Analytical Biochemistry and Mass Spectrometry Core Facility, Department of Pharmacy, University of Groningen, A. Deusinglaan 1, 9713 AV Groningen, The Netherlands.
Anal Bioanal Chem. 2010 Aug;397(8):3441-55. doi: 10.1007/s00216-010-3471-8. Epub 2010 Feb 13.
Oxidation of proteins and peptides is a common phenomenon, and can be employed as a labeling technique for mass-spectrometry-based proteomics. Nonspecific oxidative labeling methods can modify almost any amino acid residue in a protein or only surface-exposed regions. Specific agents may label reactive functional groups in amino acids, primarily cysteine, methionine, tyrosine, and tryptophan. Nonspecific radical intermediates (reactive oxygen, nitrogen, or halogen species) can be produced by chemical, photochemical, electrochemical, or enzymatic methods. More targeted oxidation can be achieved by chemical reagents but also by direct electrochemical oxidation, which opens the way to instrumental labeling methods. Oxidative labeling of amino acids in the context of liquid chromatography(LC)-mass spectrometry (MS) based proteomics allows for differential LC separation, improved MS ionization, and label-specific fragmentation and detection. Oxidation of proteins can create new reactive groups which are useful for secondary, more conventional derivatization reactions with, e.g., fluorescent labels. This review summarizes reactions of oxidizing agents with peptides and proteins, the corresponding methodologies and instrumentation, and the major, innovative applications of oxidative protein labeling described in selected literature from the last decade.
蛋白质和肽的氧化是一种常见的现象，可作为基于质谱的蛋白质组学的标记技术。非特异性氧化标记方法可以修饰蛋白质中的几乎任何氨基酸残基，或者仅修饰表面暴露的区域。特异性试剂可以标记氨基酸中的反应性功能基团，主要是半胱氨酸、蛋氨酸、酪氨酸和色氨酸。非特异性自由基中间体（活性氧、氮或卤素物种）可以通过化学、光化学、电化学或酶方法产生。更有针对性的氧化可以通过化学试剂实现，但也可以通过直接电化学氧化来实现，这为仪器标记方法开辟了道路。在基于液相色谱（LC）-质谱（MS）的蛋白质组学中，对氨基酸进行氧化标记可以实现差异 LC 分离、改善 MS 离子化以及针对标签的片段化和检测。蛋白质的氧化可以产生新的反应性基团，这些基团可用于与例如荧光标记物的二次、更常规的衍生化反应。本文综述了氧化剂与肽和蛋白质的反应、相应的方法和仪器以及过去十年中选定文献中描述的氧化蛋白质标记的主要创新应用。
