Electron capture dissociation mass spectrometry of phosphopeptides: Arginine and phosphoserine

- The ECD behaviour of phosphorylated model peptides is investigated.
- The position of phosphoserine, arginine, and proline in the sequence is examined.
- Presence of Arg/Lys/Pro and pSer alone does not suppress ECD N-Cα cleavage.
- Increased abundance of fragment ion C-terminal to phosphoserine is observed.
- ECD behaviour appears to depend on peptide conformation rather than sequence.