Histone acetylation is an important, reversible post-translational protein modification and a hallmark of epigenetic regulation. However, little is known about the dynamics of this process, due to the lack of analytical methods that can capture site-specific acetylation and deacetylation reactions. We present a new approach that combines metabolic and chemical labeling (CoMetChem) using uniformly 13C-labeled glucose and stable isotope-labeled acetic anhydride. Thereby, chemically equivalent, fully acetylated histone species are generated, enabling accurate relative quantification of site-specific lysine acetylation dynamics in tryptic peptides using high-resolution mass spectrometry. We show that CoMetChem enables site-specific quantification of the incorporation or loss of lysine acetylation over time, allowing the determination of reaction rates for acetylation and deacetylation. Thus, the CoMetChem methodology provides a comprehensive description of site-specific acetylation dynamics.

中文翻译：

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使用稳定同位素组合代谢和化学 (CoMetChem) 标记——一种通过 LC-MS 揭示位点特异性组蛋白乙酰化和脱乙酰化率的策略

组蛋白乙酰化是一种重要的、可逆的翻译后蛋白质修饰，也是表观遗传调控的标志。然而，由于缺乏可以捕获位点特异性乙酰化和脱乙酰化反应的分析方法，对该过程的动力学知之甚少。我们提出了一种新方法，该方法使用统一的 13C 标记葡萄糖和稳定同位素标记的乙酸酐结合代谢和化学标记 (CoMetChem)。因此，产生了化学等效的、完全乙酰化的组蛋白种类，从而能够使用高分辨率质谱法对胰蛋白酶肽中的位点特异性赖氨酸乙酰化动力学进行准确的相对定量。我们表明 CoMetChem 能够对赖氨酸乙酰化的掺入或丢失随时间进行定点定量，允许确定乙酰化和脱乙酰化的反应速率。因此，CoMetChem 方法提供了位点特定乙酰化动力学的全面描述。