Conjugation of 2-chloroacetanilide herbicides with glutathione: role of molecular structures and of glutathione S-transferase enzymes

1991 ◽  
Vol 39 (11) ◽  
pp. 2010-2013 ◽  
Author(s):  
Luciano Scarponi ◽  
Piero Perucci ◽  
Luca Martientti
2020 ◽  
Author(s):  
Marc Philipp Bahlke ◽  
Natnael Mogos ◽  
Jonny Proppe ◽  
Carmen Herrmann

Heisenberg exchange spin coupling between metal centers is essential for describing and understanding the electronic structure of many molecular catalysts, metalloenzymes, and molecular magnets for potential application in information technology. We explore the machine-learnability of exchange spin coupling, which has not been studied yet. We employ Gaussian process regression since it can potentially deal with small training sets (as likely associated with the rather complex molecular structures required for exploring spin coupling) and since it provides uncertainty estimates (“error bars”) along with predicted values. We compare a range of descriptors and kernels for 257 small dicopper complexes and find that a simple descriptor based on chemical intuition, consisting only of copper-bridge angles and copper-copper distances, clearly outperforms several more sophisticated descriptors when it comes to extrapolating towards larger experimentally relevant complexes. Exchange spin coupling is similarly easy to learn as the polarizability, while learning dipole moments is much harder. The strength of the sophisticated descriptors lies in their ability to linearize structure-property relationships, to the point that a simple linear ridge regression performs just as well as the kernel-based machine-learning model for our small dicopper data set. The superior extrapolation performance of the simple descriptor is unique to exchange spin coupling, reinforcing the crucial role of choosing a suitable descriptor, and highlighting the interesting question of the role of chemical intuition vs. systematic or automated selection of features for machine learning in chemistry and material science.


2019 ◽  
Vol 24 (39) ◽  
pp. 4659-4667 ◽  
Author(s):  
Mona Fani ◽  
Milad Zandi ◽  
Majid Rezayi ◽  
Nastaran Khodadad ◽  
Hadis Langari ◽  
...  

MicroRNAs (miRNAs) are non-coding RNAs with 19 to 24 nucleotides which are evolutionally conserved. MicroRNAs play a regulatory role in many cellular functions such as immune mechanisms, apoptosis, and tumorigenesis. The main function of miRNAs is the post-transcriptional regulation of gene expression via mRNA degradation or inhibition of translation. In fact, many of them act as an oncogene or tumor suppressor. These molecular structures participate in many physiological and pathological processes of the cell. The virus can also produce them for developing its pathogenic processes. It was initially thought that viruses without nuclear replication cycle such as Poxviridae and RNA viruses can not code miRNA, but recently, it has been proven that RNA viruses can also produce miRNA. The aim of this articles is to describe viral miRNAs biogenesis and their effects on cellular and viral genes.


Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 649
Author(s):  
Marco Capolupo ◽  
Paola Valbonesi ◽  
Elena Fabbri

The ocean contamination caused by micro- and nano-sized plastics is a matter of increasing concern regarding their potential effects on marine organisms. This study compared the effects of a 21-day exposure to 1.5, 15, and 150 ng/L of polystyrene microplastics (PS-MP, 3-µm) and nanoplastics (PS-NP, 50-nm) on a suite of biomarkers measured in the Mediterranean mussel Mytilus galloprovincialis. Endpoints encompassed immunological/lysosomal responses, oxidative stress/detoxification parameters, and neurotoxicological markers. Compared to PS-MP, PS-NP induced higher effects on lysosomal parameters of general stress. Exposures to both particle sizes increased lipid peroxidation and catalase activity in gills; PS-NP elicited greater effects on the phase-II metabolism enzyme glutathione S-transferase and on lysozyme activity, while only PS-MP inhibited the hemocyte phagocytosis, suggesting a major role of PS particle size in modulating immunological/detoxification pathways. A decreased acetylcholinesterase activity was induced by PS-NP, indicating their potential to impair neurological functions in mussels. Biomarker data integration in the Mussel Expert System identified an overall greater health status alteration in mussels exposed to PS-NP compared to PS-MP. This study shows that increasing concentrations of nanoplastics may induce higher effects than microplastics on the mussel’s lysosomal, metabolic, and neurological functions, eventually resulting in a greater impact on their overall fitness.


1995 ◽  
Vol 268 (1) ◽  
pp. H278-H287 ◽  
Author(s):  
S. J. Elliott ◽  
T. N. Doan ◽  
P. N. Henschke

Oxidant stress mediated by tert-butyl hydroperoxide (t-BOOH) inhibits agonist-stimulated Ca2+ entry and internal store Ca2+ release in cultured endothelial cells. The role of intracellular glutathione in modulating the effects of oxidant stress on Ca2+ signaling was determined in cells preincubated with buthionine-[S,R]-sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, or 1-chloro-2,4-dinitrobenzene (CDNB), a cosubstrate for glutathione-S-transferase. BSO and CDNB decreased endothelial cell glutathione content by 85 and 97%, respectively (control glutathione, 21.5 +/- 2.3 nmol/mg protein). Each agent accelerated the time-dependent effects of t-BOOH on Ca2+ signaling in fura 2-loaded cells and potentiated the inhibition of bradykinin-stimulated 45Ca2+ efflux induced by t-BOOH. These results indicate that decreased availability of reduced glutathione, the primary cosubstrate for glutathione peroxidase, potentiates the effect of hydroperoxide oxidant stress on receptor-operated Ca2+ entry across the plasmalemma and Ca2+ release from internal stores. The present findings suggest that intracellular glutathione availability and/or glutathione redox cycle activity are critically important modulators of oxidant inhibition of Ca(2+)-dependent signal transduction.


Biochimie ◽  
2008 ◽  
Vol 90 (6) ◽  
pp. 968-971 ◽  
Author(s):  
Carmen A. Contreras-Vergara ◽  
Elisa M. Valenzuela-Soto ◽  
Aldo A. Arvizu-Flores ◽  
Rogerio R. Sotelo-Mundo ◽  
Gloria Yepiz-Plascencia

Biomics ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 20-26
Author(s):  
D.R. Maslennikova ◽  
F.M. Shakirova

The study carried out a comparative analysis of the effect of 24 epibrassinolide (EB) and 6-benzylaminopurine (BAP) on the growth and state of the main components of the glutathione system in the roots of wheat seedlings under the action of 2% NaCl, which for the first time revealed the ability of these phytohormones to similarly stabilize stress-induced decrease GSH / GSSG ratio, positively regulate the activity of glutathione reductase and glutathione-S-transferase. A comparable level of protective effect of BAP and EB on root length was revealed. The data obtained indicate that endogenous cytokinins may play the role of hormonal intermediates in the implementation of the protective.


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