Structure-Guided Mechanisms Behind the Metabolism of 2,4,6-Trinitrotoluene by Glutathione Transferases U25 and U24 That Lead to Alternate Product Distribution

Tzafestas, Kyriakos; Ahmad, Laziana; Dani, Mária; Grogan, Gideon; Rylott, Elizabeth L.; Bruce, Neil C.

doi:10.3389/fpls.2018.01846

Cited by 11 publications

(4 citation statements)

References 45 publications

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“…The main cis-regulatory elements found in the 5' up-regulatory region of the genes are rather different, although both genes contain several presumably abiotic stress-and hormone-inducible sequences (Table S2). The AtGSTU19 represents a significant percentage of the GST pool in Arabidopsis [26], while AtGSTU24 came to the forefront especially according to its detoxification ability [9,45]. Both isoenzymes may have a role in salt stress responses and possess high activity toward the CDNB substrate [5,11,46].…”

Section: Arabidopsis Plants Compensated For the Decreased Atgstu Tranmentioning

confidence: 99%

Compensation of Mutation in Arabidopsis glutathione transferase (AtGSTU) Genes under Control or Salt Stress Conditions

Horváth

Bela

Gallé

et al. 2020

IJMS

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Glutathione transferases (GSTs) play a crucial role in detoxification processes due to the fact of their glutathione (GSH) conjugating activity, and through glutathione peroxidase or dehydroascorbate reductase (DHAR) activities, they influence the redox state of GSH and ascorbate (AsA). The plant-specific tau (GSTU) group is the largest class of Arabidopsis GSTs, and their members are involved in responses to different abiotic stresses. We investigated the effect of salt stress on two-week-old Arabidopsis thaliana wild-type (Col-0), Atgstu19 and Atgstu24 mutant plants after applying 150 mM NaCl for two days. The Atgstu19 seedlings had lower GST activity and vitality both under control conditions and after salt stress than the wild-type, but the level of total ROS was similar to the Col-0 plants. The GST activity of the knockout Atgstu24 mutant was even higher under control conditions compared to the Col-0 plants, while the ROS level and its vitality did not differ significantly from the wild-type. Analysis of the AtGSTU expression pattern revealed that the mutation in a single AtGSTU gene was accompanied by the up- and downregulation of several other AtGSTUs. Moreover, elevated AsA and GSH levels, an altered GSH redox potential and increased DHAR and glutathione reductase activities could help to compensate for the mutation of AtGSTU genes. The observed changes in the mutants suggest that the investigated isoenzymes influence the redox homeostasis under control conditions and after NaCl treatment in Arabidopsis seedlings. These data indicate for the first time the more general role of a temporary shift of redox status as part of GST mechanisms and regulation.

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Section: Arabidopsis Plants Compensated For the Decreased Atgstu Tranmentioning

confidence: 99%

Compensation of Mutation in Arabidopsis glutathione transferase (AtGSTU) Genes under Control or Salt Stress Conditions

Horváth

Bela

Gallé

et al. 2020

IJMS

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“…In conclusion, the possible mechanism of Meisenheimer–dihydride complexes of TNT from the metabolism of several flavoprotein reductases (or microorganisms) is fully explored in detail. 28 It is of great significance for the design and development of new technologies that can fully degrade the nitro aromatic explosives.…”

Section: Discussionmentioning

confidence: 99%

A Density Functional Theory Study toward Ring-Opening Reaction Mechanisms of 2,4,6-Trinitrotoluene’s Meisenheimer Complex for the Biodegradation of Old Yellow Enzyme Flavoprotein Reductase

et al. 2020

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The subsequent degradation pathway of the dihydride–Meisenheimer complex (2H––TNT), which is the metabolite of 2,4,6-trinitrotoluene (TNT) by old yellow enzyme flavoprotein reductases of yeast and bacteria, was investigated computationally at the SMD/TPSSH/6-311+G(d,p) level of theory. Combining the experimentally detected products, a series of protonation, addition, substitution (dearomatization), and ring-opening reaction processes from 2H––TNT to alkanes were proposed. By analyzing reaction free energies, we determined that the protonation is more advantageous thermodynamically than the dimerization reaction. In the ring-opening reaction of naphthenic products, the water molecule-mediated proton transfer mechanism plays a key role. The corresponding activation energy barrier is 37.7 kcal·mol–1, which implies the difficulty of this reaction. Based on our calculations, we gave an optimum pathway for TNT mineralization. Our conclusions agree qualitatively with available experimental results. The details on transition states, intermediates, and free energy surfaces for all proposed reactions are given and make up for a lack of experimental knowledge.

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“…Tzafestas et al [64] found that GSTU24 and GSTU25 genes in A. thaliana can catalyze glutathione coupling with 2,4,6-trinitrotoluene (TNT). These results indicate that glutathione s-transferase can directly or indirectly bind to pollutants, thereby reducing the damage that pollutants induce in plants.…”

Section: Gst Activity Towards Guanidine Thiocyanate In Vitromentioning

confidence: 99%

Recombinant expression of Thermosynechococcus elongatus BP-1 glutathione S-transferase in Arabidopsis thaliana: an efficient tool for phytoremediation of thiocyanate

Gao

Zhang

Peng

et al. 2020

Biotechnology & Biotechnological Equipment

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Large-scale production of thiocyanate (SCN -) for industrial purposes has led to widespread environmental pollution by this compound. Thiocyanate (SCN -) is toxic for humans and recalcitrant to biological oxygenation and hydrolysis. Phytoremediation is an effective technique for disposal of SCNbecause thiocyanate (SCN -) can be assimilated by many plants from contaminated water and soil. In this study, we demonstrate that Thermosynechococcus elongatus BP-1 glutathione S-transferase (TeGST) is a good candidate gene for enhancing phytoremediation of thiocyanate (SCN -) in the plant. Our study demonstrated that Arabidopsis thaliana introduced with the glutathione S-transferase (GST) gene were able to germinate and grow in a medium containing 5 mmol L À1 thiocyanate (SCN -), which was lethal for wild-type plants. Moreover, the GST can confer the capacity of plants to remove more thiocyanate in vivo. Our results suggest that grafting the T. elongatus BP-1 glutathione S-transferase (TeGST) gene into plants is a potentially effective strategy to enhance phytoremediation of environmental thiocyanates. To our knowledge, this is the first study on the degradation of guanidine isothiocyanate by transgenic plants.

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Structure-Guided Mechanisms Behind the Metabolism of 2,4,6-Trinitrotoluene by Glutathione Transferases U25 and U24 That Lead to Alternate Product Distribution

Cited by 11 publications

References 45 publications

Compensation of Mutation in Arabidopsis glutathione transferase (AtGSTU) Genes under Control or Salt Stress Conditions

Compensation of Mutation in Arabidopsis glutathione transferase (AtGSTU) Genes under Control or Salt Stress Conditions

A Density Functional Theory Study toward Ring-Opening Reaction Mechanisms of 2,4,6-Trinitrotoluene’s Meisenheimer Complex for the Biodegradation of Old Yellow Enzyme Flavoprotein Reductase

Recombinant expression of Thermosynechococcus elongatus BP-1 glutathione S-transferase in Arabidopsis thaliana: an efficient tool for phytoremediation of thiocyanate

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