Electrochemical detection of glutathione S-transferase: an important enzyme in the cell protective mechanism against oxidative stress.

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.