Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, Krakow 30-387, Poland.
Doctoral School of Exact and Natural Sciences, Jagiellonian University, Lojasiewicza 11, Krakow 30-348, Poland.
Chem Commun (Camb). 2023 Sep 7;59(72):10793-10796. doi: 10.1039/d3cc03216g.
Amyloid fibrils form remarkable, multi-layered chiral supramolecular architectures. The proximity of interacting oscillators in the chiral fibril supramolecules is responsible for the unusual sensitivity of vibrational circular dichroism (VCD) for fibril formation. Surprisingly, up to now, such characteristics have not been shown for ROA, although it displays the same vibrational markers of fibrils as VCD, including the amide I band. Here, we report an exceptionally large enhancement of the ROA signal detected for mature amyloid fibrils and their prefibrillar states. Remarkably, the same ROA signal has been obtained for fibrils of homologous lysozymes and the dissimilar protein, insulin, indicating a possible common enhanced ROA spectrum, analogous to that for VCD for all amyloid fibrils investigated to date. The ROA signal is observed at earlier stages of fibril formation than VCD and provides access to a considerably broader range of vibrations. Further studies are necessary to verify the applicability of ROA for the analysis of amyloid fibrils.
淀粉样纤维形成显著的、多层次的手性超分子结构。手性纤维超分子中相互作用的振荡器的接近程度是振动圆二色性（VCD）对手性纤维形成的不寻常敏感性的原因。令人惊讶的是，到目前为止，ROA 还没有表现出这种特性，尽管它显示了与 VCD 相同的纤维振动标记，包括酰胺 I 带。在这里，我们报告了成熟的淀粉样纤维及其原纤维状态的 ROA 信号的异常大增强。值得注意的是，同种溶菌酶和不同蛋白质胰岛素的纤维也得到了相同的 ROA 信号，表明可能存在一种共同的增强的 ROA 光谱，类似于迄今为止所有研究过的淀粉样纤维的 VCD。ROA 信号在纤维形成的早期阶段就被观察到，并且可以访问更广泛的振动范围。需要进一步的研究来验证 ROA 在手性纤维分析中的适用性。
