β-Helix is a likely core structure of yeast prion Sup35 amyloid fibers
β-Helix is a likely core structure of yeast prion Sup35 amyloid fibers
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DOI：
10.1016/j.bbrc.2004.01.117
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发表时间：
2004-03-12
影响因子：
3.1
通讯作者：
Yoshida, M
中科院分区：
文献类型：
--
作者：
Kishimoto, A;Hasegawa, K;Yoshida, M
我们研究了酵母朊蛋白Sup35淀粉样纤维的核心结构。我们开发了用三种碎片制备直径相对均匀的直纤维的方法；N (1-123), NMp (1-189)， NM（1-253）。在这三种情况下，干燥取向纤维的x射线纤维衍射图都有共同反射；在4.7埃处有一个尖锐的经向反射，在9埃左右有一个弥漫性的赤道峰，显然支持了典型的“交叉β”结构，即许多不同淀粉样蛋白纤维堆叠的β片。然而，水化纤维的x射线衍射结果显示，在这三种情况下，均有经向4.7埃反射，但在9埃没有赤道反射，这表明干燥纤维中的β片叠是干燥过程中产生的人工产物。因此，这些由N结构域构成的淀粉样纤维的核心结构很可能是Perutz等人(C) 2004 Elsevier Inc.提出的β -螺旋纳米管。版权所有。
We have studied the core structure of amyloid fibers of yeast prion protein Sup35. We developed procedures to prepare straight fibers of relatively uniform diameters from three kinds of fragments; N (1-123), NMp (1-189), and NM (1-253). X-ray fiber diffraction patterns from dried oriented fibers gave common reflections in all three cases; a sharp meridional reflection at 4.7Angstrom, and a diffuse equatorial peak at around 9Angstrom, apparently supporting the typical "cross-beta" structure with stacked beta-sheets proposed for many different amyloid fibers. However, X-ray fiber diffraction from hydrated fibers showed the meridional reflection at 4.7 Angstrom but no equatorial reflections at 9Angstrom in all three cases, indicating that the stack of beta-sheets in dried fibers is an artifact produced by drying process. Thus, the core structure of these amyloid fibers made of the N domain is likely to be beta-helix nanotube as proposed by Perutz et al. (C) 2004 Elsevier Inc. All rights reserved.