Warwick Centre for Analytical Science, Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK.
Rapid Commun Mass Spectrom. 2014 Jan 15;28(1):25-32. doi: 10.1002/rcm.6753.
The post-translational modification known as glycation affects the physiological properties of peptides and proteins. Glycation is particularly important during hyperglycaemia where α-dicarbonyl compounds are generated. These compounds react with proteins to generate α-dicarbonyl-derived glycation products, which are correlated with diabetic complications such as nephropathy, retinopathy, and neuropathy, among others. One of these α-dicarbonyl compounds is ethanedial, also known as glyoxal. Thereby, glyoxal binding to protein/peptides is studied by electron capture dissociation (ECD) and collisionally activated dissociation (CAD).
Acetylated and non-acetylated undecapeptides containing one lysine and one arginine susceptible of glycation were reacted with glyoxal under pseudo-physiological and MeOH/H2O (50:50) conditions. Two types of glyoxal-derived AGEs were fragmented by ECD and CAD using 12 Tesla Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS).
Reaction with glyoxal under different reaction conditions showed the addition of C2O and C2H2O2, which corresponded to a net increase on the peptide mass of 39.9949 Da and 58.0055 Da, respectively. The binding site was assigned within an error <1 ppm, using ECD and CAD. The results indicated that both types of glyoxal-derived AGEs are formed at the side chain of arginine located in position 3.
Types and binding sites of glyoxal-derived AGEs were investigated in peptides containing one arginine-one lysine using FTICRMS. Two net mass additions to the mass of the peptide were assigned as C2O and C2H2O2, which were located at the arginine side chain. In addition, these mass additions (C2O and C2H2O2) observed in the peptides were unaffected by different reaction conditions.
被称为糖基化的翻译后修饰会影响肽和蛋白质的生理特性。在高血糖期间，α-二羰基化合物生成，糖基化尤其重要。这些化合物与蛋白质反应生成α-二羰基衍生的糖基化产物，与糖尿病并发症如肾病、视网膜病变和神经病等有关。这些α-二羰基化合物之一是乙二醛，也称为乙醛酸。因此，通过电子俘获解离（ECD）和碰撞激活解离（CAD）研究乙醛酸与蛋白质/肽的结合。
在拟生理条件和 MeOH/H2O（50:50）条件下，使含有一个赖氨酸和一个易发生糖基化的精氨酸的乙酰化和非乙酰化十一肽与乙醛酸反应。使用 12 特斯拉傅里叶变换离子回旋共振质谱（FTICRMS）通过 ECD 和 CAD 使两种类型的乙醛酸衍生 AGE 断裂。
在不同反应条件下与乙醛酸反应显示了 C2O 和 C2H2O2 的加成，分别对应于肽质量的净增加 39.9949 Da 和 58.0055 Da。使用 ECD 和 CAD，在 <1 ppm 的误差范围内分配了结合位点。结果表明，两种类型的乙醛酸衍生 AGE 都在位于 3 位的精氨酸侧链上形成。
使用 FTICRMS 在含有一个精氨酸-一个赖氨酸的肽中研究了乙醛酸衍生 AGE 的类型和结合位点。分配给肽质量的两个净质量增加被指定为 C2O 和 C2H2O2，它们位于精氨酸侧链上。此外，在肽中观察到的这些质量增加（C2O 和 C2H2O2）不受不同反应条件的影响。
