title: SEC ICP MS and CZE ICP MS investigation of medium and high molecular weight complexes formed by cadmium ions with phytochelatins.
abstract: Size-exclusion chromatography (SEC) and capillary zone electrophoresis (CZE) coupled with inductively coupled plasma mass spectrometry were applied to characterize low, medium, and high molecular weight cadmium complexes with glutathione and phytochelatins (PCs). The dominant stoichiometry of the complexes formed in vitro was established as 1:1 using electrospray ionization mass spectrometry. Calculated molecular masses of Cd1L1 complexes were used for calibration of the SEC and CZE methods. The results showed a lower (2 kDa) SEC column exclusion limit for cadmium complexes compared with free peptides (10 kDa), and most of the high molecular weight cadmium species were eluted in the void volume of the column. Moreover, the CZE method based on the semiempirical model of Offord to elucidate peptide migration allowed us to show a high propensity of Cd-PC complexes for polymorphism on complexation, which was also observed for extracts of Arabidopsis thaliana treated with cadmium. All the information presented is vital for understanding the mechanism of metal deactivation in plants.
authors.affiliation: Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Miszczak
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rosłon
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Zbroja
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Brama
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Szalacha
authors.forename: Helena
authors.initials: H
authors.lastname: Gawrońska
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Pawlak
mesh_terms: D017360:Arabidopsis / Q000737:chemistry*; D002104:Cadmium / Q000032:analysis* / Q000737:chemistry; D002850:Chromatography, Gel / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D007477:Ions / Q000032:analysis / Q000737:chemistry; D008970:Molecular Weight; D054811:Phytochelatins / Q000737:chemistry*; D010936:Plant Extracts / Q000032:analysis* / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D007477:Ions; D010936:Plant Extracts; D002104:Cadmium; D054811:Phytochelatins