Wang Wenpin, Guo Zongxia, Sun Jing, Li Zhibo
School of Polymer Science and Engineering, Qingdao University of Science and Technology, Qingdao, 266042, China.
Biopolymers. 2017 Feb;107(2):61-69. doi: 10.1002/bip.22992.
The comprehensive understanding of disassembly mechanism of amyloid fibrils requires nano-scale characterization of the mechanical properties of amyloid fibrils during the disassembly process. In this work, gemini surfactant C C C Br micelles were used as a probe to disassemble Aβ(1-40) fibrils. The microstructure evolution and nano-mechanical properties of Aβ(1-40) fibrils during the disassembly process were systematically investigated by the Peak Force Quantitative Nano-mechanical (PF-QNM) technique. The results show an obvious decrease in Young's modulus of mature fibrils with high β-sheet contents (2.4 ± 1.0 GPa) in comparison to the resulting peptide/surfactant complexes (1.1 ± 0.8 GPa) with loose surface structures. Interestingly, the Young's modulus of spherical peptide/surfactant complexes on the core was more than 3 GPa. This strategy can be used as a standard protocol to investigate the interaction mechanism between amyloid fibrils and small molecules, which may open up new possibilities to explore the mechanism of relevant human diseases.
对淀粉样蛋白原纤维拆解机制的全面理解需要在拆解过程中对淀粉样蛋白原纤维的力学性能进行纳米级表征。在这项工作中，双子表面活性剂C C C Br胶束被用作拆解Aβ(1-40)原纤维的探针。通过峰值力定量纳米力学（PF-QNM）技术系统地研究了Aβ(1-40)原纤维在拆解过程中的微观结构演变和纳米力学性能。结果表明，与表面结构松散的肽/表面活性剂复合物（1.1±0.8 GPa）相比，具有高β-折叠含量的成熟原纤维（2.4±1.0 GPa）的杨氏模量明显降低。有趣的是，核心上球形肽/表面活性剂复合物的杨氏模量超过3 GPa。该策略可作为研究淀粉样蛋白原纤维与小分子之间相互作用机制的标准方案，这可能为探索相关人类疾病的机制开辟新的可能性。
