Sequence determination of pharmaceutical peptideS by maldi-tof tandem maSS Spectrometry

Although the peptide ion mechanisms of pre-dissociation, dissociation and postdissociation have been well-studied over the past fifteen years, their practical application still has to be implemented into modern mass spectrometry-driven proteomics and bioanalysis. Unambiguous peptide sequence determination by mass spectrometry relies on the idea that only one continuous series of ions in mass spectrum can assure full sequence determination and meets the requirements of peptide analysis quality. This set of rules defined for the peptide analysis by tandem mass spectrometry would generally improve an overall reliability and data accuracy. Based on the process mechanisms of gas-phase peptide bond dissociation, a relatively small and large model peptides are unambiguously analyzed (bivalirudin and exenatide) showing that derivatization concepts of the Cor N-terminus derivatization (SPITC and Lys-tag) can be avoided.