轻稀土离子对钙调蛋白激活的磷酸二酯酶活力作用的影响  

THE EFFECTS LIGHT RARE EARTH IONS (Ln￣(3+))ON THE ACTIVITY OF PHOSPHODIESTERASE STIMULATED BY CALMODULIN

作　　者：陈旭[1] 周玉祥[1] 徐育敏[1] 

机构地区：[1]清华大学生物科学与技术系生物膜与膜生物工程国家重点实验室

出　　处：《生物物理学报》1996年第3期389-393,共5页Acta Biophysica Sinica

基　　金：国家自然科学基金

摘　　要：研究了轻稀土离子（Ｌｎ３＋）对钙调蛋白（ＣａＭ）调控的磷酸二酯酶（ＰＤＥ）活力的影响。结果表明，在无Ｃａ２＋的ＣａＭ（Ａｐｏ—ＣａＭ）体系中，由ＣａＭ调节的ＰＤＥ的活力随Ｌｎ３＋浓度的变化曲线是双相效应，即在高浓度时，Ｌｎ３＋具有抑制ＣａＭ调节ＰＤＥ活力的能力；低浓度的Ｌｎ３＋可以提高ＣａＭ调节ＰＤＥ活力的能力。在Ｃａ２＋４－ＣａＭ－ＰＤＥ体系中，高浓度的Ｌｎ３＋的加入能抑制ＣｈＭ调节ＰＤＥ活力的能力，其抑制程度因其离子不同而异。ＣａＭ的两类拮抗剂ＪｕＡ（非竞争性抑制剂）和ＴＦＰ（竞争性抑制剂）都能抑制ＣａＭ－Ｌｎ３＋－ＰＤＥ系统的活性。最后对Ｌｎ３＋和ＣａＭ相互作用的分子机制进行了初步的讨论。The effects of light rare earth ions (Ln3+) on the activity of phosphodiesterase (PDE) stimulated by calmodulin (CaM) have been studied. The results revealed that the curve of PDE activeity stimulated by CaM(in absence Ch2+) in different Ln3+ concentration is aparently biphase.Ln3+ can activate CaM almost as same as Ca2+ at low concentration, but they have strongly inhibitive function at high concentration. In addition, Ln3+ at high concentration can inhibit the activity of PDE stimulated by CaM (in presence of Ca2+) and the inhibition effect is dependent on the different ions. Two types of inhibition: trifluopenazine (TEP, a competitive inhibitor of CaM) and jujubosideA (JuA, a non-competitive inhibitor of CaM) can inhibit the activity of PDE stimulated by Ln-CaM. The mechanism of molecular interaction between Ln3+ and CaM has been discussed.

关 键 词：磷酸二酯酶 稀土离子 钙调蛋白 

分 类 号：Q556.102[生物学—生物化学] Q61