Plant Glutathione Transferases: Structure, Antioxidant Catalytic Function and in planta Protective Role in Biotic and Abiotic Stress

Chronopoulou, Evangelia; Kontouri, Kassiani G.; Chantzikonstantinou, Marianna; Pouliou, Fotini; Perperopoulou, Fereniki; Voulgari, Georgia; Bosmali, Eirini; Axarli, Irene; Nianiou-Obeidat, Irini; Madesis, Panagiotis; Tsaftaris, Athanasios; Labrou, Nikolaos E.

doi:10.2174/2212796809666150302213733

Cited by 12 publications

(5 citation statements)

References 100 publications

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“…Several crystallographic studies have demonstrated that GSTs are dimeric proteins. In each subunit, two distinct binding sites are located: one for the glutathione (G-site) and the other for the electrophilic substrate (H-site) [7,8]. Human cytosolic GSTs are classified into seven classes, namely alpha (A), zeta (Z), theta (T), mu (M), pi (P), sigma (S), and omega (O) [9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Monocarbonyl Curcumin Analogues as Potent Inhibitors against Human Glutathione Transferase P1-1

et al. 2022

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The isoenzyme of human glutathione transferase P1-1 (hGSTP1-1) is involved in multi-drug resistance (MDR) mechanisms in numerous cancer cell lines. In the present study, the inhibition potency of two curcuminoids and eleven monocarbonyl curcumin analogues against hGSTP1-1 was investigated. Demethoxycurcumin (Curcumin II) and three of the monocarbonyl curcumin analogues exhibited the highest inhibitory activity towards hGSTP1-1 with IC50 values ranging between 5.45 ± 1.08 and 37.72 ± 1.02 μM. Kinetic inhibition studies of the most potent inhibitors demonstrated that they function as non-competitive/mixed-type inhibitors. These compounds were also evaluated for their toxicity against the prostate cancer cells DU-145. Interestingly, the strongest hGSTP1-1 inhibitor, (DM96), exhibited the highest cytotoxicity with an IC50 of 8.60 ± 1.07 μΜ, while the IC50 values of the rest of the compounds ranged between 44.59–48.52 μΜ. Structural analysis employing molecular docking, molecular dynamics (MD) simulations, and binding-free-energy calculations was performed to study the four most potent curcumin analogues as hGSTP1-1 inhibitors. According to the obtained computational results, DM96 exhibited the lowest binding free energy, which is in agreement with the experimental data. All studied curcumin analogues were found to form hydrophobic interactions with the residue Gln52, as well as hydrogen bonds with the nearby residues Gln65 and Asn67. Additional hydrophobic interactions with the residues Phe9 and Val36 as well as π–π stacking interaction with Phe9 contributed to the superior inhibitory activity of DM96. The van der Waals component through shape complementarity was found to play the most important role in DM96-inhibitory activity. Overall, our results revealed that the monocarbonyl curcumin derivative DM96 acts as a strong hGSTP1-1 inhibitor, exerts high prostate cancer cell cytotoxicity, and may, therefore, be exploited for the suppression and chemosensitization of cancer cells. This study provides new insights into the development of safe and effective GST-targeted cancer chemosensitizers.

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Section: Introductionmentioning

confidence: 99%

Monocarbonyl Curcumin Analogues as Potent Inhibitors against Human Glutathione Transferase P1-1

et al. 2022

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“…They catalyze the conjugation of glutathione (GSH) with a range of hydrophobic xenobiotic compounds such as drugs, environmental pollutants, and pesticides, including chloroacetanilide herbicides [3][4][5][6][7][8][9]. Their catalytic versatility and wide-substrate specificity stem from their structural flexibility and active-site plasticity [3,[10][11][12][13]. They are homodimers or heterodimers.…”

