The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra, Givat Ram Campus, 91904 Jerusalem, Israel.
Phys Chem Chem Phys. 2011 Aug 14;13(30):13809-14. doi: 10.1039/c1cp20832b. Epub 2011 Jul 1.
In this paper, we characterize the dynamic nature of the full amyloid beta (1-40) (Aβ (1-40)) aggregates. We labeled the peptide with either 5-carboxytetramethylrhodamine (TAMRA) or with fluorescein-isothiocyanate (FITC). The labeled peptides were mixed after separate fibrillization, and the dynamic changes in the structure of the fibrils were imaged using confocal microscopy. Fluorescence resonance energy transfer (FRET) measurements showed that the Aβ (1-40) peptides detach from and reattach to the fibrils in a biologically relevant timescale (days). With time, the two peptides mix at the molecular level. This process is concentration dependent and occurs primarily in the external parts of the aggregates with a half time between 4 and 7 days. This study shows that the combination of confocal microscopy and FRET analysis is a facile method for studying dynamic processes in supra-molecular aggregates.
在本文中，我们描述了全长淀粉样蛋白β（1-40）（Aβ（1-40））聚集体的动态性质。我们使用 5-羧基四甲基罗丹明（TAMRA）或异硫氰酸荧光素（FITC）对肽进行标记。将标记的肽在单独的纤维化后混合，并使用共聚焦显微镜对纤维的结构动态变化进行成像。荧光共振能量转移（FRET）测量表明，Aβ（1-40）肽在生物学相关的时间尺度（数天）内从纤维上脱离并重新附着到纤维上。随着时间的推移，两种肽在分子水平上混合。该过程与浓度有关，主要发生在聚集体的外部，半衰期为 4 至 7 天。本研究表明，共聚焦显微镜和 FRET 分析的结合是研究超分子聚集体中动态过程的一种简便方法。
