Characterizing post-translational modifications (PTM) of proteins is of key relevance for the understanding of many biological processes, as these covalent modifications strongly influence or even determine protein function. Among the different analytical techniques available, mass spectrometry is attracting growing attention because recent instrumental and computational improvements have led to a massive rise of the number of PTM sites that can be identified and quantified. However, multiple PTM occurring at adjacent amino acid residues can lead to complex and dense chemical patterns that are a challenge to characterize. By means of X-ray synchrotron radiation coupled to mass spectrometry, and through the test-case of the glycopeptide antibiotic vancomycin, we show that such a pattern has a unique and robust signature in terms of photon energy and molecular environment. This highlights the potential of this technique in proteomics and its value as a tool to understand the biological roles of PTM.

中文翻译：

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蛋白质中复杂翻译后修饰的质谱特征：基于 X 射线照射万古霉素的原理验证。


表征蛋白质翻译后修饰 (PTM) 对于理解许多生物过程至关重要，因为这些共价修饰强烈影响甚至决定蛋白质功能。在可用的不同分析技术中，质谱法越来越受到关注，因为最近仪器和计算的改进导致可识别和量化的 PTM 位点数量大幅增加。然而，相邻氨基酸残基上发生的多个 PTM 可能会导致复杂而密集的化学模式，这对表征来说是一个挑战。通过X射线同步辐射与质谱联用，并通过糖肽抗生素万古霉素的测试案例，我们表明这种模式在光子能量和分子环境方面具有独特而强大的特征。这凸显了该技术在蛋白质组学中的潜力及其作为了解 PTM 生物学作用的工具的价值。