REDUCTION OF A TRISULFIDE DERIVATIVE OF GLUTATHIONE BY GLUTATHIONE-REDUCTASE

Glutathione trisulfide was synthesized from glutathione disulfide and its reduction by glutathione reductase was studied. A two-step reactio n was observed. In a first step, the rate of reduction was similar to that observed with glutathione disulfide. In addition to glutathione, a persulfide intermediate was detected by an electrochemical method an d was carboxymethylated by iodoacetate to be identified by Plasma Deso rption Mass Spectrometry. During the second step the reduction of this intermediate led to the formation of hydrogen sulfide and a second eq uivalent of glutathione. (C) 1994 Academic Press, Inc.