Synthetic and Functional Biomolecules Center, Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China.
ACS Chem Biol. 2022 Aug 19;17(8):2010-2017. doi: 10.1021/acschembio.2c00017. Epub 2022 Jul 7.
Methylglyoxal (MGO) is a highly reactive metabolite mainly formed as a byproduct of glycolysis. Elevated MGO has been considered as a risk factor for several diseases including diabetes and neurodegeneration. While MGO modifications on proteins were globally profiled, the cross-links between proteins induced by MGO in proteomes are unexplored to date. Here, we reported a quantitative chemoproteomic platform based on mass shifts that enables identification of events of protein cross-links induced by MGO in proteomes. A total of 66 cross-linked targets were identified from the profiling experiments when cells were treated with MGO, among which the components of functional complexes such as spliceosomes and ribosomes were enriched. We found that inosine-5'-monophosphate dehydrogenase 2 (IMPDH2) was homocross-linked by MGO and the active-site Cys331 was critical for mediating the cross-link, which in turn affected IMPDH2's activity. Our study has provided new clues for the functional impact in proteomes by MGO, and the methodology can be, in principle, applied to profile protein cross-links induced by other reactive metabolites.
甲基乙二醛（MGO）是一种高度反应性的代谢物，主要作为糖酵解的副产物形成。MGO 水平升高被认为是包括糖尿病和神经退行性变在内的几种疾病的危险因素。虽然 MGO 对蛋白质的修饰已被全面研究，但迄今为止，MGO 在蛋白质组中诱导的蛋白质交联还没有被探索过。在这里，我们报道了一种基于质量位移的定量化学蛋白质组学平台，该平台可用于鉴定 MGO 在蛋白质组中诱导的蛋白质交联事件。当细胞用 MGO 处理时，从分析实验中鉴定出了 66 个交联靶标，其中包括剪接体和核糖体等功能复合物的成分。我们发现 MGO 使肌苷 5'-单磷酸脱氢酶 2（IMPDH2）发生同源交联，活性位点半胱氨酸 331 对于介导交联至关重要，进而影响 IMPDH2 的活性。我们的研究为 MGO 对蛋白质组功能的影响提供了新的线索，并且该方法原则上可以应用于分析其他反应性代谢物诱导的蛋白质交联。
