scholarly journals Self-assembly Is Prerequisite for Catalysis of Fe(II) Oxidation by Catalytically Active Subunits of Ferritin

2015 ◽  
Vol 290 (44) ◽  
pp. 26801-26810 ◽  
Author(s):  
Kourosh Honarmand Ebrahimi ◽  
Peter-Leon Hagedoorn ◽  
Wilfred R. Hagen
2016 ◽  
Vol 52 (10) ◽  
pp. 2133-2136 ◽  
Author(s):  
Krunoslav Užarević ◽  
Timothy C. Wang ◽  
Su-Young Moon ◽  
Athena M. Fidelli ◽  
Joseph T. Hupp ◽  
...  

Mechanochemistry and accelerated aging are new routes to zirconium metal–organic frameworks, yielding UiO-66 and catalytically active UiO-66-NH2 accessible on the gram scale through mild solid-state self-assembly, without strong acids, high temperatures or excess reactants.


2019 ◽  
Vol 141 (26) ◽  
pp. 10350-10360 ◽  
Author(s):  
Rosa Adam ◽  
Marta Mon ◽  
Rossella Greco ◽  
Lucas H. G. Kalinke ◽  
Alejandro Vidal-Moya ◽  
...  

2015 ◽  
Vol 17 (24) ◽  
pp. 15579-15588 ◽  
Author(s):  
Andrew Booth ◽  
Inmaculada C. Pintre ◽  
Yue Lin ◽  
Julie E. Gough ◽  
Simon J. Webb

The self-assembly of avidin, biotinylated vesicles and biotinylated (3-aminopropyl)triethoxysilane-coated magnetite nanoparticles gave a nanomaterial able to magnetically release catalytically active enzymes from vesicular compartments.


RSC Advances ◽  
2015 ◽  
Vol 5 (105) ◽  
pp. 86564-86571 ◽  
Author(s):  
Qian Wang ◽  
Xingjuan Zhao ◽  
Yong-Ill Lee ◽  
Hong-Guo Liu

A catalytically active multilayer film of PB-b-P2VP doped with Au nanoparticles was fabricated through liquid/liquid interfacial mass transfer, self-assembly in an aqueous phase and adsorption at the air/liquid interface.


2019 ◽  
Vol 2 (8) ◽  
pp. 3639-3647 ◽  
Author(s):  
Valeria Castelletto ◽  
Charlotte J. C. Edwards-Gayle ◽  
Ian W. Hamley ◽  
Juliane N. B. D. Pelin ◽  
Wendel A. Alves ◽  
...  

Synlett ◽  
2021 ◽  
Author(s):  
Joaquim Crusats ◽  
Albert Moyano

In order to explain the origin of the single-handedness of the molecules of life (biological homochirality), the appearence of an initial enantiomeric imbalance by spontaneous mirror-symmetry breaking (SMSB) in prebiotic reactions is usually assumed, but examples of its experimental realization are very scarce. SMSB in the self-assembly of achiral molecules is much more common, and the chirality sign of the resulting supramolecular system can be controlled by the action of macroscopic chiral forces. We have proposed a new mechanism for the generation of net chirality in molecular systems, in which the SMSB takes place in the formation of chiral supramolecular dissipative structures from achiral monomers, leading to asymmetric imbalances in their composition that are subsequently transferred to a standard enantioselective catalytic reaction, dodging in this way the highly limiting requirement of finding suitable reactions in solution that show enantioselective autocatalysis. We propose the name “absolute asymmetric catalysis” for this approach, in which an achiral monomer is converted to a nonracemic chiral aggregate that is generated with SMSB and that is catalytically active. We present in this Account a step-by-step narrative of the development of this prebiotically plausible, alternative mechanism for the emergence of net chirality in molecular reactions.


1988 ◽  
Vol 254 (1) ◽  
pp. 123-130 ◽  
Author(s):  
G G Chang ◽  
T M Huang ◽  
T C Chang

The pH-induced reversible dissociation of pigeon liver malic enzyme (EC 1.1.1.40) was studied by combined use of chemical cross-linking and SDS/polyacrylamide-gel electrophoresis. The tetrameric enzyme showed a pH-dependent dissociation in an acidic environment. At pH values above 8.0 most molecules existed as tetramers. The enzyme was gradually dissociated at lower pH. When the pH was below 5.0 most of the enzyme was present as the monomeric forms. Reassociation of the subunits was accomplished by adjusting the pH to neutrality. The dissociation and reassociation were almost instantaneous. No trimer was detected. The pigeon liver malic enzyme was thus shown to have a double-dimer quaternary structure with D2 symmetry. In the presence of substrates, the monomer-dimer-tetramer equilibrium favours the direction of dissociation. Tartronate, an L-malate analogue, was found to be more effective than L-malate in this process. When the monomeric forms were immobilized, the enzyme subunits were found to be fully active in catalysis. A possible arrangement of the four identical subunits of the enzyme molecule is proposed to account for the results obtained in this investigation. The origin of the half-of-the-sites reactivity of pigeon liver malic enzyme is also discussed.


Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6864
Author(s):  
Vladimir Burilov ◽  
Diana Mironova ◽  
Elsa Sultanova ◽  
Ramila Garipova ◽  
Vladimir Evtugyn ◽  
...  

A new polymeric NHC carrier was synthesized by sequential supramolecular self-assembly and copper-catalyzed azide-alkyne cycloaddition (CuAAC) of amphiphilic imidazolium calix[4]arenes with octyl lipophilic fragments. Obtained polytriazole-imidazolium particles were found as monodisperse submicron particles, with the average diameter of 236 ± 34 nm and average molecular weight of 1380 ± 96 kDa. Successful CuAAC polymerization has been proved using IR spectroscopy and high-resolution ESI mass spectrometry. Polymeric particles, as well as aggregates made from precursor macrocycles, were decorated by Pd clusters (2 nm) for further catalytic investigations. Pd nanoclusters, supported on the polymeric surface, were found highly catalytically active in the model reduction of p-nitrophenol, giving reaction rates an order of magnitude higher compared to literature examples. The reaction was recycled using the same catalyst five times without any loss of activity.


RSC Advances ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 1481-1492 ◽  
Author(s):  
M. Hitrik ◽  
Y. Sasson

To explain the decay of the activity of Ru-NPs catalysts, that formed in situ during allylic isomerization, we add a new step to a classic mechanism of transition-metal NPs self-assembly: the aggregation of two catalytically active NPs (C) to inactive bulk-metal (D).


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