Structural Characterisation of a- and b- Ions Obtained by CID of Peptides using Stable Isotope Labelling, Ion Mobility and Tandem Mass Spectrometry

摘要

Formation of a and b ions (from peptides with a free Nterminus) involves rearrangement. a and b fragment ion species can be mixtures of structures including stable macrocyclic forms. Further fragmentation of a ions occurs by rearrangements. Ion mobility plays a critical role in the clarification of a and b ion structures. Higher mobility resolution may help in the differentiation of isomeric rearrangement products.