Reaction catalyzed by prostamide/prostaglandin F2alpha synthase (1.11.1.20)

		+			=			+
	thioredoxin	+		(5Z,9alpha,11alpha,13E,15S)-9,11-epidioxy-15-hydroxy-prosta-5,13-dienoate	=		thioredoxin disulfide	+		(5Z,9alpha,11alpha,13E,15S)-9,11,15-trihydroxyprosta-5,13-dienoate