THIOLTRANSFERASE ACTIVITY OF BOVINE LENS GLUTATHIONE-S-TRANSFERASE

A Mu-class glutathione S-transferase purified to electrophoretic homog eneity from bovine lens displayed thioltransferase activity, catalysin g the transthiolation reaction between GSH and hydroxyethyldisulphide. The thiol-transfer reaction is composed of two steps, the formation o f GSSG occurring through the generation of an intermediate mixed disul phide between GSH and the target disulphide. Unlike glutaredoxin, whic h is only able to catalyse the second step of the transthiolation proc ess, glutathione S-transferase catalyses both steps of the reaction. D ata are presented showing that bovine lens glutathione S-transferase a nd rat liver glutaredoxin, which was used as a thioltransferase enzyme model, can operate in synergy to catalyse the GSH-dependent reduction of hydroxyethyldisulphide.