configuration and inherent metallic behavior. However, the low ratio of electrolyte-accessible active sites suppresses the OER performance of pure CoSe₂. Engineering CoSe₂ into a two-dimensional ultrathin nanomesh structure with abundant selenium vacancies is expected to increase i ...
DOI:
10.1039/c8ta11407b

9. M17 aminopeptidases diversify function by moderating their macromolecular assemblies and active site environment

Author:
Drinkwater, Nyssa; Malcolm, Tess R.; McGowan, Sheena
Source:
Biochimie 2019
ISSN:
0300-9084
Subject:
active sites,   etc   ; amino acids; aminopeptidases; peptides; proteolysis;     Show all 5 Subjects
Abstract:
... The family of M17 aminopeptidases (alias ‘leucine aminopeptidases’, M17-LAPs) utilize a highly conserved hexameric structure and a binuclear metal center to selectively remove N-terminal amino acids from short peptides. However, M17-LAPs are responsible for a wide variety of functions that are seemingly unrelated to proteolysis. Herein, we aimed to investigate the myriad of functions attributed to ...
DOI:
10.1016/j.biochi.2019.01.007

10. Rotating Catalysts Are Superior: Suppressing Product Inhibition by Anchimeric Assistance in Four-Component Catalytic Machinery

Author:
Biswas, Pronay Kumar; Saha, Suchismita; Paululat, Thomas; Schmittel, Michael
Source:
Journal of the American Chemical Society 2018 v.140 no.29 pp. 9038-9041
ISSN:
1520-5126
Subject:
active sites,   etc   ; catalysts;     Show all 2 Subject
Abstract:
... Three distinct four-component supramolecular nanorotors, prepared by varying the rotator’s structure and keeping all other components constant, exhibit rotational frequencies that differ by almost 2 orders of magnitude. When the rotors were used as catalyst for two click reactions, the product yield correlated with the speed of the machine, e.g., 20% at 0.50 kHz, 44% at 20 kHz and 62% at 42 kHz. T ...
DOI:
10.1021/jacs.8b04437

11. Simulation of Intermediate Channeling by Nanoscale Confinement C

Author:
Chavan, Kanchan Suklal; Calabrese Barton, Scott
Source:
Journal of physical chemistry 2018 v.122 no.26 pp. 14474-14480
ISSN:
1932-7455
Subject:
active sites,   etc   ; geometry; models;     Show all 3 Subjects
Abstract:
... Confinement of active sites and reaction intermediates in a physical tunnel is one example of intermediate channeling found in natural reaction cascades. The study of transport properties and their impact on kinetics of these confined systems provides a pathway for implementing confinement strategies in integrated and intensified catalytic systems. In the present study, the effect of geometric, ki ...
DOI:
10.1021/acs.jpcc.8b01922

12. A Family Divided: Distinct Structural and Mechanistic Features of the SpoU-TrmD (SPOUT) Methyltransferase Superfamily

Author:
Krishnamohan, Aiswarya; Jackman, Jane E.
Source:
Biochemistry 2018 v.58 no.5 pp. 336-345
ISSN:
1520-4995
Subject:
active sites,   etc   ; RNA; dimerization; methyltransferases;     Show all 4 Subjects
Abstract:
... The SPOUT family of enzymes makes up the second largest of seven structurally distinct groups of methyltransferases and is named after two evolutionarily related RNA methyltransferases, SpoU and TrmD. A deep trefoil knotted domain in the tertiary structures of member enzymes defines the SPOUT family. For many years, formation of a homodimeric quaternary structure was thought to be a strict require ...
DOI:
10.1021/acs.biochem.8b01047

13. Directed Evolution as a Probe of Rate Promoting Vibrations Introduced via Mutational Change

Author:
Chen, Xi; Schwartz, Steven D.
Source:
Biochemistry 2018 v.57 no.23 pp. 3289-3298
ISSN:
1520-4995
Subject:
active sites,   etc   ; directed evolution; enzymes;     Show all 3 Subjects
Abstract:
... In this article, we study with transition path sampling and reaction coordinate analysis how directed evolution in the Kemp eliminase family of artificial enzymes makes differential use of rapid rate promoting vibrations as a component of their chemical mechanism. Even though this family was initially created by placing the expected active site in a fixed protein matrix, we find a shift from large ...
DOI:
10.1021/acs.biochem.8b00185

