New chemistry tool spots hidden proteins linked to aging and disease
Researchers have developed a copper-based labeling system that can precisely identify and tag methionine amino acids in living cells—opening a path to better understand how proteins degrade under oxidative stress. The technique works in complex cellular environments and shows minimal toxicity, making it potentially valuable for drug development and diagnostic applications.
Originaltitel: Copper(I)-nitrene platform for chemoproteomic profiling of methionine
<p>Methionine plays a critical role in various biological and cell regulatory processes, making its chemoproteomic profiling indispensable for exploring its functions and potential in protein therapeutics. Building on the principle of rapid oxidation of methionine, we report Copper(I)-Nitrene Platform for robust, and selective labeling of methionine to generate stable sulfonyl sulfimide conjugates under physiological conditions. We demonstrate the versatility of this platform to label methionine in bioactive peptides, intact proteins (6.5-79.5 kDa), and proteins in complex cell lysate mixtures with varying payloads. We discover ligandable proteins and sites harboring hyperreactive methionine within the human proteome. Furthermore, this has been utilized to profile oxidation-sensitive methionine residues, which might increase our understanding of the protective role of methionine in diseases associated with elevated levels of reactive oxygen species. The Copper(I)-Nitrene Platform allows labeling methionine residues in live cancer cells, observing minimal cytotoxic effects and achieving dose-dependent labeling. Confocal imaging further reveals the spatial distribution of modified proteins within the cell membrane, cytoplasm, and nucleus, underscoring the platform's potential in profiling the cellular interactome. Methionine plays an essential role in various biological and cell regulatory processes, making its chemoproteomic profiling necessary to understand its function. Here, the authors present Copper(I)-Nitrene Platform (CuNiP) for robust and selective labelling of methionine to generate highly stable sulfonyl sulfimide conjugates under physiological conditions.</p>