Characterization of Disulfide Linkages in Peptides Using Tandem Mass Spectrometry (MS~n)

摘要

1. With careful observation and familiarity, MS~3 of internal fragment ions can be used to decipher disulfide bond connecting patterns. 2. In some cases, consecutive disulfide bond opening via C-S bond cleavage may lead to a series of similar b and y ions. 3. To the best of our knowledge, this is the first time that three isomers containing two intrachain disulfide bonds were synthesized and their fragmentation patterns compared side by side. 4. It should be noted, that the P2 peptide was commercially bought, but only two isomers could be successfully synthesized, therefore we do not know what the fragmentation chemistry of the third isomer would have revealed.