14. Nano-sized architectural design of multi-activity graphene oxide (GO) by chemical post-decoration for efficient uranium(VI) extraction

Author:
Yang, Peipei; Zhang, Hongsen; Liu, Qi; Liu, Jingyuan; Chen, Rongrong; Yu, Jing; Hou, Jindi; Bai, Xuefeng; Wang, Jun
Source:
Journal of hazardous materials 2019 v.375 pp. 320-329
ISSN:
0304-3894
Subject:
active sites,   etc   ; adsorption; blood platelets; graphene oxide; seawater; uranium;     Show all 6 Subjects
Abstract:
... The introduction of organic groups onto graphene oxide (GO) platelets can supply additional active sites for adsorption of uranium(VI) (U(VI)) to improve the adsorption capacity. However, as a result of the existence of stabilizing π-conjugation system, a facile and effective modification method remains a challenge. Therefore, a novel strategy is exploited by nano-sized architectural design of mul ...
DOI:
10.1016/j.jhazmat.2019.05.005

15. High gravimetric and volumetric sodium storage in a functionalized coal-based microcrystal/CNT binder-free electrode

Author:
Miao, Siyu; Zhao, Hanqing; Kang, Mengmeng; Shen, Hanting; Song, Wei; Zhao, Dan; Ye, Jianqi; Li, Zhong
Source:
Chemical communications 2019 v.55 no.55 pp. 7954-7957
ISSN:
1364-548X
Subject:
active sites,   etc   ; anhydrides; chemical reactions; electrodes; moieties; oxygen; quinones; sodium;     Show all 8 Subjects
Abstract:
... Abundant oxygen functional groups in coal-based microcrystals, especially for carboxylic anhydrides and quinone groups with two Na⁺ storage sites, provide plentiful active sites to adsorb Na⁺. The carboxyl groups serve as the binder connecting active material with a current collector. High gravimetric and volumetric sodium storage was achieved in this binder-free electrode. ...
DOI:
10.1039/c9cc02586c

16. Efficient depolymerization of Kraft lignin to liquid fuels over an amorphous titanium-zirconium mixed oxide supported partially reduced nickel-cobalt catalyst

Author:
Zhu, Chaofeng; Dou, Xiaomeng; Li, Wenzhi; Liu, Xiaohao; Li, Qingqing; Ma, Jianru; Liu, Qiying; Ma, Longlong
Source:
Bioresource technology 2019 v.284 pp. 293-301
ISSN:
0960-8524
Subject:
active sites,   etc   ; Lewis acids; catalysts; depolymerization; lignin; liquids; petroleum; synergism;     Show all 8 Subjects
Abstract:
... A series of non-precious metal/metal oxide nickel-cobalt catalysts was prepared for a highly efficient depolymerization of Kraft lignin (KL) into liquid fuels using amorphous TiZr-oxide (Ti1−yZryO2) as a carrier. The effects of Ni-NiOx, Co-CoOx, NiCo-NiCoOx, NiCoOx and NiCo catalysts supported on amorphous TiZr-oxide carrier on KL depolymerization were investigated. It was found that the NiCo-NiCo ...
DOI:
10.1016/j.biortech.2019.03.126

