Reaction catalyzed by glutathione gamma-glutamylcysteinyltransferase (2.3.2.15)

		+			=			+
	S-ethylglutathione	+		[Glu(-Cys)]n-Gly	=		Gly	+		[Glu(-Cys)]n-Glu-S-ethyl-Cys-Gly