Purification of glutathione S-transferase isoenzymes from tumour and nontumour human stomach and inhibitory effects of some heavy metals on enzymes activities

Abstract

In this study, glutathione S-transferase (GST) enzyme was purified from nontumour and tumour human gastric tissue and in vitro effects of heavy metals on the enzyme were examined. GST was purified 3089 fold with a specific activity of 20 U/mg and a yield of 78% from gastric tumour tissue; and 1185 fold with a specific activity of 5.69 U/mg and a yield of 50% from nontumour tissue by using glutathione−agarose affinity column, respectively. Enzyme purity was verified by SDS-PAGE and subunit molecular mass was calculated around 26 kDa. The molecular weight of the enzyme was calculated as 52 kDa by using Sephadex G-75 gel filtration column. Then, inhibitory effects of metal ions on the enzymes were investigated. Mg²⁺ and Cd²⁺ had inhibitory effect on the enzymes activities. Other kinetic properties of the enzymes were also determined.

Keywords::

• Cancer
• GST
• enzyme
• metal
• inhibition

Acknowledgements

Research ethics committee approval needed for the cancerous tissue used in this study was taken from Ataturk University, Faculty of Medicine.

Declaration of interest

The authors report no conflicts of interest.