Phytochelatins, the heavy-metal binding peptides of plants, are synthesised from glutathione by a specific γ-glutamylcysteine dipeptidyl transpeptidase (phytochelatine synthase). - Grill,E..; Löffler,S..; Winnacker,E.-L..; Zenk,M..H.. (Proceedings of the National Academy of Sciences of the USA, 1989)