• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Molecular Biology >SOLUTION STRUCTURE OF (CD2+)(1)-CALBINDIN D-9K REVEALS DETAILS OF THE STEPWISE STRUCTURAL CHANGES ALONG THE APO-](CA2+)(1)(II)-](CA2+)(2)(I,II) BINDING PATHWAY
【24h】

SOLUTION STRUCTURE OF (CD2+)(1)-CALBINDIN D-9K REVEALS DETAILS OF THE STEPWISE STRUCTURAL CHANGES ALONG THE APO-](CA2+)(1)(II)-](CA2+)(2)(I,II) BINDING PATHWAY

机译：（CD2 +）（1）-CALBINDIN D-9K揭示APO-] [CA2 +] [1] [II]-] [CA2 +] [2] [I，II）结合途径逐步结构变化的详细信息

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The three-dimensional solution structure of (Cd2+)(1)-calbindin D-9k has been determined by distance geometry, restrained molecular dynamics and relaxation matrix calculations using experimental constraints obtained from two-dimensional H-1 and N-15-H-1 NMR spectroscopy The final input data consisted of 1055 NOE distance constraints and 71 dihedral angle constraints, corresponding to 15 constraints per residue on average. The resulting ensemble of 24 structures has no distance or dihedral angle constraints consistently violated by more than 0.07 Angstrom and 1.8 degrees, respectively. The structure is characteristic of an EF-hand protein, with two helix-loop-helix calcium binding motifs joined by a flexible linker, and a short anti-parallel beta-type interaction between the two ion-binding sites. The four helices are well defined with a root mean square deviation from the mean coordinates of 0.35 Angstrom for the backbone atoms. The structure of the half-saturated cadmium state was compared with the previously determined solution structures of the apo and fully calcium saturated calbindin D-9k. The comparisons were aided by introducing the ensemble averaged distance difference matrix as a tool for analyzing differences between two ensembles of structures. Detailed analyses of differences between the three states in backbone and side-chain dihedral angles, hydrogen bonds, interatomic distances, and packing of the hydroyhobic core reveal the reorganization of the protein that occurs upon ion binding. Overall, it was found that (Cd2+)(1)-calbindin D-9k, representing the half-saturated calcium state with an ion in site II, is structurally more similar to the fully calcium-saturated state than the apo state. Thus, for the binding sequence apo --> (Ca2+)(1)(II) --> (Ca2+)(2)(I,II), the structural changes occurring upon ion binding are most pronounced for the first binding step, an observation that bears significantly on the molecular basis for cooperative calcium binding in calbindin D-9k. [References: 80]
机译：（Cd2 +）（1）-calbindin D-9k的三维溶液结构已通过使用二维H-1和N-15-H-获得的实验约束条件通过距离几何，受限分子动力学和弛豫矩阵计算确定1 NMR谱图最终输入数据包括1055个NOE距离约束和71个二面角约束，平均每个残基15个约束。所得的24个结构的合奏没有距离或二面角约束始终分别超过0.07埃和1.8度。该结构是EF手蛋白的特征，具有两个通过柔性接头连接的螺旋-环-螺旋钙结合基序，并且两个离子结合位点之间具有短的反平行β型相互作用。四个螺旋的定义很好，均方根均方根与骨架原子的平均坐标为0.35埃。将半饱和镉态的结构与先前确定的载脂蛋白和完全钙饱和钙结合蛋白D-9k的溶液结构进行了比较。通过引入集合平均距离差矩阵作为分析两个结构之间的差异的工具来辅助比较。详细分析骨架和侧链二面角，氢键，原子间距离和疏水性核心堆积这三个状态之间的差异，揭示了离子结合后发生的蛋白质重组。总体而言，发现（Cd2 +）（1）-钙结合蛋白D-9k代表半饱和的钙状态，且在位点II处有离子，其结构上比全载脂蛋白状态更类似于完全钙饱和的状态。因此，对于结合序列apo->（Ca2 +）（1）（II）->（Ca2 +）（2）（I，II），在离子结合时发生的结构变化在第一个结合步骤中最为明显，这一观察结果在分子基础上对钙结合蛋白D-9k中的协同钙结合具有重要意义。 [参考：80]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号