Sequence and modified group analysis on C-terminal modified analogs of endomorphin-2 using electrospray ionization-Fourier transform ion cyclotron resonance mass spectrometer

摘要

In this paper,a series of C-terminal modified analogs of endomorphin-2 is investigated using ESI-FT-ICR-MS.Some b,y",a,and internal ions are found in the CID spectra and slight mass differences between the calculated and observed results are obtained.Moreover,if the C-terminal modified group is t-butyloxy,it can lose butene through McLafferty rearrangement.FT-ICR MS shows its power in peptide sequencing successfully helping us obtain the structure of peptide analogs.