The use of advanced glycation end-products (AGEs) as biomarkers for diagnosis and clinical studies is still hampered by insufficient knowledge on clinically relevant structures formed from precursors associated with defined disease states. The present study conducted untargeted analysis of the glycating activity of AGE-precursors by ultrahigh performance liquid chromatography/tandem mass spectrometry multiple reaction monitoring (UHPLC/MSMS-MRM), monitoring the loss of a nonapeptide as the glycation target. Thus, the glycating activities of seven important AGE-precursors were determined (glucose 13% and the reactive carbonyl compounds glucosone 39%, 3-deoxyglucosone 15%, 3-deoxygalactosone 26%, 3,4-dideoxyglucosone-3-ene 79%, methylglyoxal 94%, and glyoxal 97% peptide loss; 12 h/37 °C). Furthermore, UHPLC/MSMS with simultaneous precursor ion scan and information-dependent acquisition of enhanced resolution spectra and subsequent product ion scan was applied for untargeted analysis of the major AGE-structures derived from various AGE-precursors. The 20 most important modifications could be assigned to 8 AGE-structures previously reported in the literature. Seven loosely bound AGEs not yet covered by conventional methods were detected and assigned to hemiaminals. Five AGE structures did not match any known products. The method can be applied to analyze glycating activity and AGE-structures formed from various other precursors under defined reaction conditions, supporting the selection and evaluation of diagnostic AGE-markers for clinical studies.
使用高级糖基化终产物(AGEs)作为诊断和临床研究的
生物标志物仍受到对与特定疾病状态相关的前体形成的临床相关结构了解不足的限制。本研究通过超高效
液相色谱/串联质谱多反应监测(UHPLC/MSMS-MRM)进行非靶向分析,监测非肽的损失作为糖基化靶标,从而评估AGE前体的糖基化活性。因此,确定了七种重要AGE前体的糖基化活性(
葡萄糖13%和反应性羰基化合物
葡萄糖酮39%、3-去氧
葡萄糖酮15%、3-去氧半
乳糖酮26%、3,4-去氧
葡萄糖酮-3-烯79%、
甲基乙二醛94%和
乙醛97%肽损失;12小时/37°C)。此外,使用UHPLC/MSMS的同时前体离子扫描和信息依赖获取的增强分辨率光谱及后续产物离子扫描对来自不同AGE前体的主要AGE结构进行非靶向分析。20个最重要的修饰可归属于文献中先前报道的8种AGE结构。检测到7种传统方法尚未覆盖的松散结合AGE,并将其归属于半
氨基醇。五种AGE结构与任何已知产品不匹配。该方法可用于分析在特定反应条件下由各种其他前体形成的糖基化活性和AGE结构,支持临床研究中诊断AGE标志物的选择和评估。