Catalytic Function and Expression of Glutathione Transferase Zeta

The zeta class of glutathione S -transferases (GSTZ) is one of the most recently discovered soluble GST classes and has proved to be of considerable interest because of its contribution to the catabolism of phenylalanine and tyrosine and its role in α-halo acid metabolism. GSTZ was originally discovered as a result of a bioinformatic approach to gene discovery in the mid-1990s. This approach and others have also led to the discovery of several polymorphic forms of GSTZ. This chapter summarizes methods and approaches that have been used to express recombinant GSTZ, determine its crystal structure, measure its activity and characterize its kinetic properties, and study the function and importance of GSTZ in the metabolism of dichloroacetate (DCA), which is of great toxicological and public health interest. DCA is a multisite toxicant and carcinogen that is a byproduct of water chlorination and is a breakdown product of the industrial chemical and environmental contaminant trichloroethylene.