Function
Exhibits a very robust glutathione (GSH)-dependent disulfide-bond reductase activity toward the model substrate, 2-hydroxyethyl disulfide; the actual physiological substrates are not known. Has also a low GSH-dependent hydroperoxidase activity toward cumene hydroperoxide, but does not reduce H(2)O(2), tert-butyl hydroperoxide, benzyl peroxide, or lauroyl peroxide. Exhibits little or no GSH transferase activity with most typical electrophilic substrates, and has no detectable transferase activity using glutathionylspermidine (GspSH) as the nucleophilic substrate. Is involved in defense against oxidative stress, probably via its peroxidase activity.