Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes...Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes for other membranes.The putative plasma membrane fraction was minimally contaminated by membranes Other than plasma membrane and hence was of high purity. It exhibited a Ca2+dependent ATPase activity, which was inhibited by 1μ mol/L EB and promoted by calcium ionophore A23187. Such an activity was responsible for the observed ATPdependent 45Ca2+ uptake into inside-out plasma membrane vesicles. This process was stimulated by 0.6μmol/L CaM and 20μmol/L IAA but inhibited by 2μmol/L ABA and abolished by A23187. Possible role of cytoplasmic Ca2+ in mediating phytohormones activity is discussed.展开更多
文摘Plasma membrane vesicles were prepared from the developing cotyledons of common beau (Phaseolus vulgaris L cv Diyundou) by aqueous two-phase partitioning and characterized as to their purity by assaying marker enzymes for other membranes.The putative plasma membrane fraction was minimally contaminated by membranes Other than plasma membrane and hence was of high purity. It exhibited a Ca2+dependent ATPase activity, which was inhibited by 1μ mol/L EB and promoted by calcium ionophore A23187. Such an activity was responsible for the observed ATPdependent 45Ca2+ uptake into inside-out plasma membrane vesicles. This process was stimulated by 0.6μmol/L CaM and 20μmol/L IAA but inhibited by 2μmol/L ABA and abolished by A23187. Possible role of cytoplasmic Ca2+ in mediating phytohormones activity is discussed.
