Fragment Structures in Collision-Induced Dissociation of Peptides Investigated by H/D Exchange

摘要

We have investigated the structures of CID b ions of peptides via gas phase H/D exchange. (1) Evidence for the presence of two structures in leu-enkephalin b_(4) ion was found. (2) Effect of chain length on the formation of cyclic structure: For (Gly)_(8), the occurrence of cyclic structure was found in the range of b_(4) to b_(7). (3) The chain length will affect the exchange rate of peptide. For (Gly)_(8), the linear oxazolone of b_(6) has the fastest exchange rate whereas its cyclic ring structure has the slowest exchange rate.