Glutathione S-conjugates stimulate ATP hydrolysis in the plasma membrane fraction of rat hepatocytes.

Incubation of a rat hepatocyte plasma membrane fraction with micromolar concentrations of either glutathione disulfide or various glutathione S-conjugates resulted in a several-fold increase in the rate of ATP hydrolysis. This stimulation was further enhanced when the plasma membrane fraction had been pretreated with agents that arylate or oxidize sulfhydryl groups, suggesting that this ATPase activity is modulated by the protein thiol status of the plasma membrane. It is proposed that this newly discovered ATPase may function in the cellular extrusion of both glutathione disulfide and glutathione S-conjugates.