Skelton N J, Kördel J, Akke M, Forsén S, Chazin W J
Department of Molecular Biology, Scripps Research Institute, La Jolla, California 92037, USA.
Nat Struct Biol. 1994 Apr;1(4):239-45. doi: 10.1038/nsb0494-239.
The three-dimensional structure of calbindin D9k in the absence of Ca2+ has been determined using NMR spectroscopy in solution, allowing the first direct analysis of the consequences of Ca2+ binding for a member of the calmodulin superfamily of proteins. The overall response in calbindin D9k is much attenuated relative to the current model for calmodulin and troponin C. These results demonstrate a novel mechanism for modulating the conformational response to Ca(2+)-binding in calmodulin superfamily proteins and provide insights into how their Ca(2+)-binding domains can be fine-tuned to remain essentially intact or respond strongly to ion binding, in relation to their functional requirements.
利用溶液中的核磁共振光谱法已确定了无Ca2+时钙结合蛋白D9k的三维结构，从而首次直接分析了Ca2+结合对钙调蛋白超家族蛋白质成员的影响。相对于目前关于钙调蛋白和肌钙蛋白C的模型，钙结合蛋白D9k的整体反应要弱得多。这些结果证明了一种调节钙调蛋白超家族蛋白质对Ca(2+)结合的构象反应的新机制，并就如何根据其功能需求对其Ca(2+)结合结构域进行微调以使其基本保持完整或对离子结合产生强烈反应提供了见解。
