Temporini Caterina, Calleri Enrica, Massolini Gabriella, Caccialanza Gabriele
Department of Pharmaceutical Chemistry, University of Pavia, Via Taramelli 12, 27100 Pavia, Italy.
Mass Spectrom Rev. 2008 May-Jun;27(3):207-36. doi: 10.1002/mas.20164.
The post-translational modification (PTM) of proteins is a common biological mechanism for regulating protein localization, function, and turnover. The direct analysis of modifications is required because they are not coded by genes, and thus are not predictable. Different MS-based proteomic strategies are used for the analysis of PTMs, such as phosphorylation and glycosylation, and are composed of a structural simplification step of the protein followed by specific isolation step to extract the classes of modified peptides (also called "sub-proteomes") before mass spectrometry. This specific isolation step is necessary because PTMs occur at a sub-stoichiometric level and signal suppression of the modified fractions in the mass spectrometer occurs in the presence of the more-abundant non-modified counterpart. The request of innovative analytical strategies in PTM studies is the capability to localize the modification sites, give detailed structural information on the modification, and determine the isoform composition with increased selectivity, sensitivity, and throughput. This review focuses on the description of recent integrated analytical systems proposed for the analysis of PTMs in proteins, and their application to profile the glycoproteome and the phosphoproteome in biological samples. Comments on the difficulties and usefulness of the analytical strategies are given.
蛋白质的翻译后修饰（PTM）是调节蛋白质定位、功能和周转的常见生物学机制。由于修饰并非由基因编码，因此无法预测，所以需要对其进行直接分析。不同的基于质谱的蛋白质组学策略用于分析PTM，如磷酸化和糖基化，这些策略包括蛋白质的结构简化步骤，随后是特定的分离步骤，以在质谱分析之前提取修饰肽类（也称为“亚蛋白质组”）。这一特定的分离步骤是必要的，因为PTM以亚化学计量水平发生，并且在质谱仪中，修饰部分的信号会在存在更丰富的未修饰对应物时受到抑制。PTM研究中对创新分析策略的要求是能够定位修饰位点、提供修饰的详细结构信息，并以更高的选择性、灵敏度和通量确定异构体组成。本综述重点描述了最近提出的用于分析蛋白质中PTM的集成分析系统，以及它们在分析生物样品中糖蛋白质组和磷酸蛋白质组方面的应用。同时对分析策略的难点和实用性进行了评论
