钙调磷酸酶B亚基钙结合位点的突变对B亚基结构和功能的影响  

Structure and function of calcineurin B subunit:mutation in the calcium binding site

作　　者：尹燕霞[1] 佟丽[1] 黄建华 姜国华 YIN Yanxia;TONG Li;HUANG Jianhua;JIANG Guohua(College of Life Sciences,Beijing Key Laboratory of Genetic Engineering Drugs and Biotechnology,Beijing Normal University,100875,Beijing,China;Analysis and Testing Center,Beijing Normal University,100875,Beijing,China)

机构地区：[1]北京师范大学生命科学学院,北京市基因工程药物及生物技术重点实验室,北京100875 [2]北京师范大学分析测试中心,北京100875

出　　处：《北京师范大学学报（自然科学版）》2021年第2期205-212,共8页Journal of Beijing Normal University(Natural Science)

基　　金：国家自然科学基金资助项目(30770478)。

摘　　要：应用远紫外CD光谱、紫外差光谱、内源荧光光谱以及ANS荧光光谱,探究了钙调磷酸酶B亚基钙结合位点的突变对B亚基结构和功能的影响.结果显示:钙结合位点突变体Y105W激活CNA的能力强于CNB;而E110Q活化CNA的能力弱于CNB;Y105W和E110Q与Ca2+亲和性低于CNB;CNB和它的突变体二级结构趋于一致,但三级结构存在明显差异,这种差异可能是它们功能差异的结构基础.Effect of mutations in the calcium binding site on calcineurin B subunit structure and function was investigated,by far ultraviolet CD spectrum,ultraviolet difference spectrum,endogenous fluorescence spectrum and ANS fluorescence spectrum. It was found that calcium binding site mutant CNB-Y105 W was stronger than wild type CNB to activate CNA,but CNB-E110 Q was weaker. The affinity of CNB-Y105 W and CNB-E110 Q for Ca2+ was both found to be lower than CNB. The secondary structures were found to be similar among CNB and the 2 mutants,but their tertiary structures showed significant differences,consistent with their differences in protein activity.

关 键 词：钙调磷酸酶 CA2+ 磷酸酶活性 三级结构 钙结合位点 

分 类 号：Q556[生物学—生物化学]