Fondazione Pisana per la Scienza ONLUS, Pisa, Italy.
Dipartimento di Chimica e Chimica Industriale, University of Pisa, Pisa, Italy.
J Am Soc Mass Spectrom. 2016 Dec;27(12):2075-2079. doi: 10.1007/s13361-016-1511-0. Epub 2016 Oct 17.
Atmospheric pressure MALDI on a Q-Exactive instrument was optimized for in-source decay and pseudo-MS. The dependence of AP-MALDI ISD on the MALDI liquid matrix was investigated for peptides and proteins. The liquid matrices enabled long-life ISD signal, and exhibited high fragment ion yield and signal stability. Extensive a-, b-, c-, y-, and z-type fragment series were observed depending on the matrix used but were most extensive with 2,5-DHB. Complete sequence coverage of small peptide and intact protein-terminus sequence tags were obtained and confirmed using HCD as a pseudo-MS method. Graphical Abstract ᅟ.
在 Q-Exactive 仪器上进行大气压基质辅助激光解吸电离（AP-MALDI）时，对源内裂解（ISD）和伪二级质谱（pseudo-MS）进行了优化。考察了肽和蛋白质的 MALDI 液体基质对 AP-MALDI ISD 的依赖性。这些液体基质可实现长寿命的 ISD 信号，并表现出高的碎片离子产率和信号稳定性。根据所使用的基质，可以观察到广泛的 a-、b-、c-、y-和 z-型碎片系列，但以 2,5-二羟基苯甲酸（2,5-DHB）最为广泛。使用高分辨碰撞解离（HCD）作为伪 MS 方法，获得了小肽和完整蛋白质末端序列标签的完整序列覆盖，并进行了确认。
