Photophysical study of a π-stacked β-sheet nanofibril forming peptide bolaamphiphile hydrogel
作者:Indrajit Maity、Tushar K. Mukherjee、Apurba K. Das
DOI:10.1039/c3nj00814b
日期:——
We describe the state of molecular self-assembly of a peptide based bolaamphiphile molecule using spectroscopic and microscopic techniques. The tryptophan and phenylalanine containing peptide bolaamphiphile forms a hydrogel upon sonication under physiological conditions. Sonication helps to reorient the peptide molecules by providing the required energy for the self-assembly process. The disassembly and self-assembly processes are influenced by various stimuli, including heatingâcooling and shakingârest methods. The extensive hydrogen bonding and ÏâÏ stacking interactions are responsible for the self-assembly process, which is confirmed by FT-IR, temperature dependent NMR and fluorescence spectroscopy studies. FT-IR and powder X-ray diffraction studies reveal that the gelator molecules self-assemble into an antiparallel β-sheet type structure. The TEM image of the hydrogel shows a well-defined amyloid-like nanofibrillar structure. The amyloid-like behaviour of the fibril forming peptide bolaamphiphile hydrogel is confirmed by ThT and Congo red binding studies. The effect of concentration, time and temperature on the self-assembly mechanism of the peptide bolaamphiphile hydrogel is investigated by time resolved fluorescence spectroscopy.
我们使用光谱和显微技术描述了基于肽的双亲分子的分子自组装状态。含有色氨酸和苯丙氨酸的肽双亲性物质在生理条件下超声处理后形成水凝胶。超声处理通过提供自组装过程所需的能量来帮助重新定向肽分子。拆卸和自组装过程受到各种刺激的影响,包括加热-冷却和摇动-休息方法。广泛的氢键和α-β堆积相互作用是自组装过程的原因,这一点已通过 FT-IR、温度相关核磁共振和荧光光谱研究得到证实。 FT-IR 和粉末 X 射线衍射研究表明,胶凝剂分子自组装成反平行 β 片型结构。水凝胶的 TEM 图像显示出清晰的淀粉样蛋白样纳米纤维结构。 ThT 和刚果红结合研究证实了原纤维形成肽双亲水凝胶的淀粉样蛋白样行为。通过时间分辨荧光光谱研究了浓度、时间和温度对肽双亲水凝胶自组装机制的影响。