Finamore Francesco, Priego-Capote Feliciano, Nolli Severine, Zufferey Anne, Fontana Pierre, Sanchez Jean-Charles
Translational Biomarker Group (TBG), Department of Human Protein Sciences, University Medical Centre, University of Geneva, 1211 Geneva 4, Switzerland.
Department of Analytical Chemistry, Annex C-3 Building, Campus of Rabanales, University of Còrdoba, Spain.
J Proteomics. 2015 Jan 30;114:125-35. doi: 10.1016/j.jprot.2014.11.005. Epub 2014 Nov 20.
The competition effect between aspirin-mediated acetylation and protein glycation has been a matter of concern for decades. However, the exact interactions between these two post-translational modifications are still not well understood. Several efforts have been made to explain how aspirin prevents glycation, but the influence of prior protein glycation on the action of aspirin has never been investigated. This study involved qualitative and quantitative analyses to: 1) identify acetylated and glycated proteins; 2) quantify rates of acetylation and glycation; and 3) elucidate the common modification sites. Human plasma was incubated with 30mM glucose and then 500μM aspirin. A label-free mass spectrometry approach indicated an increase in the acetylation level after this sequential glucose-then-aspirin incubation; these results were also confirmed by Western blot. Interestingly, for several proteins, decreases in glycation levels were evidenced after aspirin incubation. The common modification sites, where both acetylation and glycation took place, were also identified. The influence that glycation and acetylation processes have on each other could reflect conformational changes induced by glucose and aspirin. In future studies, in order to better understand the interactions between these two PTMs, we intend to apply this strategy to other blood compartments and to diabetic patients.
Non-enzymatic glycation represents an early stage in the development of the long-lasting complications that are associated with diabetes. Aspirin has been shown to prevent this process in a few reference proteins, but how the two post-translational modifications (PTMs) of aspirin-mediated acetylation and protein glycation interact with each other remains poorly investigated. This study used a label-free quantitative proteomic approach to characterise the extent of aspirin-induced acetylation and protein glycation in human plasma. The results clearly supported a mutual influence between these PTMs, which lead us to propose a potential model based on structural conformational changes.
几十年来，阿司匹林介导的乙酰化与蛋白质糖基化之间的竞争效应一直备受关注。然而，这两种翻译后修饰之间的确切相互作用仍未得到充分理解。人们已经做出了一些努力来解释阿司匹林如何预防糖基化，但先前蛋白质糖基化对阿司匹林作用的影响从未被研究过。本研究涉及定性和定量分析，以：1）鉴定乙酰化和糖基化蛋白质；2）量化乙酰化和糖基化速率；3）阐明常见的修饰位点。将人血浆与30mM葡萄糖孵育，然后加入500μM阿司匹林。一种无标记质谱方法表明，在依次进行葡萄糖-然后-阿司匹林孵育后，乙酰化水平有所增加；这些结果也通过蛋白质印迹法得到了证实。有趣的是，对于几种蛋白质，在阿司匹林孵育后糖基化水平有所降低。还鉴定了同时发生乙酰化和糖基化的常见修饰位点。糖基化和乙酰化过程相互之间的影响可能反映了由葡萄糖和阿司匹林诱导的构象变化。在未来的研究中，为了更好地理解这两种翻译后修饰之间的相互作用，我们打算将这种策略应用于其他血液成分和糖尿病患者。
非酶糖基化是与糖尿病相关的长期并发症发展的早期阶段。阿司匹林已被证明在一些参考蛋白质中可预防这一过程，但阿司匹林介导的乙酰化和蛋白质糖基化这两种翻译后修饰如何相互作用仍研究不足。本研究使用无标记定量蛋白质组学方法来表征人血浆中阿司匹林诱导的乙酰化和蛋白质糖基化程度。结果清楚地支持了这些翻译后修饰之间的相互影响，这使我们基于结构构象变化提出了一个潜在模型。
