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Covalent Probes for Aggregated Protein Imaging via Michael Addition
Author(s) -
Wan Wang,
Huang Yanan,
Xia Qiuxuan,
Bai Yulong,
Chen Yuwen,
Jin Wenhan,
Wang Mengdie,
Shen Di,
Lyu Haochen,
Tang Yuqi,
Dong Xuepeng,
Gao Zhenming,
Zhao Qun,
Zhang Lihua,
Liu Yu
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202015988
Subject(s) - covalent bond , chemistry , fluorescence , malachite green , chemical modification , protein aggregation , michael reaction , chemical biology , mass spectrometry , combinatorial chemistry , organic chemistry , biochemistry , chromatography , physics , adsorption , quantum mechanics , catalysis
Abstract Covalent chemical reactions to modify aggregated proteins are rare. Here, we reported covalent Michael addition can generally occur upon protein aggregation. Such reactivity was initially discovered by a bioinspired fluorescent color‐switch probe mimicking the photo‐conversion mechanism of Kaede fluorescent protein. This probe was dark with folded proteins but turned on red fluorescence (620 nm) when it non‐covalently bound to misfolded proteins. Supported by the biochemical and mass spectrometry results, the probe chemoselectively reacted with the reactive cysteines of aggregated proteins via covalent Michael addition and gradually switched to green fluorescence (515 nm) upon protein aggregation. Exploiting this Michael addition chemistry in the malachite green dye derivatives demonstrated its general applicability and chemical tunability, resulting in different fluorescence color‐switch responses. Our work may offer a new avenue to explore other chemical reactions upon protein aggregation and design covalent probes for imaging, chemical proteomics, and therapeutic purposes.