Institute of Photonic Technology, Albert-Einstein-Str. 9, 07745 Jena, Germany.
J Biophotonics. 2012 Mar;5(3):215-9. doi: 10.1002/jbio.201100142. Epub 2012 Jan 23.
Amyloid fibrils are known to be responsible for diseases such as Alzheimer's disease. A detailed insight into the structure of amyloid fibrils is fundamental since it is not yet understood what triggers the misfolding of proteins to the fiber like structures. The molecular structure of fibril surfaces on a single amino acid level has not been revealed so far but would present a valuable contribution to this question. Here we demonstrate the direct molecular distinction of selected amino acids on insulin fibril surfaces with a lateral resolution better than 2 nm by applying tip-enhanced Raman spectroscopy (TERS). This approach provides simultaneously a way to directly reveal conformational changes in the secondary structure, namely α-helix, β-sheet, on the fibril surface with nanometer resolution.
淀粉样纤维众所周知是导致阿尔茨海默病等疾病的原因。深入了解淀粉样纤维的结构是非常重要的，因为目前还不清楚是什么引发了蛋白质错误折叠成纤维样结构。到目前为止，还没有揭示出纤维表面在单个氨基酸水平上的分子结构，但这将对这个问题有很大的帮助。在这里，我们通过应用尖端增强拉曼光谱（TERS），在侧向分辨率优于 2nm 的情况下，直接对胰岛素纤维表面的选定氨基酸进行了分子区分。这种方法为直接揭示纤维表面的二级结构（即α-螺旋、β-折叠）的构象变化提供了一种方法，其分辨率可达纳米级。
