Actin bundles cross-linked with -actinin studied by nanobeam X-ray diffraction

作者：Toepperwien M; Priebe M; Salditt T^*

来源：European Biophysics Journal, 2016, 45(5): 383-392.

DOI：10.1007/s00249-015-1107-9

• Actin bundles
• alpha-Actinin
• X-ray diffraction

We have performed scanning nano-beam small-angle X-ray scattering (nano-SAXS) experiments on in vitro-formed actin filaments cross-linked with -actinin. The experimental method combines a high resolution in reciprocal space with a real space resolution as given by the spot-size of the nano-focused X-ray beam, and opens up new opportunities to study local super-molecular structures of actin filaments. In this first proof-of-concept, we show that the local orientation of actin bundles formed by the cross-linking can be visualized by the X-ray darkfield maps. The filament bundles give rise to highly anisotropic diffraction patterns showing distinct streaks perpendicular to the bundle axes. Interestingly, some diffraction patterns exhibit a fine structure in the form of intensity modulations allowing for a more detailed analysis of the order within the bundles. A first empirical quantification of these modulations is included in the present work.

• 出版日期2016-7