Department of Chemistry, Emory University, Atlanta, GA, USA.
Department of Pathology and Laboratory Medicine, Emory University, Atlanta, GA, USA.
Nat Commun. 2024 May 18;15(1):4243. doi: 10.1038/s41467-024-48403-0.
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.
甲硫氨酸在各种生物和细胞调节过程中起着关键作用，因此对其进行化学蛋白质组学分析对于探索其在蛋白质治疗中的功能和潜力是必不可少的。基于甲硫氨酸快速氧化的原理，我们报告了铜（I）-氮烯平台，该平台可在生理条件下对甲硫氨酸进行稳健、选择性标记，生成稳定的磺酰亚磺酰亚胺缀合物。我们证明了该平台在生物活性肽、完整蛋白质（6.5-79.5 kDa）以及含有不同负载的复杂细胞裂解物混合物中的甲硫氨酸标记的多功能性。我们在人类蛋白质组中发现了含有超反应性甲硫氨酸的可配体蛋白和位点。此外，这已被用于分析氧化敏感的甲硫氨酸残基，这可能增加我们对甲硫氨酸在与活性氧水平升高相关的疾病中保护作用的理解。铜（I）-氮烯平台允许在活癌细胞中标记甲硫氨酸残基，观察到最小的细胞毒性作用，并实现了剂量依赖性标记。共焦成像进一步揭示了修饰蛋白在细胞膜、细胞质和核内的空间分布，突出了该平台在细胞相互作用组分析中的潜力。
