Proposed intracellular regulatory functions of glutathione transferases by recognition and binding to S-glutathiolated proteins.

A general reaction scheme is considered in which structurally diverse compounds can enhance transcription of glutathione S-transferase (GST) genes. Many of those compounds have the capacity to promote S-glutathiolation reactions with cysteine residues of proteins. The binding sites of GSTs, which are highly specific for binding of the tripeptide glutathione (GSH), can accommodate many structurally different substituents linked to GSH. Accordingly, it is suggested that GSH transferases can function by stoichiometric binding to S-glutathiolated proteins that are generated by oxidative stress or by reactive compounds. Binding to a GST could influence properties and regulate cellular functions of those proteins.