title: gamma-Glutamylcysteinylglutamic acid--a new homologue of glutathione in maize seedlings exposed to cadmium.
abstract: Exposure of plants to Cd induces the appearance of several thiols based on glutathione and known as class III metallothioneins (or phytochelatins). A new tripeptide with the structure gamma-GluCysGlu accumulated in roots and shoots of Cd-exposed maize seedlings. This thiol was purified and identified by tandem mass spectrometry. The fragmentation pattern of the maize tripeptide was identical to that of the synthetic compound. Like glutathione, this new tripeptide may serve as a precursor for longer-chain peptides involved in metal detoxification through the formation of Cd-binding complexes.
authors.affiliation: Department of Botany, College of Biological Sciences, University of Guelph, Ont, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Meuwly
authors.forename: P
authors.initials: P
authors.lastname: Thibault
authors.forename: W E
authors.initials: WE
authors.lastname: Rauser
mesh_terms: D000595:Amino Acid Sequence; D002104:Cadmium / Q000633:toxicity*; D019187:Cadmium Compounds; D002851:Chromatography, High Pressure Liquid; D005978:Glutathione / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism; D007700:Kinetics; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000032:analysis / Q000378:metabolism*; D013431:Sulfates; D013997:Time Factors; D003313:Zea mays / Q000187:drug effects* / Q000378:metabolism
chemical_list: D019187:Cadmium Compounds; D009842:Oligopeptides; D013431:Sulfates; D002104:Cadmium; C085214:gamma-glutamyl-cysteinyl-glutamic acid; C037123:cadmium sulfate; D005978:Glutathione