Inhibition of human glutathione transferases by pesticides: Development of a simple analytical assay for the quantification of pesticides in water

Abstract

a b s t r a c tGlutathione transferases (GSTs; EC 2.5.1.18) form a group of multifunctional enzymes that are involved in phase II cellular detoxification mechanism. Here, screening of the inhibition potency of a wide range of pesticides toward selected human GST isoenzymes (hGSTA1-1, hGSTP1-1, hGSTT2-2 and hGSTO1-1) was carried out. hGSTA1-1 was found more susceptible to inhibition by pesticides than other isoenzymes. The insecticides dieldrin and spiromesifen were identified as potent reversible inhibitors toward hGSTA1-1 with IC 50 values equal to 17.9 ± 1.7 M and 12.1 ± 3.4 M, respectively. Based on in silico docking analysis and kinetic inhibition studies it was concluded that dieldrin and spiromesifen bind specifically to the enzyme presumably at a distinct position that partially overlaps with both the G-and H-site. The ability of dieldrin and spiromesifen to inhibit hGSTA1-1 activity was exploited for the development of analytical quantification assays for these two pesticides. Linear calibration curves were obtained for dieldrin and spiromesifen, with useful concentration in the range of 0-10 M. The reproducibility of the assay response, expressed by relative standard deviation, was in the order of 4.1% (N = 28). The method was successfully applied to the determination of these pesticides in real water samples without sample preparation steps.

Cytotoxic and genotoxic effects of abamectin, chlorfenapyr, and imidacloprid on CHOK1 cells

“…With all tested pesticides, the ameliorative effect of vitamin E was clear; it increased the GST activity to levels close to that of antioxidant-free control. GST plays a key role in the cellular detoxification of endogenous and xenobiotic chemicals (Chronopouloua et al 2012). Inhibition and induction of human and animal GST by pesticides have been reported (Ezemonye and Tongo 2010;Chronopouloua et al 2012); the differential alteration in the GST activity is pesticide-and tissue-specific (Ezemonye and Tongo 2010).…”

“…GST plays a key role in the cellular detoxification of endogenous and xenobiotic chemicals (Chronopouloua et al 2012). Inhibition and induction of human and animal GST by pesticides have been reported (Ezemonye and Tongo 2010;Chronopouloua et al 2012); the differential alteration in the GST activity is pesticide-and tissue-specific (Ezemonye and Tongo 2010). Abamectin and chlorfenapyr significantly increased the glutathione content; the presence of vitamin C ameliorated this effect.…”

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

“…The ability of GSTs to conjugate GSH with xenobiotics has been exploited for the development of enzyme-based biosensors for the determination and monitoring of such compounds in biological and environmental samples [16][17][18][19][20][21][22]. A range of different GST isoenzymes has been used so far for the fabrication of optical, electrochemical or potentiometric biosensors for measuring pesticides, such as the herbicide atrazine [16], the insecticides DDT [17], malathion [18], dieldrin and spiromesifen [19], α-endosulfan [20], and molinate [21]. In addition, a GST-based biosensor has been developed for the determination of anticancer drugs [23].…”

Expanding the Plant GSTome Through Directed Evolution: DNA Shuffling for the Generation of New Synthetic Enzymes With Engineered Catalytic and Binding Properties

“…The wide catalytic capabilities of GSTs along with their ideal structural features, such as stability, efficient heterologous expression in E. coli and purification by a single-step affinity chromatography have encouraged their exploitation in different areas of biotechnology (Perperopoulou et al, 2018 ). For example, selected GST isoenzymes are being exploited for the assembly of enzyme biosensors, which can find application in the measurements of xenobiotics, such as drugs, toxins, and herbicides (Kapoli et al, 2008 ; Chronopoulou et al, 2012b ; Oliveira et al, 2013 ; Materon et al, 2014 ). Furthermore, GSTs have been used in nanobiotechnology for the construction of biochips (Voelker and Viswanathan, 2013 ; Zhang et al, 2013 ; Zhou et al, 2014 ), nanowires and nanorings (Bai et al, 2013 ; Hou et al, 2013 ).…”