组蛋白翻译后修饰无标定量方法可靠性的比较

组蛋白翻译后修饰是一种表观遗传学修饰，参与调控细胞的新陈代谢等重要生理过程。蛋白质组学发展迅速，使监控组蛋白翻译后修饰的动态变化成为可能。目前主要有3种无标定量方法（谱图计数法、峰面积积分法和信号强度法），但何种定量方法更可靠尚未见系统性的详细报道。在稳定同位素标记细胞培养技术（SILAC）基础上，对去乙酰化酶抑制剂（SAHA）调控细胞乙酰化修饰水平的定量数据进行对比，比较3种无标定量方法对组蛋白翻译后修饰进行的定量分析，利用定量结果的标准差（SD）评估定量的可靠性，最终发现基于峰面积积分法定量的结果可靠性最高。该研究对难以进行同位素标记实验的样本分析，尤其对临床样本、大样本的组蛋白修饰谱分析具有重要参考意义。

Comparison of reliabilities of mass spectrometry-based label-free quantitation methods for histone post-translational modification analysis

Histone post-translational modifications (PTMs) play critical roles in epigenetic regulations of cellular physiology. The rapid development of mass spectrometry based on proteomics makes it possible to systematically widely identify and quantify the dynamic changes of histone PTMs. There are three widely used label-free quantitation methods (spectra count, peak area and intensity) for mass spectrometry data analysis, but by which method is the most reliable one for histone PTM quantification has not been systematically investigated. To this goal, we quantified histone acetylome in stable isotope amino acid labeled SH-SY5Y cells by SAHA (a pan histone deacetylase inhibitor) treatment. By comparing the standard deviations (SDs) of quantitation results from the three methods, we showed that quantification based on peak area method is the most reliable one. Therefore, our study provided new insight for label-free histone mark analysis, especially for clinical and large-scale samples.