School Of Basic And Applied Sciences

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Author: search.filters.author.Singh A.Has files: Yes

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    Insights into the Molecular Mechanism of Arsenic Phytoremediation
    (Springer New York LLC, 2019) Thakur S.; Choudhary S.; Majeed A.; Singh A.; Bhardwaj P.
    Arsenic (As) is a widespread carcinogenic pollutant. Phytoremediation is the most suited technology for alleviating the As contamination of soil. In this review, we have discussed the uptake mechanism and the associated transporters for different As species. Glutathione, phytochelatins, metallothionins, and secondary metabolites play important role in As detoxification and enhancing tolerance. The roles of MAPK signaling and calcium signaling are highlighted in the perception of As stress along with phytohormones signaling in stress tolerance. Furthermore, transcription factors involved in regulation of gene expression under As stress are discussed. High-throughput sequencing has reduced the time duration and enhanced the knowledge regarding understanding the molecular mechanism of phytoremediation. The role of CRISPR/Cas9 and synthetic genes in context to phytoremediation is discussed. We have provided a holistic understanding of the present knowledge about phytoremediation in the context of mechanisms of the As uptake and tolerance. A complete understanding of the phytoremediation process is essential for As-risk mitigation and will help in augmenting its efficiency and true potential.
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    Effect of arsenate substitution on phosphate repository of cell: A computational study
    (Royal Society Publishing, 2018) Singh A.; Giri K.
    The structural analogy with phosphate derives arsenate into various metabolic processes associated with phosphate inside the organisms. But it is difficult to evaluate the effect of arsenate substitution on the stability of individual biological phosphate species, which span from a simpler monoester form like pyrophosphate to a more complex phosphodiester variant like DNA. In this study, we have classified the physiological phosphate esters into three different classes on the basis of their structural differences. This classification has helped us to present a concise theoretical study on the kinetic stability of phosphate analogue species of arsenate against hydrolysis. All the calculations have been carried out using QM/MM methods of our Own N-layer Integrated molecular Orbital molecular Mechanics (ONIOM). For quantum mechanical region, we have used M06-2X density functional with 6-31+G(2d,2p) basis set and for molecular mechanics we have used the AMBER force field. The calculated rate constants for hydrolysis show that none of the phosphate analogue species of arsenate has a reasonable stability against hydrolysis.