The formation of spherulites by amyloid fibrils of bovine insulin
The formation of spherulites by amyloid fibrils of bovine insulin
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DOI：
10.1073/pnas.0405933101
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发表时间：
2004-10-05
影响因子：
11.1
通讯作者：
Donald, AM
中科院分区：
文献类型：
--
作者：
Krebs, MRH;MacPhee, CE;Donald, AM
牛胰岛素在体外自组装成淀粉样原纤维是众所周知的。我们已经观察到了进一步的高阶自关联的蛋白质成球形结构，直径通常约为50 μ m，但范围从10到150 μ m。在偏光显微镜下，这些结构表现出典型的球晶的“马耳他十字”消光图案。在环境扫描电子显微镜中可以观察到类似尺寸分布的球形结构，这也揭示了结构中存在大量的水。球晶含有大量的明确定义的淀粉样蛋白原纤维，这表明它们至少部分地是由于预形成的原纤维的自组装而形成的。在患有淀粉样蛋白疾病的患者的组织中也观察到类似的结构。淀粉样蛋白原纤维形成这种高阶组装体的能力支持了这样的假设，即它们代表了具有与经典合成聚合物类似的性质的多肽结构的一般形式。
Bovine insulin has long been known to self-assemble in vitro into amyloid fibrils. We have observed a further higher-order self-association of the protein into spherical structures, with diameters typically around 50 mum but ranging from 10 to 150 mum. In a polarizing light microscope, these structures exhibit a "Maltese-cross" extinction pattern typical of spherulites. Spherical structures of a similar size distribution can be observed in the environmental scanning electron microscope, which also reveals the presence of significant amounts of water in the structures. The spherulites contain a large quantity of well defined amyloid fibrils, suggesting that they are formed at least in part as a consequence of the self-assembly of preformed fibrils. Similar structures also have been observed in the tissues of patients suffering from amyloid disorders. The ability of amyloid fibrils to form such higher-order assemblies supports the hypothesis that they represent a generic form of polypeptide structure with properties that are analogous to those of classical synthetic polymers.