蚯蚓钙调素二级结构的研究及Ca^(2+),Tb^(3+)的影响  

FT IR Study on the Secondary Structure of Earthworm Calmodulin(CaM) and the Effects of Ca 2+ and Tb 3+ Ions

作　　者：王立波[1] 吴瑾光[1] 徐光宪[1] 王采芹[2] 张庭芳[2] 

机构地区：[1]北京大学化学与分子工程学院 [2]北京大学生命科学学院

出　　处：《北京大学学报（自然科学版）》1997年第6期699-707,共9页Acta Scientiarum Naturalium Universitatis Pekinensis

基　　金：国家自然科学基金;国家教委博士点基金

摘　　要：运用ＦＴ－ＩＲ方法的分辨率增强及曲线拟合技术对水化膜中蚯蚓钙调素ＣａＭ的二级结构以及加入不同比例Ｃａ２＋、Ｔｂ３＋后ＣａＭ二级结构的变化进行了研究。结果表明，水化膜中ＣａＭ及含不同比例Ｃａ２＋或Ｔｂ３＋的蛋白复合物的α－ｈｅｌｉｘ的含量较晶体和溶液中为低，而β－ｓｈｅｅｔ和ｔｕｒｎ结构的含量相对较高。研究发现不同比例金属离子的加入，引起了ＣａＭ二级结构不同程度的变化，但各类结构在总量上观察不到明显的变化规律，且由于结合机制的不同，Ｃａ２＋和Ｔｂ３＋的影响也各不相同。Ｔｂ３＋可与ＣａＭ中的Ｃａ结合位点结合，在一定条件下激活ＣａＭ，但在较高浓度下，Ｔｂ３＋的结合抑制ＣａＭ的活性。The Secondary structure of earthworm Calmodulin(CaM) in thin film was measured by using FT IR spectroscopic method and curve fitting technique, and the effects of Ca 2+ and Tb 3+ were investigated in detail. The results show that CaM exhibits lower content of α helix and relatively higher contents of β sheet and β turn structure in film than that in crystal or water solution. To some extent, the addition of different ratios of Ca 2+ and Tb 3+ induced different conformation changes, which indicates that the two ions have different combination mechanisms. Moreover, the activity to stimulate the PDE enzyme and the SDS PAGE behavior of CaM with different metal ions were also studied. The results show that Tb 3+ can active CaM under low concentration, but inhibit the activity of CaM under high concentration, which suggests that Tb 3+ have different physiology role from Ca 2+ .

关 键 词：FTIR 二级结构 蚯蚓 钙调素 钙离子 铽离子 

分 类 号：Q959.193[生物学—动物学] Q513