In vitro and in silico enzyme inhibition effects of some metal ions and compounds on glutathione S-transferase enzyme purified from Vaccinium arctostapylous L

Abstract

Glutathione s-transferase (GST) is a class of enzymes that performs a wide array of biological functions. However, GST enzymes are most famously known for their roles in catalyzing the conjugation of reduced glutathione (GSH) to electrophilic centers on a wide variety of substrates to induce water-solubility to compounds as a protective antioxidant mechanism against toxic substances. In the present study, in vitro inhibition effects of coumarin, ascorbic acid, sodium sulfide, sodium azide, citric acid compounds, and Cd2+, Cu2+, Ni2+, Mg2+ metal ions against GST enzyme were determined. For this aim, the GST enzyme was purified from Vaccinium arctostapylous L. using the glutathione-agarose affinity chromatography and Sephadex G-100 gel filtration steps. The respective metals and chemical compounds were used at different concentrations for measuring their in vitro GST activity effects. The Ki values of these agents were determined as 0.450 ± 0.13, 15.05 ± 7.05, 0.009 ± 0.001, 0.022 ± 0.006, 0.120 ± 0.36, 0.150 ± 0.06, 0.223 ± 0.03, 0.002 ± 0.0003, and 0.136 ± 0.06 mM, respectively. Finally, the molecular docking interactions of the compounds with the GST target enzyme were evaluated using Autodock Tools-1.5.6. The effective molecular interactions of coumarin, citric acid, ascorbic acid, and sodium sulfide with GST target enzyme were found with their binding lowest energy affinities -4.62, -3.04, -2.53, and -1.67 kcal/mol, respectively.Communicated by Ramaswamy H. Sarma.