Section: Introductionmentioning

confidence: 99%

Directed Evolution of a Glutathione Transferase for the Development of a Biosensor for Alachlor Determination

et al. 2021

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In the present work, DNA recombination of three homologous tau class glutathione transferases (GSTUs) allowed the creation of a library of tau class GmGSTUs. The library was activity screened for the identification of glutathione transferase (GST) variants with enhanced catalytic activity towards the herbicide alachlor (2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide). One enzyme variant (GmGSTsf) with improved catalytic activity and binding affinity for alachlor was identified and explored for the development of an optical biosensor for alachlor determination. Kinetics analysis and molecular modeling studies revealed a key mutation (Ile69Val) at the subunit interface (helix α3) that appeared to be responsible for the altered catalytic properties. The enzyme was immobilized directly on polyvinylidenefluoride membrane by crosslinking with glutaraldehyde and was placed on the inner surface of a plastic cuvette. The rate of pH changes observed as a result of the enzyme reaction was followed optometrically using a pH indicator. A calibration curve indicated that the linear concentration range for alachlor was 30–300 μM. The approach used in the present study can provide tools for the generation of novel enzymes for eco-efficient and environment-friendly analytical technologies. In addition, the outcome of this study gives an example for harnessing protein symmetry for enzyme design.

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“…Of all plant GSH-related enzymes, the GST superfamily is especially large and diverse [49,50]. Soluble GSTs are typically dimers of 24-27 kDa subunits, with isoelectric points near pH 5 [31].…”

Section: Discussionmentioning

confidence: 99%

Proteomic and biochemical assays of glutathione-related proteins in susceptible and multiple herbicide resistant Avena fatua L.

Burns

Keith

Refai

et al. 2017

Pesticide Biochemistry and Physiology

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Extensive herbicide usage has led to the evolution of resistant weed populations that cause substantial crop yield losses and increase production costs. The multiple herbicide resistant (MHR) Avena fatua L. populations utilized in this study are resistant to members of all selective herbicide families, across five modes of action, available for A. fatua control in U.S. small grain production, and thus pose significant agronomic and economic threats. Resistance to ALS and ACCase inhibitors is not conferred by target site mutations, indicating that non-target site resistance mechanisms are involved. To investigate the potential involvement of glutathione-related enzymes in the MHR phenotype, we used a combination of proteomic, biochemical, and immunological approaches to compare their constitutive activities in herbicide susceptible (HS1 and HS2) and MHR (MHR3 and MHR4) A. fatua plants. Proteomic analysis identified three tau and one phi glutathione S-transferases (GSTs) present at higher levels in MHR compared to HS plants, while immunoassays revealed elevated levels of lambda, phi, and tau GSTs. GST specific activity towards 1-chloro-2,4-dinitrobenzene was 1.2-fold higher in MHR4 than in HS1 plants and 1.3- and 1.2-fold higher in MHR3 than in HS1 and HS2 plants, respectively. However, GST specific activities towards fenoxaprop-P-ethyl and imazamethabenz-methyl were not different between untreated MHR and HS plants. Dehydroascorbate reductase specific activity was 1.4-fold higher in MHR than HS plants. Pretreatment with the GST inhibitor NBD-Cl did not affect MHR sensitivity to fenoxaprop-P-ethyl application, while the herbicide safener and GST inducer mefenpyr reduced the efficacy of low doses of fenoxaprop-P-ethyl on MHR4 but not MHR3 plants. Mefenpyr treatment also partially reduced the efficacy of thiencarbazone-methyl or mesosulfuron-methyl on MHR3 or MHR4 plants, respectively. Overall, the GSTs described here are not directly involved in enhanced rates of fenoxaprop-P-ethyl or imazamethabenz-methyl metabolism in MHR A. fatua. Instead, we propose that the constitutively elevated GST proteins and related enzymes in MHR plants are representative of a larger, more global suite of abiotic stress-related changes.

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Plant Glutathione Transferases: Structure, Antioxidant Catalytic Function and in planta Protective Role in Biotic and Abiotic Stress

Cited by 12 publications

References 100 publications

Monocarbonyl Curcumin Analogues as Potent Inhibitors against Human Glutathione Transferase P1-1

Monocarbonyl Curcumin Analogues as Potent Inhibitors against Human Glutathione Transferase P1-1

Directed Evolution of a Glutathione Transferase for the Development of a Biosensor for Alachlor Determination

Proteomic and biochemical assays of glutathione-related proteins in susceptible and multiple herbicide resistant Avena fatua L.

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