Preliminary ESI-MS and MALDI-TOF Analysis on Phosphorylated Tetrapeptides with Xaa-Pro Motif.

Autor: Zhen-Tai Zhu, Yan-Mei Li, Yan-Ting Guo, Ming Sun, Yu-Fen Zhao
Předmět:
Zdroj: Phosphorus, Sulfur & Silicon & the Related Elements; Apr2007, Vol. 182 Issue 4, p825-834, 10p, 5 Diagrams, 1 Chart, 2 Graphs
Abstrakt: To investigate the side-chain effects of O-phosphorylation on the peptidyl-prolyl amide bond cis/trans isomerization, a series of model phosphopeptides with Xaa-Pro motif were designed and synthesized. Electrospray Ionization Mass Spectrometry (ESI-MS) and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS) experiments were performed to study the differences between these two methods in their fragmentation behaviors on the phosphopeptides. It was found that the loss of fragment at m/z 98 was observed not only in the ESI-MS spectra but also in the MALDI spectra, which was due to the loss of phosphate derivatives. The loss of small molecules such as ammonia and water was easier in ESI-MS spectrum. Moreover, the peptidyl-prolyl amide bonds (Xaa-Pro) in the phosphopeptides were prone to cleave in both ESI-MS and MALDI-TOF-MS spectra. The results presented here indicated that ESI-MS was more suitable for small molecule analysis while MALDI-MS was more effective in detection of peptides backbone. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index