Femtosecond X-ray coherent diffraction of aligned amyloid fibrils on low background graphene
Femtosecond X-ray coherent diffraction of aligned amyloid fibrils on low background graphene
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DOI：
10.1038/s41467-018-04116-9
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发表时间：
2018-05-09
影响因子：
16.6
通讯作者：
Chapman，Henry N.
中科院分区：
文献类型：
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作者：
Seuring，Carolin;Ayyer，Kartik;Chapman，Henry N.
在这里，我们提出了一种新的方法来衍射成像的淀粉样纤维，结合独立的石墨烯支持和单纳米聚焦X射线脉冲的飞秒持续时间从X射线自由电子激光。由于来自石墨烯支撑物的非常低的背景散射和细丝的相互对准，在单个衍射图案中分别获得了烟草花叶病毒（TMV）细丝和淀粉样蛋白原纤维的2.7 μ m和2.4 μ m分辨率的衍射。一些TMV衍射图案表现出不对称性，这表明在XFEL焦点中存在有限数量的轴向旋转。使用计算对齐和合并，从个别衍射图案的信号噪声水平得到增强，给出上级从同步辐射源获得的图案。我们预计，我们的方法将是一个起点，进一步调查未解决的结构的细丝和其他弱散射物体。
Here we present a new approach to diffraction imaging of amyloid fibrils, combining a free-standing graphene support and single nanofocused X-ray pulses of femtosecond duration from an X-ray free-electron laser. Due to the very low background scattering from the graphene support and mutual alignment of filaments, diffraction from tobacco mosaic virus (TMV) filaments and amyloid protofibrils is obtained to 2.7 Å and 2.4 Å resolution in single diffraction patterns, respectively. Some TMV diffraction patterns exhibit asymmetry that indicates the presence of a limited number of axial rotations in the XFEL focus. Signal-to-noise levels from individual diffraction patterns are enhanced using computational alignment and merging, giving patterns that are superior to those obtainable from synchrotron radiation sources. We anticipate that our approach will be a starting point for further investigations into unsolved structures of filaments and other weakly scattering objects.