Structural influences on preferential oxazolone versus diketopiperazine b(2+) ion formation for histidine analogue-containing peptides.

ABSTRACT: Studies of peptide fragment ion structures are important to aid in the accurate kinetic modeling and prediction of peptide fragmentation pathways for a given sequence. Peptide b(2)(+) ion structures have been of recent interest. While previously studied b(2)(+) ions that contain only aliphatic or simple aromatic residues are oxazolone structures, the HA b(2)(+) ion consists of both oxazolone and diketopiperazine structures. The structures of a series of histidine-analogue-containing Xxx-Ala b(2)(+) ions were studied by using action infrared multiphoton dissociation (IRMPD) spectroscopy, fragment ion hydrogen-deuterium exchange (HDX), and density functional theory (DFT) calculations to systematically probe the influence of different side chain structural elements on the resulting b(2)(+) io

SUBMITTER: Gucinski AC 

PROVIDER: S-EPMC3523341 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature