Intramolecular Proton and Charge Transfer of Pyrene-based trans-Stilbene Salicylic Acids Applied to Detection of Aggregated Proteins.
Intramolecular Proton and Charge Transfer of Pyrene-based trans-Stilbene Salicylic Acids Applied to Detection of Aggregated Proteins.
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基于芘的反式二苯乙烯水杨酸的分子内质子和电荷转移应用于聚集蛋白的检测。
DOI：
10.1002/cphc.201800823
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Lindgren,Mikael
中科院分区：
文献类型：
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作者：
Zhang,Jun;Wang,Jun;Sandberg,Alexander;Wu,Xiongyu;Nyström,Sofie;LeVine3rd,Harry;Konradsson,Peter;Hammarström,Per;Durbeej,Bo;Lindgren,Mikael
以反式二苯乙烯芘为骨架，合成了2个淀粉样蛋白荧光探针2，5-二（4′-羟基-3 ′-羧基-苯乙烯基）苯（X-34）的类似物（Py 1 SA和Py 2SA）。当与预先形成的Aβ1-42纤维结合时，化合物显示出明显不同的发射光谱。当与四种不同蛋白质的淀粉样纤维结合时，这种显着的发射差异被保留，这表明每个分子具有共同的结合构型。密度泛函理论计算表明，Py 1 SA是扭曲的，而Py 2SA是更平面。尽管如此，最高占据分子轨道（HOMO）和最低未占分子轨道（LUMO）的两种化合物的分析表明，芘和水杨酸（SA）部分之间的电子耦合的程度是在Py 1 SA大于Py 2SA。在极性溶剂中观察到阴离子形式的激发态分子内质子转移（ESIPT）耦合电荷转移（ICT）。我们的结论是，ICT性能oftrans-stilbene衍生物可用于淀粉样蛋白探针的设计与大的变化，从类似的化学结构的发射光谱和衰减时间取决于详细的物理性质的结合位点。
Two analogues to the fluorescent amyloid probe 2,5‐bis(4′‐hydroxy‐3′‐carboxy‐styryl)benzene (X‐34) were synthesized based on thetrans‐stilbene pyrene scaffold (Py1SA and Py2SA). The compounds show strikingly different emission spectra when bound to preformed Aβ1–42 fibrils. This remarkable emission difference is retained when bound to amyloid fibrils of four distinct proteins, suggesting a common binding configuration for each molecule. Density functional theory calculations show that Py1SA is twisted, while Py2SA is more planar. Still, an analysis of the highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) of the two compounds indicates that the degree of electronic coupling between the pyrene and salicylic acid (SA) moieties is larger in Py1SA than in Py2SA. Excited state intramolecular proton transfer (ESIPT) coupled‐charge transfer (ICT) was observed for the anionic form in polar solvents. We conclude that ICT properties oftrans‐stilbene derivatives can be utilized for amyloid probe design with large changes in emission spectra and decay times from analogous chemical structures depending on the detailed physical nature of the binding site.