Bond cleavage reactions in the tripeptide trialanine upon free electron capture

作者：Puschnigg Benjamin^*; Huber Stefan E; Scheier Paul; Probst Michael; Denifl Stephan

来源：European Physical Journal D, 2014, 68(5): 119.

DOI：10.1140/epjd/e2014-40815-2

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 (similar to 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 similar to 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 (alpha) bond in the peptide chain is already possible by attachment of electrons at similar to 0 eV.

• 出版日期2014-5-9