Thioflavine-T and Congo Red Reveal the Polymorphism of Insulin Amyloid Fibrils When Probed by Polarization-Resolved Fluorescence Microscopy
Thioflavine-T and Congo Red Reveal the Polymorphism of Insulin Amyloid Fibrils When Probed by Polarization-Resolved Fluorescence Microscopy
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DOI：
10.1021/jp309528f
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发表时间：
2013-01-24
影响因子：
3.3
通讯作者：
Brasselet, Sophie
中科院分区：
文献类型：
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作者：
Duboisset, Julien;Ferrand, Patrick;Brasselet, Sophie
淀粉样原纤维是涉及β-折叠结构的蛋白质错误折叠结构，并且与各种神经退行性疾病的病理学相关。在这里，我们表明硫黄酮-T和刚果红（用于通过荧光测定对原纤维进行成像的两种主要染料）在通过偏振分辨荧光显微镜进行探测时可以提供深层结构信息。与荧光各向异性或荧光检测线性二色性成像不同，该技术允许同时检索染料的平均取向和取向分散，在此用作原纤维结构的报告者。我们已经观察到胰岛素淀粉样原纤维在原纤维的长度上表现出均匀的行为，证实了它们的结构均匀性。此外，这些结果揭示了所观察到的原纤维群体中存在各种结构，尽管当用常规荧光显微镜成像时具有类似的方面。这种光学无损技术为体内结构分析或高通量筛选开辟了前景。
Amyloid fibrils are protein misfolding structures that involve a beta-sheet structure and are associated with the pathologies of various neurodegenerative diseases. Here we show that Thioflavine-T and Congo Red, two major dyes used to image fibrils by fluorescence assays, can provide deep structural information when probed by means of polarization-resolved fluorescence microscopy. Unlike fluorescence anisotropy or fluorescence detected linear dichroism imaging, this technique allows to retrieve simultaneously both mean orientation and orientation dispersion of the dye, used here as a reporter of the fibril structure. We have observed that insulin amyloid fibrils exhibit a homogeneous behavior over the fibrils' length, confirming their structural uniformity. In addition, these results reveal the existence of various structures among the observed fibrils' population, in spite of a similar aspect when imaged with conventional fluorescence microscopy. This optical nondestructive technique opens perspectives for in vivo structural analyses or high throughput screening.