Glucosinolate Biosynthesis

Abstract
After removal of myrosinase activity by concanavalin A-Sepharose 4B chromatography, cell-free extracts of light-grown cress (Lepidium sativum L.) seedlings, catalyzed the sulfation of desulfobenzylglucosinolate (Km, 0.23 millimolar) to benzylglucosinolate using PAPS (Km, 1 millimolar) as sulfur donor. Sulfotransferase activity, which was optimal at pH 9.0, was stimulated by MgCl2, MnCl2, .beta.-mercaptoethanol, and dithiothreitol and was inhibited by ZnSO4 and SH-reagents. The enzyme also sulfated desulfoallylglucosinolate to allylglucosinolate (sinigrin) but was inactive towards all phenylpropanoids and flavonoids tested.