(15) Bond cleavage reactions in the tripeptide trialanine upon free electron capture

In the present study we performed dissociative electron attachment (DEA) measurements with the tripeptide trialanine, C₉H₁₇N₃O₄, utilizing a crossed electron-molecular beam experiment with high electron energy resolution (~100 meV). Anion efficiency yields as a function of the incident electron energy are obtained for the most abundant anions up to electron energies of ~4 eV. Quantum chemical calculations are performed to determine the thermochemical thresholds for the anions observed in the measurements. There is no evidence of a molecular anion with lifetime of mass spectrometric timescales. The dehydrogenated closed shell anion (M-H)⁻ is one of the fragment anions observed for which the calculations show that H-loss is energetically possible from carboxyl, as well as amide groups. In contrast to the dipeptide dialanine and monomer alanine the cleavage of the N-C_α bond in the peptide chain is already possible by attachment of electrons at ~0 eV.

Recommended citation: Puschnigg, B., Huber, S. E., Scheier, P., Probst, M., & Denifl, S. (2014). Bond cleavage reactions in the tripeptide trialanine upon free electron capture. The European Physical Journal D, 68, 119.
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