A dual-functional probe that allows cascade response to hydrogen peroxide oxidative stress-induced protein aggregation in live cells

The misfolding and aggregation of specific proteins induced by endogenous oxidation are closely related to some incurable diseases including cancers, diabetes and neurodegenerative diseases. Reactive oxygen species (ROS), as a common oxidizing substance in vivo would induce the oxidation of endogenous biomacromolecules like proteins. However, it remains a challenge to detect protein aggregation induced by specific ROS. Herein, we demonstrate that the developed probe (P2) with a dual function that can simultaneously detect hydrogen peroxide (H2O2) levels and protein aggregates formed by oxidative stress. In this probe, the boronic acid pinacol ester group was conjugated to fluorescent molecular rotor 4-hydroxybenzylidene-imidazolinone (HBI) and served as the H2O2 detection group. Experimental results show that the fluorescence of P2 can be activated by H2O2 and exhibited a positive correlation with the degree of protein aggregation. Moreover, combined with AggTag method P2 was successfully applied to dual-channel imaging of protein aggregation that is stressed by H2O2 in cellular. In general, this work not only provides a potential method to study protein aggregation that associates with oxidation in live cells but also can be generally applied to study other biological processes.