Separation of respective species of phytochelatins and their desglycyl peptides (class III metallothioneins) and the precursors glutathione and γ-glutamylcysteine with capillary zone electrophoresis

By exposure to excess heavy metals, plants induce phytochelatins [PCs; (gamma-Glu-Cys)(n)-Gly, n greater than or equal to 2] and their desglycyl peptides (hereafter, both are referred to as class III metallothioneins, CIIIMTs). To analyze respective CIIIMT species induced by cadmium along with glutathione (GSH) and gamma-Glu-Cys (gamma EC) that may be precursors of CIIIMT, HPCE was applied. EDTA and ABD-F (4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole, a thiol (SH)-reacting agent) were added to the supernatant fraction of root cultures of Rubia tinctorum L., and the solution was applied to HPCE apparatus [capillary zone electrophoresis, berate buffer (pH 8.5)], and the SH group was monitored at 380 nm. GSH, gamma EC, and respective CIIIMT species were separated well, and the analysis was performed within 6 min. Consequently, HPCE was found to be very useful for CIIIMT analysis. (C) 1998 Elsevier Science B.V.