The enzyme, characterized from the plant Lepidium sativum, is involved in the breakdown of the glucosinolate glucotropaeolin. Depending on the substrate, it can also form simple nitrile- and epithionitrile-containing products. cf. EC 4.8.1.5, thiohydroximate-O-sulfate sulfate/sulfur-lyase (nitrile-forming), and EC 4.8.1.6, N-(sulfonatooxy)alkenimidothioic acid sulfate-lyase (epithionitrile-forming).