Open AccessCharge location directs electron capture dissociation of peptide dications
Author(s) -
Yury O. Tsybin,
Kim F. Haselmann,
Mark R. Emmett,
Christopher L. Hendrickson,
Alan G. Marshall
Publication year - 2006
Publication title -
journal of the american society for mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.961
H-Index - 127
eISSN - 1879-1123
pISSN - 1044-0305
DOI - 10.1016/j.jasms.2006.07.024
Subject(s) - chemistry , electron capture dissociation , peptide , protonation , fragmentation (computing) , dissociation (chemistry) , amide , dication , side chain , ion , stereochemistry , peptide sequence , biochemistry , organic chemistry , fourier transform ion cyclotron resonance , polymer , computer science , gene , operating system
The effect of peptide dication charge location on electron capture dissociation (ECD) fragmentation pattern is investigated. ECD fragmentation patterns are compared for peptides with amide and free acid C-terminal groups. ECD of free acid compared with C-terminally amidated peptides with basic residues near the N-terminus demonstrates increased formation of a-type ions. Similarly, ECD of free acid compared with C-terminally amidated peptides with basic residues near the C-terminus exhibits increased formation of y-type ions. Alteration of the peptide sequence to inhibit the formation of charged side chains (i.e., amino acid substitution and acetylation) provides further evidence for charge location effect on ECD. We propose that formation of zwitterionic peptide structures increases the likelihood of amide nitrogen protonation (versus basic side chains), which is responsible for the increase in a- and y-type ion formation.