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Citation - WoS: 5
Citation - Scopus: 5
Non-Direct Sequence Ions in the Tandem Mass Spectrometry of Protonated Peptide Amides - an Energy-Resolved Study
(American Chemical Society, 2013) Harrison, Alex G.; Taşoğlu, Çağdaş; Yalçın, Talat
The fragmentation reactions of the MH+ ions of Leu-enkephalin amide and a variety of heptapeptide amides have been studied in detail as a function of collision energy using a QqToF beam type mass spectrometer. The initial fragmentation of the protonated amides involves primarily formation of bn ions, including significant loss of NH3 from the MH+ ions. Further fragmentation of these bn ions occurs following macrocyclization/ring opening leading in many cases to bn ions with permuted sequences and, thus, to formation of non-direct sequence ions. The importance of these non-direct sequence ions increases markedly with increasing collision energy, making peptide sequence determination difficult, if not impossible, at higher collision energies. [Figure not available: see fulltext.]

Chemistry / Kimya