Picture from www.pdb.org

Locations:

Found in humans and is located in most tissues because of its glutathion-dependent thiol transferase and dehydroascorbate reductase activities (Board).

Thermodynamics:

At a pH of 6.5, protons were released from the GHT binding site. At temperatures between fifteen and thirty degrees Celsius, binding was not as successful. In one study, the thermodynamic parameters were set so that the Gibbs free energy was constant as a function of temperature. Here, enthalpy and entropy would decrease as temperature increased. It was found that the binding enthalpy was favored at all temperatures but at temperatures below 25 degrees Celsius, the contribution of entropy progressively decreased and eventually became unfavorable (Ortiz-Salmeron).

This enzyme is involved in the detoxification of the cell again toxic any carcinogenic compounds by catalyzing the nucleophilic attack on the electrophilic center. The function of this enzyme is to promote the conjugation of Sulfur atoms in Glutathione.

Other functions:

Peroxidase activity with organic peroxides

Possible role of "ligandins" (ligand carriers)

Other forms of cell defense (Lo-Bello)

Structure: Glutathione S-Transferase is a globular shape that contains 2 subunits. The structure of the subunits consist of 2 domains. Domain 1 is a smaller Alpha/Beta domain. Domain two is a larger, alpha domain. Domain one forms a central mixed beta sheet and three alpha-helices. They are arranged in a Beta, Alpha, Beta, Alpha organization. This domain is considered the glutathione binding domain. The second domain is composed of five alpha-helices. This domain is responsible for the xenobiotic (foreign to living organism) substrate binding (Xinhua Ji). This binding site is a hydrophobic cavity and is defined by the side chains from domain one to domain two. The active site is in the center of a 19-angstrom cavity and is made of 3 structural elements, a long loop, a helix-turn-helix segment, and the C-terminal tail. (Xinhua Ji)