Electrochemical Detection of Glutathione S-Transferase: An Important Enzyme in the Cell Protective Mechanism Against Oxidative Stress

Abstract

Oxidative stress arises when the antioxidant capacity of cells to clean the excess production of reactive oxygen species (ROS) decreases. Several human diseases seem to be related with an increment in the oxidative stress. In this regard, GSH present in the cells works by neutralizing ROS and other xenobiotics through the glutathione S-transferase (GST) enzyme. Thus, the level of expression of GST is an important factor in determining the sensitivity of cells to toxic chemicals or xenobiotic compounds. Therefore, the detection of GST levels is fundamental in the clinical diagnosis of ROS-related diseases. Here, we describe a methodology, based on the voltammetric properties of the ferrocene group (used as electrochemical probe), which can be applied for selective detection of GST levels in human cells. The electrochemical signal measured is associated to the specific interaction of a ferrocenyl-GSH derivate with the G- and H-sites of this enzyme.

Electrochemical Methods for the Analysis of Clinically Relevant Biomolecules

“…Using the interaction between GST and ferrocene-labeled glutathione in solution, a voltammetric approach was developed for GST analysis . DPV voltammograms displayed a progressive decrease in the ferrocene peak current intensity as the GST concentration increased, reporting on the binding interaction between the electroactive ferrocene-labeled glutathione and GST.…”

Multivalent Lactose–Ferrocene Conjugates Based on Poly (Amido Amine) Dendrimers and Gold Nanoparticles as Electrochemical Probes for Sensing Galectin-3

“…Both electrodes were then sonicated in a 1:1:1 H 2 O/MeOH/CH 3 CN mixture for 5 min prior to use. The effective area of the electrodes was determined as previously reported [39]. and increasing amounts of Gal-3 varying from 0 to 45 µM were prepared in 10 mM phosphate buffer at pH 7.2 with 20 mM NaCl and incubated for 10 min at room temperature.…”

“…We previously reported on the redox and sensing ability properties of carbohydrate and peptide-ferrocene conjugates toward proteins [31][32][33][34][35][36][37][38][39]. An interesting finding was the fact that the multivalent presentation of ferrocene-mannose conjugates led to a remarkable enhancement of the protein sensing properties due to the multivalent glycoside effect and the multielectron exchange as a result of the multiple ferrocene units [36,38].…”

Multivalent Lactose–Ferrocene Conjugates Based on Poly(Amido Amine) Dendrimers and Gold Nanoparticles as Electrochemical Probes for Sensing Galectin-3

“…Both electrodes were then sonicated in a 1:1:1 H2O/MeOH/CH3CN mixture for 5 min prior to use. The effective area of the electrodes was determined as previously reported [39]. A Ag/AgCl (3 M KCl) electrode was used as a reference.…”