Fluorescent Probe DCVJ Shows High Sensitivity for Characterization of Amyloid β-Peptide Early in the Lag Phase.
Fluorescent Probe DCVJ Shows High Sensitivity for Characterization of Amyloid β-Peptide Early in the Lag Phase.
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荧光探针 DCVJ 对滞后期早期淀粉样蛋白 β 肽的表征显示出高灵敏度。
DOI：
10.1002/cbic.201700387
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Lapidus,LisaJ
中科院分区：
文献类型：
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作者：
Nagarajan,Sureshbabu;Lapidus,LisaJ
本质上无序和错误折叠的蛋白质以低聚物和原纤维形式聚集在许多神经系统和神经退行性疾病中发挥着至关重要的作用。目前，大多数以高分辨率检测和表征原纤维的探针和生物物理技术未能显示出对低聚物的灵敏度和结合。在这里，我们发现9-（二氰基乙烯基）久洛利定（DCVJ），一类分子转子，结合淀粉样β（Aβ）早期聚集体，我们报告的动力学以及低聚物形成的包装。DCVJ与Aβ40的结合使其在510 nm处的发射强度随时间增加，并在575 nm处产生第二个准分子峰。 但DCVJ不与Aβ42的前纤维聚集体结合，表明Aβ40和Aβ42形成的寡聚体不同。Aβ40的F4 C F19 W突变体（不形成原纤维）也与DCVJ结合，但发射光谱特征与野生型（WT）不同。WT Aβ40、F4 C F19 W突变体和Aβ42寡聚体的原子力显微镜图像显示出大小和形状的差异，证实了其DCVJ光谱的差异。还观察到表没食子儿茶素-3-没食子酸酯（EGCG）对Aβ42纤维减少的影响，其细节比其他技术更精细。本研究的结果表明，DCVJ检测早期聚集体，并提供有关低聚物动力学，包装和形成机制的有价值的信息。
The aggregation of intrinsically disordered and misfolded proteins in the form of oligomers and fibrils plays a crucial role in a number of neurological and neurodegenerative diseases. Currently, most probes and biophysical techniques that detect and characterize fibrils at high resolution fail to show sensitivity and binding for oligomers. Here, we show that 9‐(dicyano‐vinyl)julolidine (DCVJ), a class of molecular rotor, binds amyloid beta (Aβ) early aggregates, and we report the kinetics as well as packing of the oligomer formation. The binding of DCVJ to Aβ40 increased its emission intensity with time at 510 nm and produced a second excimer peak at 575 nm. However, DCVJ did not bind to the prefibrillar aggregates of Aβ42, which indicated that the oligomers formed by Aβ40 and Aβ42 were not the same. The F4C F19W mutant of Aβ40, which did not form fibrils, also bound DCVJ, but the emission spectral profile varied from that of the wild‐type (WT). Atomic force microscopy images of WT Aβ40, the F4C F19W mutant, and Aβ42 oligomers displayed differences in size and shape, confirming the difference in their DCVJ spectra. The effect of epigallocatechin‐3‐gallate (EGCG) on the reduction of Aβ42 fibrils was also observed with finer detail than with other techniques. The results of this study show that DCVJ detects early aggregates and provides valuable information regarding the oligomer kinetics, packing, and mechanism of formation.