Department of Chemistry, School of Science, Westlake University, Hangzhou, 310030, Zhejiang Province, China.
Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, 310024, Zhejiang Province, China.
Angew Chem Int Ed Engl. 2024 Oct 7;63(41):e202408564. doi: 10.1002/anie.202408564. Epub 2024 Sep 10.
Proteomics is a powerful method to comprehensively understand cellular posttranslational modifications (PTMs). Owing to low abundance, tryptic peptides with PTMs are usually enriched for enhanced coverage by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). Affinity chromatography for phosphoproteomes by metal-oxide and pan-specific antibodies for lysine acetylome allow identification of tens of thousands of modification sites. Lysine methylation is a significant PTM; however, only hundreds of methylation sites were identified by available approaches. Herein we report an aryl diazonium based chemoselective strategy that enables enrichment of monomethyllysine (Kme1) peptides through covalent bonds with extraordinary sensitivity. We identified more than 10000 Kme1 peptides from diverse cell lines and mouse tissues, which implied a wide lysine methylation impact on cellular processes. Furthermore, we found a significant amount of methyl marks that were not S-adenosyl methionine (SAM)-dependent by isotope labeling experiments.
蛋白质组学是一种全面了解细胞翻译后修饰（PTMs）的强大方法。由于丰度低，带有 PTM 的胰蛋白酶肽通常通过液相色谱-质谱/质谱（LC-MS/MS）进行富集以提高覆盖率。金属氧化物亲和色谱法用于磷酸蛋白质组学，泛特异性抗体用于赖氨酸乙酰化组学，可鉴定数万种修饰位点。赖氨酸甲基化是一种重要的 PTM；然而，现有的方法只能鉴定数百个甲基化位点。在此，我们报告了一种基于芳基重氮的化学选择性策略，该策略通过共价键以极高的灵敏度富集单甲基赖氨酸（Kme1）肽。我们从多种细胞系和小鼠组织中鉴定出超过 10000 个 Kme1 肽，这表明赖氨酸甲基化对细胞过程有广泛的影响。此外，通过同位素标记实验，我们发现了大量非 S-腺苷甲硫氨酸（SAM）依赖性的甲基标记。
