Dong Mingdong, Hovgaard Mads Bruun, Mamdouh Wael, Xu Sailong, Otzen Daniel Erik, Besenbacher Flemming
Interdisciplinary Nanoscience Center (iNANO), University of Aarhus, DK-8000 Aarhus C, Denmark. Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark.
Nanotechnology. 2008 Sep 24;19(38):384013. doi: 10.1088/0957-4484/19/38/384013. Epub 2008 Aug 12.
We report on the mechanical characterization of individual mature amyloid fibrils by atomic force microscopy (AFM) and AFM-based single-molecule force spectroscopy (SMFS). These self-assembling materials, formed from the 29-residue amphiphatic peptide hormone glucagon, were found to display a reversible elastic behaviour. Based on AFM morphology and SMFS studies, we suggest that the observed elasticity is due to a force-induced conformational transition which is reversible due to the β-helical conformation of protofibrils, allowing a high degree of extension. The elastic properties of such mature fibrils contribute to their high stability, suggesting that the internal hydrophobic interactions of amyloid fibrils are likely to be of fundamental importance in the assembly of amyloid fibrils and therefore for the understanding of the progression of their associated pathogenic disorders. In addition, such biological amyloid fibril structures with highly stable mechanical properties can potentially be used to produce nanofibres (nanowires) that may be suitable for nanotechnological applications.
我们通过原子力显微镜（AFM）和基于AFM的单分子力谱（SMFS）报告了单个成熟淀粉样纤维的力学特性。这些由29个残基的两亲性肽激素胰高血糖素形成的自组装材料表现出可逆的弹性行为。基于AFM形态学和SMFS研究，我们认为观察到的弹性是由于力诱导的构象转变，由于原纤维的β-螺旋构象，这种转变是可逆的，从而允许高度伸展。这种成熟纤维的弹性特性有助于其高稳定性，这表明淀粉样纤维的内部疏水相互作用可能在淀粉样纤维的组装中至关重要，因此对于理解其相关致病疾病的进展也很重要。此外，这种具有高度稳定力学性能的生物淀粉样纤维结构有可能用于生产可能适用于纳米技术应用的纳米纤维（纳米线）。
