【摘要】 分离纯化旱生植物柠条的叶细胞质膜，测定其Ca2＋-ATPase的最适反应pH、最适反应温度、底物ATP和激活剂Ca2＋对酶活性的影响，并与中生植物小麦叶细胞质膜Ca2＋-ATPase的性质进行比较。实验表明柠条叶细胞质膜Ca2＋-ATPase的最适反应pH为7．5，最适反应温度为55℃，酶对ATP的Hill系数为0．94，符合米氏动力学类型，对Ca2＋的Hill系数为0．35，具有负协同作用。还测定了柠条和小麦叶片中及叶细胞质膜结合的钙调素含量，发现钙调素含量与植物的抗旱性成正相关。更多还原

【Abstract】 Plasma membrane was separated from xerophyte korshinsk peashrub leaves. Optimum reaction pH and optimum reaction temperature of plasma membrane Ca2+-ATPase, effects of substrate ATP and activator Ca2+ on the enzyme activity were determined. Optimum reaction pH was 7. 5. The optimum reaction temperature was 55℃. Hill coefficient of the enzyme for ATP was 0. 94,being in keeping,with Michaelis-Menten dynamics. For Ca2+ activation,Hill coefficient of the enzyme was 0. 35, which suggest a negative cooperativity. The results were compared with those from mesophyte wheat leaf plasma membrane Ca2+-ATPase. The contents of calmodulin in leaf and binding with leaf plasma membrane were determined from korshinsk peashrub and wheat. The positive correlation between Calmodulin contents and drought resistance of plants was obtained.更多还原