title: Degradation of glutathione S-conjugates by a carboxypeptidase in the plant vacuole.
abstract: For plants, glutathione conjugation is a major pathway to detoxify organic xenobiotic. Glutathione S-conjugates (SG-conjugates) are formed in the cytosol, the in vitro transport over the tonoplast has been described and a final storage in the vacuole has been postulated. We show here that alachlor rapidly accumulates as GS-conjugates in the plant vacuole and that the first step of its degradation, the formation of the respective gamma-glutamylcysteinyl-S-conjugate, is catalyzed by a vacuolar carboxypeptidase. These results suggest the glutathione conjugate as a transport form but not a storage form of xenobiotic molecules.
authors.affiliation: Fraunhofer Institut für atmosphärische Umweltforschung, Garmisch-Partenkirchen, Germany.
authors.forename: A E
authors.initials: AE
authors.lastname: Wolf
authors.forename: K J
authors.initials: KJ
authors.lastname: Dietz
authors.forename: P
authors.initials: P
authors.lastname: Schröder
mesh_terms: D002268:Carboxypeptidases / Q000302:isolation & purification / Q000378:metabolism*; D002736:Chloroplasts / Q000201:enzymology; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism*; D001467:Hordeum / Q000201:enzymology*; D008658:Inactivation, Metabolic; D018515:Plant Leaves; D011523:Protoplasts / Q000201:enzymology; D013379:Substrate Specificity; D014617:Vacuoles / Q000201:enzymology*; D015262:Xenobiotics / Q000378:metabolism*
chemical_list: D015262:Xenobiotics; D002268:Carboxypeptidases; D005978:Glutathione