Schulz E, Karas M, Rosu F, Gabelica V
Institute of Pharmaceutical Chemistry, Johann-Wolfgang Goethe University Frankfurt, Frankfurt am Main, Germany.
Department of Chemistry, Mass Spectrometry Laboratory, University of Liège, Institut de Chimie, Bat. B6c, B-4000, Liège, Belgium.
J Am Soc Mass Spectrom. 2006 Jul;17(7):1005-1013. doi: 10.1016/j.jasms.2006.03.009. Epub 2006 May 19.
In this paper, we report the measurement of the degree of analyte fragmentation in AP-MALDI as a function of the matrix and of the laser fluence. The analytes include p-OCH3-benzylpyridinium, three peptides containing the sequence EEPP (which cleave very efficiently at the E-P site), and three deoxynucleosides (dA, dG, and dC), which lose the neutral sugar to give the protonated base. We found that the matrix hardness/softness was consistent when comparing the analytes, with a consensus ranking from hardest to softest: CHCA >> DHB > SA approximately THAP > ATT > HPA. However, the exact ranking can be fluence-dependent, for example between ATT and HPA. Our goal here was to provide the scientific community with a detailed dataset that can be used to compare with theoretical predictions. We tried to correlate the consensus ranking with different matrix properties: sublimation or decomposition temperature (determined using thermogravimetry), analyte initial velocity, and matrix proton affinity. The best correlation was found with the matrix proton affinity.
在本文中，我们报告了在常压基质辅助激光解吸电离（AP-MALDI）中，分析物碎片化程度随基质和激光能量密度的变化情况。分析物包括对甲氧基苄基吡啶鎓、三种含有EEPP序列的肽（在E-P位点高效裂解）以及三种脱氧核苷（dA、dG和dC），它们失去中性糖得到质子化碱基。我们发现，在比较分析物时，基质的硬度/软度是一致的，从最硬到最软的共识排序为：α-氰基-4-羟基肉桂酸（CHCA）>> 2,5-二羟基苯甲酸（DHB）> 芥子酸（SA）≈ 噻吩甲酰三氟丙酮（THAP）> 2-氨基-5-噻唑啉酮（ATT）> 3-羟基吡啶甲酸（HPA）。然而，确切的排序可能取决于能量密度，例如在ATT和HPA之间。我们的目标是为科学界提供一个详细的数据集，可用于与理论预测进行比较。我们试图将共识排序与不同的基质性质相关联：升华或分解温度（使用热重分析法测定）、分析物初始速度和基质质子亲和力。发现与基质质子亲和力的相关性最佳。
