Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark.
Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen N, Denmark.
Methods Mol Biol. 2022;2499:261-273. doi: 10.1007/978-1-0716-2317-6_13.
Post-translational modifications (PTMs) of proteins play crucial roles in defining protein function. They often do not occur alone, leading to a large variety of proteoforms that correspond to different combinations of multiple PTMs simultaneously decorating a protein. Changes of these proteoforms can be quantified via middle-down and top-down mass spectrometry experiments where the simultaneous PTM settings are obtained by measuring long peptides or entire proteins. Data from such experiments poses big challenges in identifying relevant features of biological and clinical importance. Generally, multiple data layers need to be considered such as proteoforms, individual PTMs, and PTM types. Therein, visualization methods are a crucial part of data analysis as they provide, if applied correctly, insights into both general behaviors as well as a deep view into fine-grained behavior. Here, we present a workflow to visualize histone proteins and their myriad of PTMs based on different R visualization modules applied to data from quantitative middle-down experiments. The procedure can be adapted to diverse experimental designs and is applicable to different proteins and PTMs.
蛋白质的翻译后修饰(PTMs)在定义蛋白质功能方面起着至关重要的作用。它们通常不是单独发生的,导致了大量的蛋白异构体,这些异构体对应于多种 PTM 同时修饰蛋白质的不同组合。可以通过中肽和从头质谱实验来定量这些蛋白异构体的变化,其中通过测量长肽或整个蛋白质来获得同时存在的 PTM 设置。来自这些实验的数据在识别具有生物学和临床重要性的相关特征方面带来了巨大的挑战。通常,需要考虑多个数据层,如蛋白异构体、单个 PTM 和 PTM 类型。在这方面,可视化方法是数据分析的关键部分,因为它们如果正确应用,不仅可以提供对一般行为的深入了解,还可以深入了解细粒度的行为。在这里,我们提出了一种基于应用于定量中肽实验数据的不同 R 可视化模块来可视化组蛋白及其众多 PTM 的工作流程。该过程可以适应不同的实验设计,适用于不同的蛋白质和 PTM。