The Generation of Dehydroalanine Residues in Protonated Polypeptides: Ion/Ion Reactions for Introducing Selective Cleavages

• DOI: 10.1007/s13361-017-1672-5
• Publication Date: 2017-05-11T19:42:52Z
• Authors: Zhou Peng; Jiexun Bu; Scott A. McLuckey
• Keywords: Dehydroalanine; Side chain

We examine a gas-phase approach for converting subset of amino acid residues in polypeptide cations to dehydroalanine (Dha). Subsequent activation the modified ions gives rise specific cleavage N-terminal Dha residue. This process allows incorporation selective cleavages structural characterization ions. An ion/ion reaction within mass spectrometer between multiply protonated and sulfate radical anion introduces site into reactant. collisional cation side chain loss from one several particular chains (e.g., leucine, asparagine, lysine, glutamine, glutamic acid) yield The facilitate preferential backbone produce signature c- z-ions, demonstrated with derived melittin, mechano growth factor (MGF), ubiquitin. efficiencies subsequent generation z-ions have been examined as functions precursor ion charge state conditions using ubiquitin model small protein. It is noted that these are not strongly dependent on trap but sensitive state. Moderate low states show greatest overall yields cleavages, whereas molecule losses water/ammonia) dominate at lowest proton catalyzed amide bond give b- y-ions tend high states.