Role of Renshaw Cells in the Mammalian Locomotor Circuit: A Computational Study

Author(s):  
Priscilla Corsi ◽  
Emanuele Formento ◽  
Marco Capogrosso ◽  
Silvestro Micera
Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4083
Author(s):  
Heming Jiang ◽  
Tian-Yu Sun

A computational study on the origin of the activating effect for Pd-catalyzed directed C–H activation by the concerted metalation-deprotonation (CMD) mechanism is conducted. DFT calculations indicate that strong acids can make Pd catalysts coordinate with directing groups (DGs) of the substrates more strongly and lower the C–H activation energy barrier. For the CMD mechanism, the electrophilicity of the Pd center and the basicity of the corresponding acid ligand for deprotonating the C–H bond are vital to the overall C–H activation energy barrier. Furthermore, this rule might disclose the role of some additives for C–H activation.


Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1024
Author(s):  
Sebastien Dupont ◽  
Paul Fleurat-Lessard ◽  
Richtier Gonçalves Cruz ◽  
Céline Lafarge ◽  
Cédric Grangeteau ◽  
...  

Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl hydroperoxide and protects lipids against oxidation in liposomes. A computational study based on quantum chemistry revealed that this protection could be related to its antioxidant properties operating through an electron transfer followed by a proton transfer mechanism. This study demonstrates the antioxidant role of ergosterol and proposes knowledge elements to explain the specific accumulation of this sterol in late branching fungi. Ergosterol, as a natural antioxidant molecule, could also play a role in the incompletely understood beneficial effects of some mushrooms on health.


Author(s):  
Sascha Jähnigen ◽  
Daniel Sebastiani ◽  
Rodolphe Vuilleumier

We present a computational study of vibrational circular dichroism (VCD) in solutions of (S)-lactic acid, relying on ab initio molecular dynamics (AIMD) and full solvation with bulk water. We discuss...


2019 ◽  
Author(s):  
Alberto Capurro ◽  
Jack Thornton ◽  
Bruno Cessac ◽  
Lyle Armstrong ◽  
Evelyne Sernagor

This manuscript has been withdrawn by the authors as they no longer stand by part of their conclusions and wish not to be cited for this work. If you have any questions, please contact the corresponding authors.


2020 ◽  
Vol 10 (1) ◽  
pp. 4944-4955 ◽  

Alzheimer’s disease (AD) is characterized by the presence of Amyloid-beta (Aβ) peptide, which has the propensity to fold into β-sheets under stress forming aggregated amyloid plaques. Nowadays many studies have focused on the development of novel, specific therapeutic strategies to slow down Aβ aggregation or control preformed aggregates. Albumin, the most abundant protein in the cerebrospinal fluid, was reported to bind Aβ impeding its aggregation. Recently, it has been reported that C-terminal (CTerm) of Human Albumin binds with Aβ1-42, impairs Aβ aggregation and promotes disassembly of Aβ aggregates protecting neurons. In this computational study, we have investigated the effect of CTerm on the conformational dynamics and the aggregation propensity of Aβ1-42 peptide. We have performed molecular dynamics simulations on the Aβ1-42-Aβ1-42 homodimer and Aβ1-42-CTerm of albumin heterodimer using the AMBER force field ff99SBildn. From the Potential of mean force (PMF) study and Binding free energy (BFE) analysis, we observed the association of Aβ1-42 peptide monomer with itself in the form of homodimer to be stronger than its association with the CTerm in the heterodimer complex. The difference in the number of residues in the Aβ1-42 peptide monomer (42 AAs) and CTerm (35 AAs) may be probable reason for the difference in association between the monomeric units in corresponding homodimer and heterodimer complexes. But even then CTerm shows a significant effect on the dimerization of Aβ1-42 peptide. Our findings therefore suggest that CTerm can be used for the disassembly of Aβ1-42 peptide monomer.


Author(s):  
Chenhao Tu ◽  
Nana Ma ◽  
Qingli Xu ◽  
Wenyue Guo ◽  
Lanxin Zhou ◽  
...  

C-radical borylation is an significant approach for the construction of carbon−boron bond. Photochemical borylation of aryl halides successfully applied this strategy. However, precise mechanisms, such as the generation of aryl radicals and the role of base additive(TMDAM) and water, remain controversy in these reactions. In this study, photochemical borylation of aryl halides has been researched by density functional theory (DFT) calculations. Indeed, the homolytic cleavage of the C−X bond under irradiation with UV-light is a key step for generation of aryl radicals. Nevertheless, the generation of aryl radicals may also undergo the process of single electron transfer and the heterolytic carbon-halogen bond cleavage sequence, and the latter is favorable during the reaction.


2020 ◽  
Vol 11 (1) ◽  
pp. 257-263 ◽  
Author(s):  
Gianluca Casotti ◽  
Gianluca Ciancaleoni ◽  
Filippo Lipparini ◽  
Chiara Nieri ◽  
Anna Iuliano

The reaction mechanism of a new conjugate addition reaction of organozinc halides to enones is disclosed by a combined experimental/computational study.


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