17. Imidazolium-based SILLPs as organocatalysts in silane production: Synthesis, characterization and catalytic activity

Author:
Vorotyntsev, Andrey V.; Petukhov, Anton N.; Sazanova, Tatyana S.; Pryakhina, Victoria I.; Nyuchev, Alexander V.; Otvagina, Ksenia V.; Markov, Artem N.; Atlaskina, Maria E.; Vorotyntsev, Ilya V.; Vorotyntsev, Vladimir M.
Source:
Journal of catalysis 2019 v.375 pp. 427-440
ISSN:
0021-9517
Subject:
active sites,   etc   ; catalytic activity; imidazoles; organocatalysts; polymers; reaction mechanisms; silane;     Show all 7 Subjects
Abstract:
... The catalytic activity of imidazolium-based SILLPs stabilised onto DVB/CMS catalyst supports is evaluated to develop “Union Carbide” process catalytic systems. Under similar conditions, SILLPs based on 4-Methyl Imidazole behave as more active catalysts in trichlorosilane disproportionation in part of silane yield. In these systems, the polymer support is not only an inert matrix. The polymer is de ...
DOI:
10.1016/j.jcat.2019.05.021

18. Unveiling the active sites of Ni–Fe phosphide/metaphosphate for efficient oxygen evolution under alkaline conditions

Author:
Huang, Can; Zou, Ying; Ye, Ya-Qian; Ouyang, Ting; Xiao, Kang; Liu, Zhao-Qing
Source:
Chemical communications 2019 v.55 no.53 pp. 7687-7690
ISSN:
1364-548X
Subject:
active sites,   etc   ; catalysts; chemical reactions; electrolysis; iron; oxygen production; phosphides;     Show all 7 Subjects
Abstract:
... The highly active and stable oxygen evolution reaction (OER) performance of Ni–Fe phosphide/metaphosphate (Ni₁₋ₓFeₓ-P/PO₃) can originate from in situ generated Fe doped γ-NiOOH. The optimized Ni₀.₇₅Fe₀.₂₅-P/PO₃@fCNT catalyst exhibits excellent activity and stability with an overpotential of 239 mV at 10 mA cm⁻² and a negligible decrease after 200 h continuous electrolysis in an alkaline solution. ...
DOI:
10.1039/c9cc03024g

19. Functional Landscape of PCGF Proteins Reveals Both RING1A/B-Dependent-and RING1A/B-Independent-Specific Activities

Author:
Scelfo, Andrea; Fernández-Pérez, Daniel; Tamburri, Simone; Zanotti, Marika; Lavarone, Elisa; Soldi, Monica; Bonaldi, Tiziana; Ferrari, Karin Johanna; Pasini, Diego
Source:
Molecular cell 2019 v.74 no.5 pp. 1037-1052.e7
ISSN:
1097-2765
Subject:
active sites,   etc   ; DNA; genes; heterochromatin; ligases; transcription (genetics); transcription factors;     Show all 7 Subjects
Abstract:
... Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) control cell identity by establishing facultative heterochromatin repressive domains at common sets of target genes. PRC1, which deposits H2Aub1 through the E3 ligases RING1A/B, forms six biochemically distinct subcomplexes depending on the assembled PCGF protein (PCGF1–PCGF6); however, it is yet unclear whether these subcomplexes have also spe ...
DOI:
10.1016/j.molcel.2019.04.002

20. An Integrated Single-Electrode Method Reveals the Template Roles of Atomic Steps: Disturb Interfacial Water Networks and Thus Affect the Reactivity of Electrocatalysts

Author:
Zhao, Xiao; Gunji, Takao; Kaneko, Takuma; Yoshida, Yusuke; Takao, Shinobu; Higashi, Kotaro; Uruga, Tomoya; He, Wenxiang; Liu, Jianguo; Zou, Zhigang
Source:
Journal of the American Chemical Society 2019 v.141 no.21 pp. 8516-8526
ISSN:
1520-5126
Subject:
active sites,   etc   ; catalysts; electrochemistry; electrodes; transmission electron microscopy;     Show all 5 Subjects
Abstract:
... A method enabling the accurate and precise correlation between structures and properties is critical to the development of efficient electrocatalysts. To this end, we developed an integrated single-electrode method (ISM) that intimately couples electrochemical rotating disk electrodes, in situ/operando X-ray absorption fine structures, and aberration-corrected transmission electron microscopy on i ...
DOI:
10.1021/jacs.9b02049