STRUCTURAL CHARACTERIZATION OF A PARTLY FOLDED APOMYOGLOBIN INTERMEDIATE
STRUCTURAL CHARACTERIZATION OF A PARTLY FOLDED APOMYOGLOBIN INTERMEDIATE
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DOI：
10.1126/science.2218495
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发表时间：
1990-09-28
期刊：
影响因子：
56.9
通讯作者：
BALDWIN, RL
中科院分区：
文献类型：
--
作者：
HUGHSON, FM;WRIGHT, PE;BALDWIN, RL
为了理解为什么蛋白质采用特定的三维结构，重要的是要阐明稳定天然状态的相互作用层次。部分折叠状态的蛋白质可以用来剖析蛋白质的组织层次。部分折叠的脱辅基肌红蛋白中间体现在已经通过捕获缓慢交换的肽NH质子并通过二维1H-NMR（核磁共振）分析它们来表征结构。A、G和H螺旋区域中的质子被保护而不被交换，而B和E螺旋区域中的质子自由交换。基于这些结果和天然肌红蛋白的三维结构，提出了一个结构模型的部分折叠的中间体，其中一个紧凑的子域保留结构，而其余的蛋白质基本上是展开的。
To understand why proteins adopt particular three-dimensional structures, it is important to elucidate the hierarchy of interactions that stabilie the native state. Proteins in partly folded states can be used to dissect protein organization hierarchies. A partly folded apomyoglobin intermediate has now been characterized structurally by trapping slowly exchanging peptide NH protons and analyzing them by two-dimensional 1H-NMR (nuclear magnetic resonance). Protons in the A, G, and H helix regions are protected from exchange, while protons in the B and E helix regions exchange freely. On the basis of these results and the three-dimensional structure of native myoglobin, a structural model is presented for the partly folded intermediate in which a compact subdomain retains structure while the remainder of the protein is essentially unfolded.