Our results indicate that the heterogeneity of precursor ions plays an important role for the ECD of metalated peptides. Typical slow heating ions, including metalated a-/b-ions and non-metalated y-ions, were generated in ECD of Rh(3+) -adducted peptides.īased on the experimental results, it is proposed that (i) for Group IIIB metal ion-peptide complexes, the incoming electron is captured by the proton in the salt-bridge structures of precursor ions (ii) for Rh(3+) -peptide complexes, the incoming electron is captured by the metal ion due to the formation of charge-solvated precursor ions formed through arginine residue-metal coordination. Connection of non-metalated c-ions and metalated z-ions at the position of the serine residue indicated that serine is one of the binding sites of the metal ion on the model peptides. Typical c-/z-ions with and without metal ions were observed in the ECD of peptides adducted with Group IIIB metal ions as charge carriers. Connection of non-metalated c-ions and metalated z-ions at the. Results: Typical c-/z-ions with and without metal ions were observed in the ECD of peptides adducted with Group IIIB metal ions as charge carriers. The ECD experiments were performed on a Bruker APEX III 4.7T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer. The ECD experiments were performed on a Bruker APEX III 4.7T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer.
To further explore the charge carrier effect of metal ions, ECD of peptides adducted with trivalent transition metal ions, including group IIIB (Al(3+), Ga(3+), and In(3+) ) and Rh(3+), were investigated and compared with that of the lanthanide ion (Ln(3+)).īradykinin-derived peptides were used as model peptides to probe the dissociation pathways. It has been reported that transition metal ions could tune the ECD pathway of peptides. The electron capture dissociation (ECD) of proteins/peptides is affected by the nature of charge carrier.