CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, China.
University of the Chinese Academy of Sciences, Beijing 100049, China.
ACS Sens. 2022 Jul 22;7(7):1919-1925. doi: 10.1021/acssensors.2c00566. Epub 2022 Jul 1.
Deterioration of protein homeostasis (proteostasis) often induces aberrant proteome aggregation. Visualization and dissection of the stressed proteome are of particular interest given their association with numerous degenerative diseases. Recent progress in chemical cellular stress sensors allows for direct visualization of aggregated proteome. Beyond its localization and morphology, the physicochemical nature and the dynamics of the aggregated proteome have been challenging to explore. Herein, we developed a series of solvatochromic fluorene-based D-πA probes that can selectively and noncovalently bind to a misfolded and aggregated proteome and report on their compactness heterogeneity upon cellular stresses. We achieved this goal by variation of the heterocyclic acceptors to modulate their solvatochromism and binding affinity to amorphous aggregated proteins. The optimized sensor P6 was capable of sensing the polarity differences among different aggregated proteins via its fluorescence emission wavelength. In live cells, P6 revealed the cellular compactness heterogeneity in the aggregated proteome upon cellular stresses. Given the combinative solvatochromic and noncovalent properties, our probe can reversibly monitor the dynamic changes in the aggregated proteome compactness upon stress and after stress recovery, suggesting its potential applications in search of therapeutics to counteract disease-causing proteome stresses.
蛋白质动态平衡（蛋白质稳态）的恶化通常会导致异常的蛋白质组聚集。鉴于它们与许多退行性疾病有关，因此对受应激的蛋白质组进行可视化和剖析具有特别的意义。化学细胞应激传感器的最新进展使得能够直接可视化聚集的蛋白质组。除了定位和形态之外，聚集蛋白质组的物理化学性质和动力学一直难以探索。在此，我们开发了一系列基于芴的溶剂化变色 D-πA 探针，它们可以选择性地非共价结合到错误折叠和聚集的蛋白质组上，并报告细胞应激时其紧凑性的异质性。我们通过改变杂环受体来实现这一目标，以调节它们的溶剂变色和对无定形聚集蛋白的结合亲和力。优化后的传感器 P6 能够通过其荧光发射波长来感知不同聚集蛋白之间的极性差异。在活细胞中，P6 揭示了细胞应激时聚集蛋白质组中细胞紧凑性的异质性。鉴于组合的溶剂变色和非共价性质，我们的探针可以在应激和应激恢复后可逆地监测聚集蛋白质组紧凑性的动态变化，这表明其在寻找治疗方法以对抗引起疾病的蛋白质组应激方面具有潜在的应用。
