Thioltransferase can utilize cysteamine as same as glutathione as a reductant during the restoration of cystamine-treated glucose 6-phosphate dehydrogenase activity.

Glucose 6-phosphate dehydrogenase (G6PD) [EC 1.1.1.49] is inactivated by the incubation with cystamine very efficiently, but not by oxidized glutathione. This inactivation advanced following the incubation-time and concentration of cystamine. The inactivated-G6PD is restored its activity by the treatment of thioltransferase with 1 mM cysteamine or reduced glutathione (GSH) much more effectively than only by thiols. For the first time, we suggested thioltransferase can utilize cysteamine in stead of GSH during its thiol/disulfide exchange reaction activity.