Subcellular localization of O-acetylserine sulfhydrylase in spinach leaves

A combination of differential centrifugation and isopycnic sucrose density gradient centrifugation of extracts from spinach leaves (Spinacia oleracea L.) shows that about 20% of the O-Acetylserine sulfhydrylase are associated with chloroplasts. No appreciable amounts of O-Acetylserine sulfhydrylase band with mitochondrial and peroxisomal marker enzymes.