Analysis of phytochelatin-cadmium complexes from plant tissue culture using nano-electrospray ionization tandem mass spectrometry and capillary liquid chromatography/electrospray ionization tandem mass spectrometry

✍ Scribed by Yen, Ten-Yang; Villa, Joseph A.; DeWitt, Jane G.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 182 KB
• Volume: 34
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199909)34:9<930::aid-jms853>3.0.co;2-e

✦ Synopsis

Phytochelatins (PCs, also known as class III metallothioneins), a family of sulfhydryl-rich peptides with the formula (g-GluCys) n Gly(Pc n , n = 2-11), are induced in plants, yeast and fungi exposed to heavy metals, and are thought to detoxify metals by forming PC-metal complexes. Although PCs have been detected, PC-metal complexes have not been well characterized. In this work, nano-electrospray ionization tandem mass spectrometry (nano-ESI-MS/MS) and capillary liquid chromatography/electrospray ionization tandem mass spectrometry (capillary LC/ESI-MS/MS) methods were used to analyze PC-Cd complexes isolated from Datura innoxia, also known as Jimsonweed, cell culture exposed to Cd. With nano-ESI-MS/MS and capillary LC/ESI-MS/MS we could simultaneously detect the presence of PCs and PC-Cd complexes from plant cell extracts, unambiguously identify these species and elucidate the nature of individual PC-Cd complexes. Phytochelatins with n = 3-6 were detected, as were PC-Cd complexes with PC 3 , PC 4 and PC 5 . This is the first study to report the size and nature of native PC-Cd complexes from plant tissue samples. These results demonstrate that the direct analysis of plant extracts using nano-ESI-MS/MS and capillary LC/ESI-MS/MS methods is simple and sensitive to the range of PCs and PC-Cd complexes in plants. Hence these methods open up new opportunities for further quantitative analysis of PCs and PC-metal complexes in cell culture and plant systems to understand the relationship between the biosynthesis of these compounds and metal tolerance.