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 K_i 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

Keywords:

• Vaccinium arctostapylous L.
• GST enzyme
• metals
• chemicals
• inhibition
• molecular docking

Disclosure statement

The authors declare that there are no conflicts of interest.