Independent movement, dimerization and stability of tandem repeats of chicken brain α-spectrin
Independent movement, dimerization and stability of tandem repeats of chicken brain α-spectrin
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DOI：
10.1016/j.jmb.2004.09.019
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发表时间：
2004-11-19
影响因子：
5.6
通讯作者：
Mondragón, A
中科院分区：
文献类型：
--
作者：
Kusunoki, H;Minasov, G;Mondragón, A
先前的X射线晶体结构表明，连接鸡肉脑A-谱蛋白和人红细胞β-光谱蛋白重复的五个氨基酸残基的接头可以进行弯曲而不会失去其α-螺旋结构。为了测试一个接头的弯曲是否可以影响相邻连接器的弯曲，已经通过X射线晶体学确定了鸡脑A-光谱蛋白的两个和三个重复片段的结构。三重复片段的结构清楚地表明，一个接头的弯曲可以独立于相邻接头的弯曲。该观察结果增加了光谱重复链建模链的可能轨迹。此外，与α-肌动蛋白（一种与光谱蛋白相关的分子相比，埋入的界面面积明显小，埋入界面区域都明显小，但具有足够大的α-肌动蛋白，但指示谱的生物学特异性比较谱素和光谱素特异性比较的三个重复分子，其埋入界面面积明显小。 α-肌动蛋白二聚体支持前者的弱关联，而分析超速离心无法检测到这一点，与后者的强大关联相对，其他人观察到。为了将结构的特征与溶液特性相关联，并测试了先前的稳定光谱和肌营养不良蛋白重复的模型，对几个光谱结构的每次重复重复中的螺旋间相互作用数量进行了计数，并将其与其热稳定性进行了比较。螺旋之间的相互作用，但并非全部相互作用与每次重复的测得的热稳定性同时增加，并且与两次和三个重复的热稳定性一致，也是谱素的部分重复序列。 （c）2004 Elsevier Ltd.保留所有权利。
Previous X-ray crystal structures have shown that linkers of five amino acid residues connecting pairs of chicken brain a-spectrin and human erythroid beta-spectrin repeats can undergo bending without losing their alpha-helical structure. To test whether bending at one linker can influence bending at an adjacent linker, the structures of two and three repeat fragments of chicken brain a-spectrin have been determined by X-ray crystallography. The structure of the three-repeat fragment clearly shows that bending at one linker can occur independently of bending at an adjacent linker. This observation increases the possible trajectories of modeled chains of spectrin repeats. Furthermore, the three-repeat molecule crystallized as an antiparallel dimer with a significantly smaller buried interfacial area than that of alpha-actinin, a spectrin-related molecule, but large enough and of a type indicating biological specificity Comparison of the structures of the spectrin and alpha-actinin dimers supports weak association of the former, which could not be detected by analytical ultracentrifugation, versus strong association of the latter, which has been observed by others. To correlate features of the structure with solution properties and to test a previous model of stable spectrin and dystrophin repeats, the number of inter-helical interactions in each repeat of several spectrin structures were counted and compared to their thermal stabilities. Inter-helical interactions, but not all interactions, increased in parallel with measured thermal stabilities of each repeat and in agreement with the thermal stabilities of two and three repeats and also partial repeats of spectrin. (C) 2004 Elsevier Ltd. All rights reserved.