Direct observation of Aβ amyloid fibril growth and inhibition
Direct observation of Aβ amyloid fibril growth and inhibition
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DOI：
10.1016/j.jmb.2004.09.078
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发表时间：
2004-11-26
影响因子：
5.6
通讯作者：
Goto, Y
中科院分区：
文献类型：
--
作者：
Ban, T;Hoshino, M;Goto, Y
淀粉样原纤维形成是许多蛋白质和肽的常见现象，包括与阿尔茨海默病相关的淀粉样β（Abeta）肽。为了阐明原纤维形成的机制并产生抑制剂，必须实时监测原纤维的生长。在这里，使用全内反射荧光显微镜（TIRFM）结合硫磺素T（淀粉样蛋白特异性荧光染料）的结合，在单个原纤维水平上实时观察Abeta（1-40）的种子依赖性淀粉样蛋白原纤维生长。原纤维的清晰图像和显著长度使得能够精确分析单个原纤维的生长速率，表明原纤维生长是以恒定速率延伸原纤维末端的高度协作过程。已经知道A淀粉样蛋白的形成是立体特异性反应，并且其稳定性受L/D-氨基酸取代的影响。针对这些方面，我们设计了几种Abeta（25-35）类似物，Abeta（1-40）的细胞毒性片段，由L和D-氨基酸残基组成，并通过TIRFM检查其抑制作用。一些嵌合Abeta（25-35）肽。强烈抑制Abeta（25-35）的纤维生长，但它们不能抑制Abeta（1-40）的生长。结果表明，立体特异性抑制剂的更合理的设计，结合纤维生长的实时监测，将有助于发明一种有效的抑制剂，防止A β（1-40）和其他蛋白质的淀粉样纤维生长。(C)2004爱思唯尔有限公司保留所有权利。
Amyloid fibril formation is a phenomenon common to many proteins and peptides, including amyloid beta (Abeta) peptide associated with Alzheimer's disease. To clarify the mechanism of fibril formation and to create inhibitors, real-time monitoring of fibril growth is essential. Here, seed-dependent amyloid fibril growth of Abeta(1-40) was visualized in real-time at the single fibril level using total internal reflection fluorescence microscopy (TIRFM) combined with the binding of thioflavin T, an amyloid-specific fluorescence dye. The clear image and remarkable length of the fibrils enabled an exact analysis of the rate of growth of individual fibrils, indicating that the fibril growth was a highly cooperative process extending the fibril ends at a constant rate. It has been known that A amyloid formation is a stereospecific reaction and the stability is affected by L/D-amino acid replacement. Focusing on these aspects, we designed several analogues of Abeta(25-35), a cytotoxic fragment of Abeta(1-40), consisting of L and D-amino acid residues, and examined their inhibitory effects by TIRFM. Some chimeric Abeta(25-35) peptides. inhibited the fibril growth of Abeta(25-35) strongly, although they could not inhibit the growth of Abeta(1-40). The results suggest that a more rational design of stereospecific inhibitors, combined with real-time monitoring of fibril growth, will be useful to invent a potent inhibitor preventing the amyloid fibril growth of Abeta(1-40) and other proteins. (C) 2004 Elsevier Ltd. All rights reserved.