Glycosylation is one of the most common protein modifications, and it is essential for mammalian cell survival. It often determines protein folding and trafficking, and regulates nearly every extracellular activity, including cell–cell communication and cell–matrix interactions. Aberrant protein glycosylation events are hallmarks of human diseases such as cancer and infectious diseases. Therefore, glycoproteins can serve as effective biomarkers for disease detection and targets for drug and vaccine development. Despite the importance of glycoproteins, global analysis of protein glycosylation (either glycoproteins or glycans) in complex biological samples has been a daunting task, and here we mainly focus on glycoprotein analysis using mass spectrometry (MS)-based bottom-up proteomics. Although the emergence of MS-based proteomics has provided a great opportunity to analyze glycoproteins globally, the low abundance of many glycoproteins and the heterogeneity of glycans dramatically increase the technical difficulties. In order to overcome these obstacles, considerable progress has been made in recent years, which has contributed to comprehensive analysis of glycoproteins. In our lab, we developed effective MS-based chemical and enzymatic methods to (1) globally analyze glycoproteins in complex biological samples, (2) target glycoproteins specifically on the surface of human cells, (3) systematically quantify glycoprotein and surface glycoprotein dynamics (the abundance changes of glycoproteins as a function of time), and (4) selectively characterize glycoproteins with a particular and important glycan.

中文翻译：

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基于质谱的化学和酶促方法对蛋白质糖基化进行整体​​分析

糖基化是最常见的蛋白质修饰之一，对于哺乳动物细胞的生存至关重要。它通常决定蛋白质的折叠和运输，并调节几乎所有的细胞外活性，包括细胞与细胞之间的通讯以及细胞与基质的相互作用。异常的蛋白质糖基化事件是人类疾病（例如癌症和传染病）的标志。因此，糖蛋白可以作为疾病检测的有效生物标志物以及药物和疫苗开发的靶标。尽管糖蛋白很重要，但复杂生物样品中蛋白质糖基化（糖蛋白或聚糖）的全局分析一直是一项艰巨的任务，在这里，我们主要关注使用基于质谱（MS）的自下而上的蛋白质组学进行糖蛋白分析。尽管基于MS的蛋白质组学的出现为在全球范围内分析糖蛋白提供了巨大的机会，但是许多糖蛋白的丰度低和聚糖的异质性极大地增加了技术难度。为了克服这些障碍，近年来已经取得了相当大的进步，这为糖蛋白的综合分析做出了贡献。在我们的实验室中，我们开发了有效的基于MS的化学和酶促方法，以（1）全面分析复杂生物样品中的糖蛋白;（2）专门针对人细胞表面的靶糖蛋白;（3）系统地定量糖蛋白和表面糖蛋白动力学（ （糖蛋白的丰度变化随时间的变化），以及（4）选择性地表征具有特定和重要聚糖的糖蛋白。