Abstract
Xenobiotics, (e.g. agrochemicals), exposed to higher plants are conjugated to glutathione by the glutathione-S-transferase. Finally, conjugated xenobiotics might be transported into the vacuole by GS-X pump(GS-XP), and seguestnated. In this study we attempt to isolate the GS-X pump gene and to detect some changes in physical properties of biomembrane depend on the GS-XP activities. We synthesized S-(2,4-dinitrophenyl) glutathione (DNP-GS), as a model compound of the xenobiotic to plant, and the fluidities of vacuolar membranes were measured to investigate the effect of this compound on the permeability to vacuolar membranes. However, any remarkable fluidity change among different conditions for GS-XP activities in tonoplast vesicles has not measured until now. Then use of membrane from transgenic yeast overexpressing the GS-XP is planned. As the gene used for this, two fragments of the GS-XP gene were isolated. GS-X transport activity was measured by [3H]DNP-GS uptake and ATP dependency of GS-XP was comfirmed.
